Chapter 5 Probability Distributions
이 단원에서는 실제로 많이 쓰이는 확률 분포 몇 개와 그 성질들을 간략히 요약하고자 합니다. 확률 분포에 대한 이론적 설명은 모두 (Bishop 2006)의 Appendix B에 있으며 각 분포 별 표본 추출은 (Lemieux 2009)를 참고하였습니다. 과정은 대개 다음과 같이 이루어질 것입니다.
- 확률 분포 정의
- 대푯값(Representative value) 계산
- 최대가능도추정(Maximally Likelihood Estimation)
- Bayesian Update
- Random number generator (Algorithm & Programming with Rust)
편의상 증명은 대부분 영어로 진행하겠습니다.
5.1 Binary Variables
5.1.1 Bernoulli Distribution
| Definition 5.1.1 - Bernoulli distribution |
| Let consider a single binary random variable \(\small x\in\{0,1\}\). Suppose the probability of \(\small x=1\) is given as \(\small p(x=1|\mu) = \mu\) where \(\small 0\leq \mu \leq 1\) then \[\small\text{Bern}(x|\mu) = \mu^x(1 - \mu)^{1-x}\] is called Bernoulli distribution. |
| Property 5.1.2 - Representative values of Bernouli distribution |
| Let \(\small\text{Bern}(x|\mu)\) be given Bernoulli distribution. Then \[\small\begin{aligned} \mathbb{E}[x] &= \mu \\ \text{var}[x] &= \mu(1-\mu) \end{aligned}\] |
| Theorem 5.1.3 - MLE for Bernoulli distribution |
| Let \(\small\mathcal{D} = \{x_1, \cdots, x_N\}\) be i.i.d data belong to \(\small\text{Bern}(x|\mu)\). Applying maximally likelihood estimation, then \[\small\mu_{ML} = \frac{1}{N}\sum_{i=1}^N x_n \] |
Proof for Thm 5.1.3
Since there is i.i.d assumption, the likelihood given as \[\small p(\mathcal{D}|\mu) = \prod_{n=1}^N p(x_n | \mu) = \prod_{n=1}^N \mu^{x_n} (1 - \mu)^{1-x_n}\] For convenience, let’s obtain log likelihood. \[\small\begin{aligned} \ln p(\mathcal{D}| \mu) = \sum_{n=1}^N \ln p(x_n | \mu) &= \sum_{n=1}^N \left\{x_n \ln \mu + (1-x_n)\ln(1-\mu) \right\}\\ &= \ln \mu \sum_{n=1}^N x_n + \ln(1-\mu) \sum_{n=1}^N (1-x_n) \\ &= (\ln\mu - \ln(1-\mu))\sum_{n=1}^N x_n + N \ln(1-\mu) \end{aligned}\] Then for MLE, let’s differentiate log likelihood with \(\mu\). \[\small\frac{\partial}{\partial \mu}\ln p(\mathcal{D}|\mu) = \frac{1}{\mu}\sum_{n=1}^N x_n - \frac{1}{1-\mu}\sum_{n=1}^N (1 - x_n) = 0\] Therefore we can find \(\small \mu_{ML}\). \[\small\therefore\,\mu_{ML} = \frac{1}{N}\sum_{n=1}^N x_n\]
이번에는 균등 분포(Uniform distribution)로 부터 베르누이 분포를 구현해보도록 하겠습니다.
| Algorithm 5.1.4 - Uniform to Bernoulli |
| We want to generate \(\small X \sim \text{Bern}(x | \mu)\). 1. Generate \(\small U \sim \text{Unif}(0,1)\) 2. If \(\small U \leq \mu\) where \(\mu \in [0, 1]\) then \(X = 1\) else \(X = 0\). |
이 간단한 알고리즘을 Rust를 이용해서 나타내면 다음과 같습니다.
// Generate 100 samples of Bern(x|0.1)
extern crate rand;
use self::rand::prelude::*;
fn main() {
let sample_size = 100;
let mut rng = thread_rng();
let mut v = vec![0usize; 100];
let mu: f64 = 0.1;
for i in 0 .. sample_size {
let u = rng.gen_range(0f64, 1f64);
if u <= mu {
v[i] = 1;
} else {
v[i] = 0;
}
}
println!("Samples:\n{:?}", v);
}
이미 구현되어 있는 라이브러리인 Peroxide을 사용한 결과는 다음과 같습니다.
extern crate peroxide;
use peroxide::*;
fn main() {
let b = Bernoulli(0.1);
let b_samples = b.sample(100);
b.print();
}
5.1.2 Beta Distribution
| Definition 5.1.5 - Beta Distribution |
| The Beta distribution is a family of continuous probability distributions defined on the interval \(\small[0, 1]\) parametrized by two positive shape parameters, denoted by \(\small\alpha\) and \(\small\beta\) : \[\small \text{Beta}(\mu | \alpha, \beta) = \frac{\Gamma(\alpha + \beta)}{\Gamma(\alpha)\Gamma(\beta)} \mu^{\alpha-1}(1-\mu)^{\beta - 1}\] |
| Property 5.1.6 - Normalization of Beta distribution |
| \[\small \int_0^1 \text{Beta}(\mu | \alpha, \beta) d\mu = 1\] |
Proof for Prop 5.1.6
To prove this, we should show next relation. \[\small \int_0^1 \mu^{\alpha - 1}(1 - \mu)^{\beta - 1}d\mu = \frac{\Gamma(\alpha)\Gamma(\beta)}{\Gamma(\alpha + \beta)}\] Then let’s start proof. \[\small\begin{aligned} \Gamma(\alpha)\Gamma(\beta) &= \int_0^\infty \mu^{\alpha - 1}e^{-\mu}d\mu \int_0^\infty \nu^{\beta - 1}e^{-\nu}d\nu \\ &= \int_0^\infty \int_0^\infty \mu^{\alpha - 1}\nu^{\beta-1}e^{-(\mu + \nu)} d\mu d\nu \\ &= \int_0^\infty \left(\int_\mu^\infty \mu^{\alpha-1}(t-\mu)^{\beta - 1} e^{-t} dt\right)d\mu \\ \end{aligned}\]
For last line of above equations, I used the substitution \(t = \mu + \nu,~ dt = d\nu\). Next, let change order of integration. \[\small\begin{aligned} \Gamma(\alpha)\Gamma(\beta) &= \int_0^\infty \left(\int_0^t \mu^{\alpha-1}(t-\mu)^{\beta-1}d\mu\right)e^{-t}dt \\ &= \int_0^\infty \left(\int_0^1 (t\mu')^{\alpha-1}t^{\beta-1}(1-\mu')^{\beta-1}t d\mu'\right)e^{-t}dt \\ &= \int_0^\infty \left(\int_0^1 t^{\alpha + \beta - 1} \mu'^{\alpha-1} (1- \mu')^{\beta-1} d\mu'\right)e^{-t}dt \\ &= \int_0^\infty t^{\alpha + \beta - 1} e^{-t}dt \cdot \int_0^1 \mu'^{\alpha-1}(1-\mu')^{\beta-1}d\mu' \end{aligned}\]
\[\small\therefore \int_{0}^1 \mu^{\alpha - 1}(1-\mu)^{\beta-1}d\mu = \frac{\Gamma(\alpha)\Gamma(\beta)}{\Gamma(\alpha + \beta)}\]
Then proof is finish.
| Property 5.1.7 - Representative values of Beta distribution |
| Let \(\small\text{Beta}(\mu | \alpha, \beta)\) be a given Beta distribution, then \[\small\begin{aligned} \mathbb{E}[\mu] &= \frac{\alpha}{\alpha + \beta} \\ \text{var}[\mu] &= \frac{\alpha \beta}{(\alpha + \beta)^2(\alpha + \beta + 1)} \\ \text{mode}[\mu] &= \frac{\alpha - 1}{\alpha + \beta - 2} \end{aligned}\] |
Proof for prop 5.1.7
First, let’s see expectation value. \[\small\begin{aligned} \mathbb{E}[\mu] &= \int_0^1 \mu \cdot \text{Beta}(\mu|\alpha, \beta)d\mu \\ &= \frac{\Gamma(\alpha + \beta)}{\Gamma(\alpha)\Gamma(\beta)} \int_0^1 \mu \cdot \mu^{\alpha - 1}(1 - \mu)^{\beta - 1} d\mu \\ &= \frac{\Gamma(\alpha + \beta)}{\Gamma(\alpha)\Gamma(\beta)} \int_0^1 \mu^{\alpha}(1-\mu)^{\beta-1}d\mu \\ &= \frac{\Gamma(\alpha + \beta)}{\Gamma(\alpha)\Gamma(\beta)} \cdot \frac{\Gamma(\alpha + 1)\Gamma(\beta)}{\Gamma(\alpha + \beta + 1)} \\ &= \frac{\alpha}{\alpha + \beta} \end{aligned}\]
Next, see variation. \[\small\begin{aligned} \text{var}[\mu] &= \int_0^1 \mu^2 \cdot \text{Beta}(\mu | \alpha, \beta)d\mu - \left(\frac{\alpha}{\alpha + \beta}\right)^2 \\ &= \frac{\Gamma(\alpha + \beta)}{\Gamma(\alpha)\Gamma(\beta)} \cdot \frac{\Gamma(\alpha + 2)\Gamma(\beta)}{\Gamma(\alpha + \beta + 2)} - \left(\frac{\alpha}{\alpha + \beta}\right)^2 \\ &= \frac{\alpha(\alpha + 1)}{(\alpha + \beta)(\alpha + \beta + 1)} - \left(\frac{\alpha}{\alpha + \beta}\right)^2 \\ &= \frac{\alpha \beta}{(\alpha + \beta)^2(\alpha + \beta + 1)} \end{aligned}\]
Before viewing mode, we should differentiate Beta distribution under specific condition. \(\small(\alpha, \beta > 1)\). \[\small \frac{\partial}{\partial \mu}\text{Beta}(\mu | \alpha, \beta) = \frac{\Gamma(\alpha + \beta)}{\Gamma(\alpha)\Gamma(\beta)} \left((\alpha- 1) \mu^{\alpha - 2}(1 - \mu)^{\beta - 1} - (\beta - 1)\mu^{\alpha - 1}(1 - \mu)^{\beta - 2} \right)\]
Thus, we can find value of \(\mu\) directly. \[\small\begin{aligned} &(\alpha - 1)(1 - \mu) - (\beta - 1)\mu = 0 \\ \Rightarrow ~ &\mu = \frac{\alpha - 1}{\alpha + \beta - 2} \end{aligned}\]
| Algorithm 5.1.8 - Acceptance Rejection Method |
| For given pdf \(\small \varphi(x)\) which is defined on \(\small \mathcal{D}\), let \(\small t(x)\) be a function
such that \(\small t(x) \geq \varphi(x), ~\forall x \in \mathcal{D}\) with next property:
\[\small T = \int_{\mathcal{D}} t(x) dx \geq \int_{\mathcal{D}} \varphi(x) dx = 1\]
Since \(\displaystyle\small r(x) \equiv \frac{t(x)}{T}\) is density function, we generate \(\small r(x)\) instead of \(\small t(x)\) with following procedure: 1. Generate \(\small Y\) having density \(\small r(x)\). 2. Generate \(\small U \sim \text{Unif}(0,1)\), independent of \(\small Y\). 3. If \(\displaystyle \small U \leq \frac{\varphi(Y)}{t(Y)}\), then return \(\small X=Y\); otherwise go back to step 1. |
Proof for Algorithm 5.1.8
Through above 3 steps, we can generate the pair \(\small (Y,U)\). To be accepted, a pair must satisfy \(\displaystyle\small U \leq \frac{\varphi(Y)}{t(Y)}\). Thus, pdf of \(\small X\) is equivalent to pdf of \(\small(Y|U \leq \varphi(Y) / t(Y))\). Therefore,
\[\small P(X\leq x) = P\left(Y\leq x \left\lvert U\leq \frac{\varphi(Y)}{t(Y)}\right.\right) = \frac{P(Y\leq x, U\leq\varphi(Y)/t(Y))}{P(U\leq \varphi(Y)/t(Y))}\]
And we can find what the RHS is.
\[\small \begin{aligned} P\left(Y\leq x, U\leq \frac{\varphi(Y)}{t(Y)}\right) &= \int_{-\infty}^{x} P\left( U \leq \frac{\varphi(y)}{t(y)}\right) r(y) dy = \int_{-\infty}^{x} \frac{\varphi(y)}{t(y)}r(y) dy \\ &= \frac{1}{T}\int_{-\infty}^x \varphi(y) dy = \frac{F(x)}{T} \end{aligned}\]
\[\small P\left(U \leq \frac{\varphi(Y)}{t(Y)} \right) = \int_{-\infty}^{\infty} \frac{\varphi(y)}{t(y)}r(y) dy = \frac{1}{T}\]
Therefore the CDF of \(\small X\) becomes \(\small F(x)\) which is CDF corresponding to \(\small \varphi(x)\).
이제 증명도 마쳤으니 이 알고리즘을 구현해봅시다.
extern crate rand;
extern crate peroxide;
use rand::prelude::* // For RNG
use peroxide::special::function::beta; // For Beta function
fn main() {
// For Beta(x | 3, 2)
let a = 3f64;
let b = 2f64;
let n = 100usize; // For 100 samples
// Two independent RNG
let mut rng1 = thread_rng();
let mut rng2 = thread_rng();
let mut result = vec![0f64; n];
let mut iter_num = 0usize;
// To construct t(x) -> t(x) = T (constant function)
// T >= φ(x), ∀x ∈ D => T = mode
// r(x) = t(x)/T = 1 ~ Unif(0,1)
let mode_x = (a - 1f64) / (a + b - 2f64);
let mode = beta_pdf(mode_x);
while iter_num < n {
// 1. Y ~ Unif(0, 1)
let u1 = rng1.gen_range(0f64, 1f64);
// 2. U ~ Unif(0, 1)
let u2 = rng2.gen_range(0f64, 1f64);
// 3. U <= varphi(Y) / t(Y)
if u2 <= beta_pdf(u1) / c {
v[iter_num] = u1;
iter_num += 1;
}
}
println!("{:?}", v);
}
fn beta_pdf(x: f64, a: f64, b: f64) -> f64 {
1f64 / beta(a, b)
* x.powf(a - 1f64)
* (1f64 - x).powf(b - 1f64)
}
다음은 Peroxide
라이브러리에서의 위와 동일한 코드 사용법 입니다.
(내부 구현도 동일합니다.)
extern crate peroxide;
use peroxide::*;
fn main() {
let beta = Beta(3, 2);
beta.sample(100).print();
}
References
Bishop, Christopher M. 2006. Pattern Recognition and Machine Learning. Springer. https://www.springer.com/kr/book/9780387310732.
Lemieux, Christiane. 2009. Monte Carlo and Quasi-Monte Carlo Sampling. 1st ed. Springer Series in Statistics. Springer-Verlag New York. https://www.springer.com/us/book/9780387781648.


Everything that is part of this project is 100% original. All images,
sprites, sprite sheets and scripts included were created using Github's
Atom Programming Text Editor, Adobe Photoshop, and Adobe Illustrator.
However, this project was not done without research.
A couple of the SVG
buildings featured in the background of the first level of the Physics
of Ninjas Game are loosely based off of those found in the open source
image uploaded to wikimedia.org which can be found
here.
I learned the JavaScript language throughout the duration
of this project by researching problems as I ran into them and
stackoverflow.com proved
to be a major asset due to its large database of experienced active
members who have a large repositoire of answered questions behind them.
Also, I followed a guide posted on williammalone.com
by William Malone in 2014 on creating spritesheets for animation. The realtime
physics engine I created, which was arguably one of the more difficult parts
of this project for me, was created after reading a heuristic guide on
building various types of physics engines found here
and written by Adam Ranfelt from IBM on November 20th, 2012 (Note:
only general ideas from this guide were utilized and no code or methods
for accomplishing a task were copied).
The physics behind the game has varying ranges of complexities
but is partially based off of lectures given in class over kinematics,
kinetic friction, gravity, and conversation of momentum. In order to
slow the ninja down when in contact with surfaces, I created a kinetic
friction property as part of my physics engine and based these amounts off
of findings from the article Coefficient of Friction from school-for-champions.com
written by Ron Kurtus on November 2nd 2005. The inspiration for the
application of physics by a ninja however comes from a variety of sources
including this one.
The repository for all source code concerned in this project
can be found on my GitHub page
and is provided under an open source MIT license (can be used without
restriction as long as author is credited). From this link the repository can
be cloned/downloaded and unzipped to run offline. Note: This code was tested
using Google Chrome V. 54 on macOS Sierra and due to time constraints, proper
cross browser/platform testing was not extensively done so all behaviour
can only be guaranteed for this browser and operating system.


India's forex reserves rise by $1.8 bn to a new lifetime high of $442.5 bn
The overall kitty had expanded by $1.04 billion to $440.751 billion in the previous reporting week
by Press Trust of IndiaIndia's forex reserves increased by $1.832 billion to a new lifetime high of $442.583 billion in the week ended October 25, helped by a jump in core currency assets and value of gold, RBI data showed on Friday.
The overall kitty had expanded by $1.04 billion to $440.751 billion in the previous reporting week.
For the week under review, foreign currency assets, which are the biggest part of the reserves, increased by $1.642 billion to $410.453 billion, as per the data.
Expressed in US dollar terms, the foreign currency assets include the effect of appreciation or depreciation of non-US units like the euro, pound and the yen held in the foreign exchange reserves.
The value of the gold reserves increased by $191 million to $27.052 billion for the week.
The special drawing rights with the International Monetary Fund was up by $1 million to $1.441 billion.
The country's reserve position with the Fund dipped by $2 million to $3.637 billion, the data showed.


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Silex ユーザーガイド
チェンジログ¶
1.2.0 (2013-XX-XX)¶
- Reverted “convert attributes on the request that actually exist”
- [BC BREAK] Routes are now always added in the order of their registration (even for mounted routes)
- Added run() on Route to be able to define the controller code
- Deprecated TwigCoreExtension (register the new HttpFragmentServiceProvider instead)
- Added HttpFragmentServiceProvider
- Allowed a callback to be a method call on a service (before, after, finish, error, on Application; convert, before, after on Controller)
1.1.3 (2013-XX-XX)¶
- Fixed translator locale management
1.1.2 (2013-10-30)¶
- Added missing “security.hide_user_not_found” support in SecurityServiceProvider
- Fixed event listeners that are registered after the boot via the on() method
1.0.2 (2013-10-30)¶
- Fixed SecurityServiceProvider to use null as a fake controller so that routes can be dumped
1.1.1 (2013-10-11)¶
- Removed or replaced deprecated Symfony code
- Updated code to take advantages of 2.3 new features
- Only convert attributes on the request that actually exist.
1.1.0 (2013-07-04)¶
- Support for any Psr\Log\LoggerInterface as opposed to the monolog-bridge one.
- Made dispatcher proxy methods on, before, after and error lazy, so that they will not instantiate the dispatcher early.
- Dropped support for 2.1 and 2.2 versions of Symfony.
1.0.1 (2013-07-04)¶
- Fixed RedirectableUrlMatcher::redirect() when Silex is configured to use a logger
- Make DoctrineServiceProvider multi-db support lazy.
1.0.0 (2013-05-03)¶
2013-04-12: Added support for validators as services.
2013-04-01: Added support for host matching with symfony 2.2:
$app->match('/', function() { // app-specific action })->host('example.com'); $app->match('/', function ($user) { // user-specific action })->host('{user}.example.com');
2013-03-08: Added support for form type extensions and guessers as services.
2013-03-08: Added support for remember-me via the RememberMeServiceProvider.
2013-02-07: Added Application::sendFile() to ease sending BinaryFileResponse.
2012-11-05: Filters have been renamed to application middlewares in the documentation.
2012-11-05: The before(), after(), error(), and finish() listener priorities now set the priority of the underlying Symfony event instead of a custom one before.
2012-11-05: Removing the default exception handler should now be done via its disable() method:
Before:
unset($app[‘exception_handler’]);
After:
$app[‘exception_handler’]->disable();
2012-07-15: removed the monolog.configure service. Use the extend method instead:
Before:
$app['monolog.configure'] = $app->protect(function ($monolog) use ($app) { // do something });
After:
$app['monolog'] = $app->share($app->extend('monolog', function($monolog, $app) { // do something return $monolog; }));
2012-06-17: ControllerCollection now takes a required route instance as a constructor argument.
Before:
$controllers = new ControllerCollection();
After:
$controllers = new ControllerCollection(new Route()); // or even better $controllers = $app['controllers_factory'];
2012-06-17: added application traits for PHP 5.4
2012-06-16: renamed request.default_locale to locale
2012-06-16: Removed the translator.loader service. See documentation for how to use XLIFF or YAML-based translation files.
2012-06-15: removed the twig.configure service. Use the extend method instead:
Before:
$app['twig.configure'] = $app->protect(function ($twig) use ($app) { // do something });
After:
$app['twig'] = $app->share($app->extend('twig', function($twig, $app) { // do something return $twig; }));
2012-06-13: Added a route before middleware
2012-06-13: Renamed the route middleware to before
2012-06-13: Added an extension for the Symfony Security component
2012-05-31: Made the BrowserKit, CssSelector, DomCrawler, Finder and Process components optional dependencies. Projects that depend on them (e.g. through functional tests) should add those dependencies to their composer.json.
2012-05-26: added boot() to ServiceProviderInterface.
2012-05-26: Removed SymfonyBridgesServiceProvider. It is now implicit by checking the existence of the bridge.
2012-05-26: Removed the translator.messages parameter (use translator.domains instead).
2012-05-24: Removed the autoloader service (use composer instead). The *.class_path settings on all the built-in providers have also been removed in favor of Composer.
2012-05-21: Changed error() to allow handling specific exceptions.
2012-05-20: Added a way to define settings on a controller collection.
2012-05-20: The Request instance is not available anymore from the Application after it has been handled.
2012-04-01: Added finish filters.
2012-03-20: Added json helper:
$data = array('some' => 'data'); $response = $app->json($data);
2012-03-11: Added route middlewares.
2012-03-02: Switched to use Composer for dependency management.
2012-02-27: Updated to Symfony 2.1 session handling.
2012-01-02: Introduced support for streaming responses.
2011-09-22: ExtensionInterface has been renamed to ServiceProviderInterface. All built-in extensions have been renamed accordingly (for instance, Silex\Extension\TwigExtension has been renamed to Silex\Provider\TwigServiceProvider).
2011-09-22: The way reusable applications work has changed. The mount() method now takes an instance of ControllerCollection instead of an Application one.
Before:
$app = new Application(); $app->get('/bar', function() { return 'foo'; }); return $app;
After:
$app = new ControllerCollection(); $app->get('/bar', function() { return 'foo'; }); return $app;
2011-08-08: The controller method configuration is now done on the Controller itself
Before:
$app->match('/', function () { echo 'foo'; }, 'GET|POST');
After:
$app->match('/', function () { echo 'foo'; })->method('GET|POST');


Corss-Platform Online Education Design
FOXUS
WORKING WORKS · Web Design
Intell-Driven
Medical Records MGMT
Service Design
Hopsicle
Unity 3D Game Design
Happy New Year
Tangible Interaction Design
Say with Flowers
Industrial Design
Modu Table
FIND ME BY sxczqxty1994@163.com


Gets a detail about the given song. ## Syntax
musicDetail(detail: <#Type (WFContentItemPropertyName)#>, music: <#Variable#>)
musicDetail(detail: Title, music: Favorite Song)


Transaction and Isolation Notes
Postmodern transaction calls with transaction names and isolation levels
Transactions are one or more statements wrapped together which either all succeed and are "committed" or none of them succeed, in which case any state changes are rolled back to the beginning of the transaction. In the case of postmodern, there are two main macros available for use:
- with-transaction (for general use)
- with-logical-transaction (for nested transactions and savepoints)
When you get into situations where you expect concurrent transactions, you can specify the whether the transaction is allowed only read access or both read and write access to the database table rows and you can specify either the default isolation level or a specific isolation level for that transaction. If you need more information on what isolation levels are, and when to use them, see below.
Postgresql defaults to the read committed isolation level with read and write access. This is also postmodern's default, but that can be changed by setting postmodern:*isolation-level* to your desired setting.
The available settings in postmodern follow the sql standard are:
- :read-committed-rw (read committed with read and write)
- :read-committed-ro (read committed with read only)
- :repeatable-read-rw (repeatable read with read and write)
- :repeatable-read-ro (repeatable read with read only)
- :serializable (serializable with read and write)
(Ok. "Loosely" follows the sql standard because we combine read-write and read-only constraints with the sql standard isolation levels. There is one unsafe isolation level defined by the standard, but neither postgresql nor any other major database implements it.)
Postmodern generally provides the ability to specify the name of a transaction and the isolation level per the key words above. Examples of use are below and "george" is used as the name of the transaction (not quoted or as a string):
(with-transaction () (execute (:insert-into 'test-data :set 'value 77))) (with-transaction (george) (execute (:insert-into 'test-data :set 'value 22))) (with-transaction (george :read-committed-rw) (execute (:insert-into 'test-data :set 'value 33))) (with-transaction (:serializable) (execute (:insert-into 'test-data :set 'value 44))) (with-logical-transaction () (execute (:insert-into 'test-data :set 'value 77))) (with-logical-transaction (george) (execute (:insert-into 'test-data :set 'value 22))) (with-logical-transaction (george :read-committed-rw) (execute (:insert-into 'test-data :set 'value 33))) (with-logical-transaction (:serializable) (execute (:insert-into 'test-data :set 'value 44)))
Introduction to ACID, Transactions and Isolation Levels
Databases like Postgresql are not simply data storage, they are transaction management systems. In the context of transactions with multiple operations within the transaction, either all of them commit or none of them commit (the transaction is rolled back). Transactions include single statement transactions as well as multiple statement transactions that are wrapped inside BEGIN – COMMIT Commands. (In the case of postmodern macros with-transaction and with-logical-transaction, the commit command is handled for you automatically.)
You may have heard of databases being "ACID" compliant or having ACID functionality. Transactions are the “A” (Atomicity) in “ACID”. “C” is “Consistency”, “I” is “Isolation” and “D” is “Durability”. As you can tell, everything in ACID in designed to maintain the integrity of the data. Without atomicity, you risk leaving data in a partial or invalid state and everything which depends on the data will break. (And your dba will be upset – the question is – will they then try to break you?)
Consistency ensures that every transaction will move the database from one valid state to another valid state. Consider two users A and B signing up with the same desired username “myname” almost simultaneously. The system checks to see whether “myname” is in use for A. It is not, so it starts the process of creating a record for “myname”. The system checks for B to see whether “myname” is in use. Since it has not yet finished creating the record for A, it appears to be available for B, so it starts the process of creating a user record for B using “myname”. One or both can end up in an invalid state.
You can prevent the inconsistent state by either putting a uniqueness check on the user table for usernames or you use an isolation level like serializable on your transactions. In either case, B’s commit will fail, you have to restart that transaction, but the data that is now in the system is safe and consistent..
Isolation levels define what is allowed to happen if there are two transactions tyring to access the same data simultaneously. More on this below.
Durability means that committed transactions must stay committed, even in the event of a crash, power loss, etc.
Transactions
It is easy show the impact of transactions in action. Consider the following:
(execute (:create-table test-data ((value :type integer)))) (with-transaction () (execute (:insert-into 'test-data :set 'value 77))) (query (:select '* :from 'test-data)) ((77))
The postmodern macro with-transaction completes with a call to commit-transaction. So absent any intervening actions, the transaction will commit at the end of the form.
For purposes of the following examples, assume that we truncated the table prior to each example so we have the same base line each time.
(ignore-errors (with-transaction () (execute (:insert-into 'test-data :set 'value 2)) (error "no wait"))) NIL #<SIMPLE-ERROR "no wait" {100D581653}> (with-test-connection (query (:select '* :from 'test-data))) NIL
This time we triggered an error before the transaction concluded. Because the error was inside the transaction, it invalidated all statements inside the transction and the tentative insertion never happened. (Actually more complicated than this, but from an application developer standpoint, we can think of it this way.)
Now lets actually give the transaction a name and make a superflous call to commit-transaction within the transaction.
(with-transaction (transaction) (execute (:insert-into 'test-data :set 'value 2)) (commit-transaction transaction)) (query (:select '* :from 'test-data)) ((2))
As you can see, making the unnecessary call to commit-tranaction does not trigger the insertion twice.
We can also decide to abort the transaction without triggering an error:
(with-transaction (transaction) (execute (:insert-into 'test-data :set 'value 44)) (abort-transaction transaction)) (query (:select '* :from 'test-data)) NIL
As expected, the insertion was never committed due to the call to abort-transaction.
What happens if we nest transactions?
Postgresql does not fully support nested transactions. Full support of nested transactions would mean that a succesful sub-transaction does not get rolled back if a parent transaction (direct or indirect) gets rolled back.
Postgresql allows the use of savepoints, which can get you to a consistent state but means that if any transaction in a nested transaction sequence is rolled back, then everything in the transaction is rolled back. Postmodern provides savepoints automatically in a nested situation if you use the macro with-logical-transaction. Postmodern also provides a macro with-savepoint if you need to handle them manually.
If you do not use savepoints, the result of nested transactions may not be consistent. Some or all of subtransactions may or may not get committed if there is an error anywhere in the nest.
The official postgresql documentation states that "Issuing a begin when already inside a transaction will provoke a warning message. The state of the transaction is not affected." While this sounds like the subtransactions just get treated as part of the outer transaction, you cannot rely on that interpretation.
Morale of the story. If you are going to nest transactions in postmdern, use the with-logical-transaction macro, do not use the with-transaction macro.
Now lets talk about concurrency issues and the trade-offs between different isolation levels.
The Concurrency Problem
Summary
Consider when you have multiple concurrent transactions or multiple concurrent database events. These create potential race conditions as well as potential overwrite issues, creating hard to find bugs. The base problem is easy to understand – what happens when two users try to access the same row of data concurrently.
Think about how databases using MVCC (multi-version concurrency control) execute statements inside a transaction. The data generated by the transaction is kept off to the side, away from other data until the entire transaction can be committed. Once it is committed, it becomes visible to all future transactions and the old row which it may have edited becomes marked as invalid. The invalid row still exists in the system until the next VACUUM. Of course, this does not mean that the system prevents user B from overwriting user A’s changes from an hour ago. We are solely focused on concurrency issues here.
All committed transactions are written to the write-ahead log (WAL or “xlog”). In case of trouble, Postgresql can replay the WAL log to recover changes that did not get into the actual data files. Postgresql also has a commit log “pg_xact” which summarizes transactions and whether the transaction committed or aborted. Any transaction that was a read only transaction is never written to the WAL or commit logs. As it was not intended to modify any data, there is no need. However, if the transaction is aborted, that fact will still be noted in the WAL and commit logs. (You can also configure postgresql to log all queries, but that is not the default.)
Now think about the situation at a little more granular level.
- If two transactions read the old state and then perform changes concurrently, the last write transaction will be effective and the previous write transaction may be lost unless you have explicit locking.
- If two transactions with multiple statements read the old state and then both transactions perform changes concurrently, you may end up in an inconsistent data state.
- If one transaction reads the old state and prepares to make a change based on the value of the old state, but another transaction modifies the old state before the first transaction finishes, the first transaction has now made a decision based on bad data.
- If you execute the same query twice and get back more or fewer elements in the second execution than the first execution.
Depending on your application, these may or may not be something that you need to worry about.
The SQL standard actually has four transaction isolation levels. Postgresql only implements three of those - "Read Uncommitted" is not implemented and the default transaction level for Postgresql is “read committed”. Postgresql allows the user to specify the isolation level of a transaction on a transaction by transaction basis. As you might expect, there are trade-offs. Stronger isolation levels have more overhead and may trigger more transactions that need to be repeated (and therefore you will have to write the code to handle the necessary repeats).
We explain this table just below:
| Isolation Level | Dirty Read | Nonrepeatable Read | Phantom Read | Serialization Anomaly |
|---|---|---|---|---|
| Read Uncommitted | Allowed | Possible | Possible | Possible |
| Read Committed * | Not Possible | Possible | Possible | Possible |
| Repeatable Read | Not Possible | Not Possible | Allowed by SQL Standard, not allowed in Postgresql | Possible |
| Serializable | Not Possible | Not Possible | Not Possible | Not Possible |
Problem Explanation
Dirty Read
A Dirty Read is a transaction reads data written by a concurrent uncommitted transaction. You can specify a transaction as having a “Read Uncommitted” level, but Postgresql will internally just give you a “Read Committed” isolation level.
Assume sales are 2100 at the beginning
| Transaction 1 | Transaction 2 |
| BEGIN | BEGIN |
| (:select 'sales :from 'table1 :where (:= 'id 21) | |
| (:update 'table1 :set 'sales 2200 :where (:= 'id 21)) ;no commit | |
| (:select 'sales :from 'table1 :where (:= 'id 21) | |
| END | END |
The second select will read sales as 2200 even though Transaction 2 did not fully commit.
Nonrepeatable Read
A Nonrepeatable read is a transaction re-reads data it has previously read and finds the data has been modified by another transaction that committed since the initial read.
Assume sales are 2100 at the beginning
| Transaction 1 | Transaction 2 |
| BEGIN | BEGIN |
| (:select 'sales :from 'table1 :where (:= 'id 21) | |
| (:update 'table1 :set 'sales 2200 :where (:= 'id 21)) | |
| COMMIT; | |
| (:select 'sales :from 'table1 :where (:= 'id 21) | |
| END | END |
The second select will read sales as 2200. At least transaction 2 actually committed first.
If you are just trying to avoid lost updates, you can use row level locks with select FOR UPDATE under read committed. That avoids the update being lost or aborted. Of course, now you need to worry about how to handle situations where one transaction gets stalled and holds a transaction too long.
For select statements, you can add a row level lock by adding FOR SHARE to the end of the SELECT. For updates, use FOR UPDATE. In postmodern, if you are using s-sql, you can include :for-share or :for-update in the select statement. E.g.
(query (:for-update (:select :* :from 'foo 'bar 'baz) :of 'bar 'baz :nowait))
See s-sql.html for further details.
Phantom Read
A Phantom Read is where a transaction re-executes a query returning a set of rows and finds that the set of rows has changed (not necessarily row 215, but some one or more of the rows in the query set). Phantom Reads are prevented by using the “Repeatable Read” isolation level. Row level locks will not solve this problem.
Assume first select returns 50:
| Transaction 1 | Transaction 2 |
| BEGIN | BEGIN |
| (:select (:count '*) :from 'table1 :where (:= 'region 1)) | |
| (:insert-into 'table1 :set 'sales 2200)) | |
| COMMIT; | |
| (:select (:count '*) :from 'table1 :where (:= 'region 1)) | |
| END | END |
The second select will return 51. Depending on what else might be happening in transaction 1, the difference between the number of rows at the beginning and the number of rows at the end may cause calculations to be inconsistent internally to the transaction.
For More Fun
Now consider you have banking application A which runs in multiple sessions and does not use transactions and the user withdraws 100 from each of two sessions and the balance started at 300.
| Session 1 | Session 2 |
| (:select 'balance :from 'accounts :where (:= 'user-id 1)) | |
| (:select 'balance :from 'accounts :where (:= 'user-id 1)) | |
| Application calculates the balance should be 200 | |
| (:update 'accounts :set 'balance 200) | |
| Application calculates the balance should be 200 | |
| (:update 'accounts :set 'balance 200) |
At this point the application has subtracted 200 (100 in each session), but the account balance still shows 200. Transactions would not have made a difference.
Now implemented slightly differently:
| Session 1 | Session 2 |
| (:select 'balance :from 'accounts :where (:= 'user-id 1)) | |
| (:select 'balance :from 'accounts :where (:= 'user-id 1)) | |
| (:update 'accounts :set 'balance (:- 'balance 100)) | |
| (:update 'accounts :set 'balance (:- 'balance 100)) |
Do you know what the balance is now? It should be 100 because you put the calculation back into the database where it belongs. But life gets more complicated than these simple examples. Complex queries and updates provide more possibilities for concurrent transactions to generate conflicting, leading to solutions such as "row level locking" and "isolation levels".
Isolation Levels
The official postgresql documentation can be found here.
Read Committed Isolation Level
Read Committed is the default isolation level in Postgresql. In general it has the best balance between locking and performance. This isolation level means that the existing row is read after the transaction is completed but not yet written. If the row has not changed, then the transaction is executed. If the row has changed from when it started building the transaction, then it starts the transaction over again.
The “Read Committed” default isolation level is safe when you are concurrently reading. If there are multiple select statements in a single transaction, each select statement will have its own snapshot of the database (which might not be the same if another transaction is concurrently modifying the database). The “Read Committed” isolation level is not necessarily safe for concurrent updates. In other words, the concurrent updates would be performed serially, potentially surprising the user whose commit is overridden. Update and Delete statements in a “Read Committed” isolation level will create a snapshot of the database, use that snapshot to find the rows matching the where clause and then try to lock that row of the snapshot. If any rows are already locked by an update or delete statement in another transaction, the update or delete statement will wait for the other transaction to commit or abort. If it commits, the update or delete will re-evaluate the where clause on the new version of the row to determine whether it needs to be modified.
Assume our banking problem using transactions at the Postgresql default isolation level of "read committed".
| Session 1 | Session 2 |
| BEGIN | BEGIN |
| (:select 'balance :from 'accounts :where (:= 'user-id 1)) | |
| ; Deferred (:select 'balance :from 'accounts :where (:= 'user-id 1)) | |
| Application calculates the balance should be 200 | |
| (:update 'accounts :set 'balance 200) | |
| COMMIT | |
| Application calculates the balance should be 100 | |
| (:update 'accounts :set 'balance 100) | |
| COMMIT |
The Session 2 select query notices that the row is already engaged and would be deferred until Transaction 1 is committed. At that point it reads the balance (now 200), tells the application, and the application subtracts 100 and tells the database to update the balance to 100.
Repeatable Read Isolation Level
In Postgresql, a “Repeatable Read” isolation level takes a snapshot of the current state of the database and all queries in the transaction will use that snapshot. So if another transaction modifies a row, a second select statement in a repeatable read isolation level would not be affected because it is looking solely at the snapshot that was taken at the beginning of the transaction.
Things happen differently if the transaction using a “Repeatable Read” isolation level wants to Update or Delete a row.
If a Phantom read is detected when the transaction wants to commit, a Repeatable Read would go back and re-read the table and repeat the transaction. Update and Delete statements in a “Repeatable Read” isolation level will create a snapshot of the database, use that snapshot to find the rows matching the where clause and then check to see if another transaction is currently trying to modify the rows (not just the columns) that the Update or Delete statement is trying to modify. If the other transaction aborts, the Update or Delete statement will modify the relevant rows and continue. If the other transaction commits, then the repeatable read transaction will abort with an error message about “could not serialize access due to concurrent update”.
If you are running transaction at isolation level “repeatable read”, concurrent updates can be expected to trigger query failures from time to time that need to be handled, typically by re-running the transaction. The following error message can be expected:
- “ERROR: could not serialize due to concurrent update” (Under
either “repeatable read” or “serializable”.)
Repeatable read addresses a different problem than our banking problem above, so the result in this case is the same as "read committed".
Serializable Isolation Level
The Serializable Isolation level tells postgresql to effectively serialize all transactions. That ensures validity at the cost of a hit to performance.
If you are running transaction at isolation level “serializable”, concurrent updates can be expected to trigger query failures from time to time that need to be handled, typically by re-running the transaction. The following two errors can be expected:
- “ERROR: could not serialize due to concurrent update” (Under either “repeatable read” or “serializable”.)
- “ERROR: could not serialize access due to read/write dependencies among transactions. (Under “serializable”).
For Futher Reading
- https://www.postgresql.org/docs/current/static/transaction-iso.html
- https://www.postgresql.org/docs/current/static/sql-set-transaction.html
- http://elliot.land/post/sql-transaction-isolation-levels-explained
- https://blog.2ndquadrant.com/postgresql-anti-patterns-read-modify-write-cycles/
- https://dba.stackexchange.com/questions/131226/set-serializable-isolation-for-update-query-postgresql-9-4
- https://www.enterprisedb.com/docs/en/9.0/pg/transaction-iso.html
- https://wiki.postgresql.org/wiki/SSI
- https://dba.stackexchange.com/questions/202775/how-to-write-validation-trigger-which-works-with-all-isolation-levels
- https://stackoverflow.com/questions/45923021/apparent-transaction-isolation-violation-in-postgresql
- https://brandur.org/http-transactions
- https://brandur.org/idempotency-keys
- https://brandur.org/postgres-reads
- http://malisper.me/postgres-transaction-isolation-levels/
- https://begriffs.com/posts/2017-08-01-practical-guide-sql-isolation.html (includes the "zoo" of transaction phenomena)
- http://shiroyasha.io/transaction-isolation-levels-in-postgresql.html
- A Critique of ANSI SQL Isolation Levels
- A Read-Only Transaction Anomaly Under Snapshot Isolation
- Serializable Snapshot Isolation in PostgreSQL
- https://www.postgresql.org/docs/current/static/applevel-consistency.html
- The Transaction Concept: Virtues and Limitations


{% extends '../tutorials/tutbaselayout.html' %} {% load static %} {% block content %}
Arrays a kind of data structure that can store a fixed-size sequential collection of elements of the same type. An array is used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.
Instead of declaring individual variables, such as number0, number1, ..., and number99, you declare one array variable such as numbers and use numbers[0], numbers[1], and ..., numbers[99] to represent individual variables. A specific element in an array is accessed by an index.
All arrays consist of contiguous memory locations. The lowest address corresponds to the first element and the highest address to the last element.
To declare an array in C, a programmer specifies the type of the elements and the number of elements required by an array as follows −
type arrayName [ arraySize ];
This is called a single-dimensional array. The arraySize must be an integer constant greater than zero and type can be any valid C data type. For example, to declare a 10-element array called balance of type double, use this statement −
double balance[10];
Here balance is a variable array which is sufficient to hold up to 10 double numbers.
You can initialize an array in C either one by one or using a single statement as follows −
double balance[5] = {1000.0, 2.0, 3.4, 7.0, 50.0};
The number of values between braces { } cannot be larger than the number of elements that we declare for the array between square brackets [ ].
If you omit the size of the array, an array just big enough to hold the initialization is created. Therefore, if you write −
double balance[] = {1000.0, 2.0, 3.4, 7.0, 50.0};
You will create exactly the same array as you did in the previous example. Following is an example to assign a single element of the array −
balance[4] = 50.0;
The above statement assigns the 5th element in the array with a value of 50.0. All arrays have 0 as the index of their first element which is also called the base index and the last index of an array will be total size of the array minus 1. Shown below is the pictorial representation of the array we discussed above −
An element is accessed by indexing the array name. This is done by placing the index of the element within square brackets after the name of the array. For example −
double salary = balance[9];
The above statement will take the 10th element from the array and assign the value to salary variable. The following example Shows how to use all the three above mentioned concepts viz. declaration, assignment, and accessing arrays −
#include <stdio.h>
int main() {
int n[ 10 ]; /* n is an array of 10 integers */
int i,j;
/* initialize elements of array n to 0 */
for ( i = 0; i < 10; i++ ) {
n[ i ] = i + 100; /* set element at location i to i + 100 */
}
/* output each array element's value */
for ( j = 0; j < 10; j++ ) {
printf("Element[%d] = %d\n", j, n[j] );
}
return 0;
}
When the above code is compiled and executed, it produces the following result −
Element[0] = 100 Element[1] = 101 Element[2] = 102 Element[3] = 103 Element[4] = 104 Element[5] = 105 Element[6] = 106 Element[7] = 107 Element[8] = 108 Element[9] = 109
Arrays are important to C and should need a lot more attention. The following important concepts related to array should be clear to a C programmer −
| Sr.No. | Concept & Description |
|---|---|
| 1 | C supports multidimensional arrays. The simplest form of the multidimensional array is the two-dimensional array. |
| 2 | You can pass to the function a pointer to an array by specifying the array's name without an index. |
| 3 | C allows a function to return an array. |
| 4 | You can generate a pointer to the first element of an array by simply specifying the array name, without any index. |


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Notebooks
Story: !gweh or Malkop Gift (poisons)
!gweh or Malkop Gift (poisons)
Title
!gweh or Malkop Gift (poisons)
Collection
Summary
Bushman poisons: their names given in Bushman, but the remarks respecting them in English only, after ≠kásin (L IV.-1. 3472-3480). Names and descriptions of poisons, including where they are found and how they are used and prepared, and their effects on people and the game they have shot for eating.
Comments
1) Date on p.3479: 10 November, 2) This story is found in Book IV-1
Contributors
Date
10 November 1873 (finished on or about)
Categories
Custom and daily life, Plants and animals
Keywords
poisons (!gweh or Malkop Gift) , poisons (poisonous plants) , poisons (used by Koranna) , poisons (used by |xam) , poisons (the preparation of) , poisons (combinations of different) , poisons (and wounds) , poisons (used in hunting) , poisons (and eating game) , poisons (bartering for) , poisons (the effects of) , poisons (prohibitions relating to) , poisons (that kill people) , poisons (and weapons) , poisons (and intoxication) , poisons (and gender) , poisons (from ≠kasin's place) , poisons (from snakes) , poisons (the names of different) , poisons (where they are found) , poisons (descriptions of) , plants (used in making of poisons) , plants (the names of) , snakes (used in making of poisons) , snakes (the names of) , names (of plants used for making poisons) , names (of poisons) , names (Dutch and |xam) , names (of poisonous snakes) , bartering (for poison) , Koranna (poisons used by) , intoxication (and poisonous plants) , weapons (and poisons) , game (eating poisoned) , game (effects of poison on) , game (poisoning of weapons used for hunting) , place (poisons found at ≠kasin's) , ≠kasin's (poisons found at his place)
Story Pages
3472-3480


A natural number with defined lower and upper bounds beyond which its value will never pass.
More...
|
| | ClampedNaturalNumber (const NatT &value, NatT min, NatT max) |
| | Constructs a new ClampedNaturalNumber with the specified current, minimum, and maximum values. More...
|
| |
|
virtual | ~ClampedNaturalNumber ()=default |
| | Provides a virtual destructor with the default dehavior.
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator+= (const NatT &other) |
| | Adds the given number to this one, as constrained by this number's bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator-= (const NatT &other) |
| | Subtracts the given number from this one, as constrained by this number's bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator*= (const NatT &other) |
| | Multiplies this number by the one given, as constrained by this number's bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator/= (const NatT &other) |
| | Divides this number by the one given, as constrained by this number's bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator%= (const NatT &other) |
| | Sets this number's value to the remainder of division by the given number, within this number's bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator++ () |
| | Increments this number by one, within its bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > & | operator-- () |
| | Decrements this number by one, within its bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > | operator++ (int) |
| | Increments this number by one, within its bounds. More...
|
| |
| virtual ClampedNaturalNumber< NatT > | operator-- (int) |
| | Decrements this number by one, within its bounds. More...
|
| |
| | BasicClampedNumber ()=delete |
| | The default constructor is disabled. More...
|
| |
| | BasicClampedNumber (const NatT &value, const NatT &min, const NatT &max) |
| | Constructs a new BasicClampedNumber with the specified current, minimum, and maximum values. More...
|
| |
|
virtual | ~BasicClampedNumber ()=default |
| | Provides a virtual destructor with the default dehavior.
|
| |
| virtual const NatT & | value () const final |
| | Returns this number's current value by const reference. More...
|
| |
| virtual const NatT & | value (const NatT &newVal) final |
| | Sets this number's current value, as constrained by its bounds. More...
|
| |
| virtual const NatT & | maxValue () const final |
| | Returns this number's current maximum value by const reference. More...
|
| |
| virtual const NatT & | maxValue (const NatT &newMax) final |
| | Sets this number's maximum value to that specified. More...
|
| |
| virtual const NatT & | minValue () const final |
| | Returns this number's current minimum value by const reference. More...
|
| |
| virtual const NatT & | minValue (const NatT &newMin) final |
| | Sets this number's minimum value to that specific. More...
|
| |
| virtual const NatT & | minimize () final |
| | Sets this number's current value to its maximum. More...
|
| |
| virtual const NatT & | maximize () final |
| | Sets this number's current value to its minimum. More...
|
| |
| virtual bool | operator== (const BasicClampedNumber< NatT > &other) const |
| | Returns whether this number equals the other. More...
|
| |
| virtual bool | operator!= (const BasicClampedNumber< NatT > &other) const |
| | Returns whether this number is not equal to the other. More...
|
| |
| virtual bool | operator< (const BasicClampedNumber< NatT > &other) const |
| | Returns whether this number is less than the other. More...
|
| |
| virtual bool | operator<= (const BasicClampedNumber< NatT > &other) const |
| | Returns whether this number is less than or equal to the other. More...
|
| |
| virtual bool | operator> (const BasicClampedNumber< NatT > &other) const |
| | Returns whether this number is greater than the other. More...
|
| |
| virtual bool | operator>= (const BasicClampedNumber< NatT > &other) const |
| | Returns whether this number is greater than or equal to the other. More...
|
| |
| virtual | operator NatT () const final |
| | Allows the excplicit conversion of this BasicClampedNumber to an instance of NumT , the numerical type it wraps. More...
|
| |
| virtual | operator bool () const final |
| | Allows the explicit conversion of this BasicClampedNumber to a boolean value. More...
|
| |
|
(Note that these are not member functions.)
|
| template<typename NatT > |
| ClampedNaturalNumber< NatT > | operator+ (const ClampedNaturalNumber< NatT > &lhs, const NatT &rhs) |
| | Returns a new BasicClampedNumber with a value equal to that of the original, plus the given number, within the clamped number's bounds. More...
|
| |
| template<typename NatT > |
| ClampedNaturalNumber< NatT > | operator- (const ClampedNaturalNumber< NatT > &lhs, const NatT &rhs) |
| | Returns a new ClampedNaturalNumber with a value equal to that of the original, minus the given number, within the clamped nunber's bounds. More...
|
| |
| template<typename NatT > |
| ClampedNaturalNumber< NatT > | operator* (const ClampedNaturalNumber< NatT > &lhs, const NatT &rhs) |
| | Returns a new ClampedNaturalNumber with a value equal to that of the original, multiplied by the given number, within the clamped nunber's bounds. More...
|
| |
| template<typename NatT > |
| ClampedNaturalNumber< NatT > | operator/ (const ClampedNaturalNumber< NatT > &lhs, const NatT &rhs) |
| | Returns a new ClampedNaturalNumber with a value equal to that of the original, divided by the given number, within the clamped nunber's bounds. More...
|
| |
| template<typename NatT > |
| ClampedNaturalNumber< NatT > | operator% (const ClampedNaturalNumber< NatT > &lhs, const NatT &rhs) |
| | Returns a new ClampedNaturalNumber holding the remainder of the division of the original by the given number, within this number's bounds. More...
|
| |
template<typename NatT>
class clamped::ClampedNaturalNumber< NatT >
A natural number with defined lower and upper bounds beyond which its value will never pass.
A ClampedNaturalNumber
corresponds with unsigned integral types such as size_t
and unsigned int
, and the mathematical set of all natural numbers.
In addition to the comparison operator requirements for custom numeric types wrapped by a BasicClampedNumber
, a NatT
wrapped by a ClampedNaturalNumber
must also be comparable against non-negative int
s, namely zero and one. It must be assignabe to the int
value zero, and must implement the arithmetic compound assignment operators - plus modulo (+=, -=, *=, /=, %=) with another NatT
as right operand.
- Parameters
-
| NatT | the unsigned integral type being wrapped |
- See also
- ClampedInteger


Welcome to my blog, berry nice, great success!
Here's your lucky number:
First paragpraph will go here, along with more material. Maybe you shoul make an unordered list with your links of work to stunt with.
Here's your lucky number:
First paragpraph will go here, along with more material. Maybe you shoul make an unordered list with your links of work to stunt with.


Labour could ban private jets to stop billionaires 'trashing the climate'
Jeremy Corbyn's party will consider a ban within six years to cut carbon emissions if it wins the election after research found private jets pump out same amount as 450,000 cars every year
by Pippa Crerar, https://www.mirror.co.uk/authors/pippa-crerar/Labour will consider a ban on private jets in just six years’ time to help cut carbon emissions if it wins the election.
Shadow transport secretary Andy McDonald accused billionaires of being allowed to “trash the climate” at the expense of the less well off.
It came as a think tank report revealed that private jets pump out carbon emissions the equivalent of 450,000 cars each year.
Labour would consult with the industry about the date to phase out fossil-fuel private planes - and support the expansion of electric aircraft.

“Climate targets cannot be met without curbing pollution from air travel, and a passenger on a private jet produces ten times the emissions of someone on a regular flight. This simply cannot be ignored.
“In just a few years’ time it will be possible for these journeys to be made by electric aircraft – so long as government puts in place the right incentives.
“Labour will examine these proposals closely and consult with industry on the introduction of a phase out date for the use of fossil fuel private jets.”
The Common Wealth report found that 128,000 flights between UK and EU airports were made using private jets in 2018, representing 6 per cent of all UK air traffic. A further 14,000 trips were made to destinations outside Europe.
A private flight from London to New York was equivalent to driving a typical UK car non-stop for four and a half years, it said.
Industry estimates suggest that private jets are empty on about 40 per cent of journeys, as they are moved to be in place for the super-rich and corporate customers who use them.
Almost half of all private jet traffic in Britain passes through five airports around London, given its status as the home to the most billionaires in Europe and one of the world’s biggest financial centres.
Labour has made green issues a central plank of its campaign ahead of the December 12 election.


I always believe in providing the best quality service. I love to do communication in details with my clients and give daily updates of work. Are you looking for a person who is able to do your job in the best way and at a certain time? Please don't hesitate to send me an invitation to your valuable interview. Thanks
I am a reliable freelancer who delivers high quality solution on time at a very reasonable price.
My prices are more than reasonable and affordable compared to the service quality you will get, so please do not hesitate to request a quote if you need an expert scraper / crawler. I can provide scraped data in whatever format you want: csv, excel, xml, mysql etc. I can also provide you the program i used to scrape that website. I am developing my programs in java and you may run them on windows, mac and linux/unix machines.
I will provide the rquirment on Direct Email & Direct Phone Number Collect Information-Finding Executive Leads-Like: Owner, Co-Founder, President, CEO, CFO, CTO, CMO, COO and So More C-Level, VP-Level, Director-Level, Manager-Level, Non-Manager, Consulting, Engineering & Technical, Finance & Administration, Human Resources, Legal, Operations, Sales, Marketing, Medical & Health, Scientists etc
I will provide the rquirment on Direct Email & Direct Phone Number Collect Information-Finding Executive Leads-Like: Owner, Co-Founder, President, CEO, CFO, CTO, CMO, COO and So More C-Level, VP-Level, Director-Level, Manager-Level, Non-Manager, Consulting, Engineering & Technical, Finance & Administration, Human Resources, Legal, Operations, Sales, Marketing, Medical & Health, Scientists etc
I will provide the rquirment on Direct Email & Direct Phone Number Collect Information-Finding Executive Leads-Like: Owner, Co-Founder, President, CEO, CFO, CTO, CMO, COO and So More C-Level, VP-Level, Director-Level, Manager-Level, Non-Manager, Consulting, Engineering & Technical, Finance & Administration, Human Resources, Legal, Operations, Sales, Marketing, Medical & Health, Scientists etc
I will provide the rquirment on Direct Email & Direct Phone Number Collect Information-Finding Executive Leads-Like: Owner, Co-Founder, President, CEO, CFO, CTO, CMO, COO and So More C-Level, VP-Level, Director-Level, Manager-Level, Non-Manager, Consulting, Engineering & Technical, Finance & Administration, Human Resources, Legal, Operations, Sales, Marketing, Medical & Health, Scientists etc
I will provide the rquirment on Direct Email & Direct Phone Number Collect Information-Finding Executive Leads-Like: Owner, Co-Founder, President, CEO, CFO, CTO, CMO, COO and So More C-Level, VP-Level, Director-Level, Manager-Level, Non-Manager, Consulting, Engineering & Technical, Finance & Administration, Human Resources, Legal, Operations, Sales, Marketing, Medical & Health, Scientists etc
It won’t be a bigger problem to find one video game lover in your neighbor. Since the introduction of Virtual Game, it has been achieving great heights so far as its popularity and technological advancement are concerned. The history of video game is as interesting as a fairy tale.
Professional Freelancer
skype : sakib258324
<EMAIL_ADDRESS>Hire Me Go To Our WebsiteJuly 2015 to Present
All users on MySpace will know that there are millions of
people out there. Every day besides.
May 2013 to Present
All users on MySpace will know that there are millions of
people out there. Every day besides.
Session: 2010-11
Result: 3.78 (In the Scale of 4.00)
Session: 2006-09
Result: 3.40 (In the Scale of 4.00)
Session: 2003-06
Result: 4.94 (In the Scale of 5.00)
I found this person extremely easy to work with. I had a very quick deadline and he was able to make this deadline and his work was very good and thorough. He was very professional and responsive to communication.
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I have worked with Sakib on about 10 different projects now. He's helped me scrape thousands of emails from different sources and build my lists for cold email and cold calling. He's very reasonably priced, knows how to stick to deadlines and is very good with communication! I'll be hiring him again soon.
Great to work with as usual always goes over and beyond to make sure the job is complete . I would recommend to any small or large project
Design By : Sakib reza ( Lead Cyber Army )


breakfast
lunch
dinner
is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
Great Food! Menu is awesome, there foods are not only great but
also in the right price . i'll highly recomend them:)


{% extends "base.html" %} {% load staticfiles %} {% block title %} Ricky Catron: Home {% endblock %} {% block description %} I am a web developer in the early stages of my career. I attend Rochester Institute of Technology as a Web and Mobile Computing major. {% endblock %} {% block content %}
I am a web developer in the early stages of my career. I attend Rochester Institute of Technology as a Web and Mobile Computing major. In class I have learned about HTML, CSS, JavaScript, Design, Java, and PHP. On my own I like to write python web apps using the Flask or Django frameworks. Currently I am working to learn more about devops, automation, user experience, JavaScript, and its many frameworks. In addition to my web experience I have worked in general IT as a Helpdesk Tech and my team was featured in the local paper during high school for our work with the raspberry pi micro computer. Outside of work I like music, snowboarding, and cooking. Overall I am eager to start my career and continue to learn.


Police find body in search for missing Tyneside pensioner Stephen Robertson
Stephen Robertson's family have been informed of the discovery after he was reported missing on Wednesday
by Kathryn RiddellA body has been found in the search for a missing man who had not been seen for 24 hours.
Police recovered the body of a man while searching for Stephen Robertson from South Shields on Thursday.
The 63-year-old was reported missing after last being seen at 8.30am on Wednesday.
The body found is believed to be Stephen and his next of kin have been informed and are being supported by officers.
A formal identification process is due to take place and an investigation is being carried out to establish the circumstances surrounding his death.
At this stage, detectives do not believe the death is suspicious.
A spokesperson for Northumbria Police said: "Police would like to thank everyone who helped with the search for Stephen, and we would like to ask that his family’s privacy is respected at this difficult time."


Spectra is the first all ladies hackathon in the west coast taking place in the Bay Area! This is a unique event to bring together high schoolers, college students, and women in technology from all over.
The goal is to provide a safe and inviting environment for women to experiment with technology without any sort of apprehension. Free from gender stereotypes, this all ladies hackathon will give our attendees the space to breathe and work comfortably in tech to hone their skills. The overarching goal would be to make them comfortable enough with their own skills before taking on the maledominated tech industry.
We hope to gather over 400 beautiful ladies and supporters to come together on July 22nd to July 24th for a 36 hour hackathon to learn new skills, inspire each other, and build longlasting connections! We want to give more ladies the opportunity to make an impact in Computer Science.
More details are coming soon!
Please enter your email address


The Show Manager has been introduced in QLC+ starting from version 4.0.0, after forking the original
QLC code on November 5th, 2012.
This feature is meant to give users the possibility of setting up a time driven show in a friendly and
completely graphical way.
The graphic interface shows a multitrack view, typical of audio sequencers or video editing softwares,
and with it users are allowed to place QLC+ Functions at the desired
place and time in the view.
A typical use case are those gigs where bands play songs following a metronome and the light show has
always to be the same, following the music.
Another case are visual entertainment shows, where dancers or singers follow some music and lights create
the atmosphere at the right time.
| Create a new Show. A Show is represented as a multitrack workspace where tracks, sequences and audio elements can be added | |
| Shows list | This drop down box list the currently created Shows. Clicking on a Show will display it. |
| Create a new track. In QLC+ a track corresponds to a Scene. A Show can have a virtually infinite number of tracks. | |
| Create a new Sequence item. A sequence is a special type of Chaser bound to a Scene. All the steps created in a sequence will only act on DMX channels of the selected track. | |
| Create a new audio item. An audio item simply represents
an audio file. Audio items can be added on any track, but if you want to to create a separate
track for it, just create an empty Scene track. Note: It is possible to display the waveform preview of an audio item just by right clicking it and selecting the channels you want to display (mono, left channel, right channel, stereo) Warning: Even though QLC+ allows you to, it is not possible to play two audio files simultaneously. Especially on Windows, you might experience unwanted crashes. |
|
| Copy the currently selected item into QLC+ clipboard | |
Paste QLC+ clipboard content at the cursor position. When performing this
operation two checks are performed:
|
|
| Delete the currently selected item. This can be a sequence, an audio item or a track.
Note that deleting a track will delete also all its sequences/audio children. Note: Show Manager will only perform a "visual removal" of functions. To permanently delete them, please use the Function Manager |
|
| Assign a custom colour to the selected item | |
| Enable/disable the "Snap to grid" functionality. The view will be filled with vertical bars
corresponding to the header markers (time or BPM) Snapping to grid will correct your items by dragging them to the nearest reference bar |
|
| 00:00:00.000 | This field displays the cursor time position both if the playback is stopped or activated |
| Start the current Show playback from the cursor position | |
| Stop the current Show playback. Clicking once will stop the cursor at the current position
for resuming later. Clicking twice will restore the cursor to 0 seconds. Hint: When resuming a show with audio tracks, please keep in mind that audio accuracy depends on the file formats you are using. For example MP3 files resume is not particularly accurate, while Wave files resume is. |
|
| Time markers | This drop down menu lets you to choose the desired time division to display for your Show. This can be either 'Time'. 'BPM 4/4', 'BPM 3/4' or 'BPM 2/2' |
| BPMs | When a BPM time division mode is selected, this field lets you decide the appropriate BPM
to set for you Show. This ranges from 20 to 240. This can be quite useful when dealing with electronic music or BPM synchronized shows |


PART III. DISCLOSURE OF PERSONAL RECORDS
Note
Part heading amended by L 1989, c 192, §5.
[§92F-21] Individual's access to own personal record. Each agency that maintains any accessible personal record shall make that record available to the individual to whom it pertains, in a reasonably prompt manner and in a reasonably intelligible form. Where necessary the agency shall provide a translation into common terms of any machine readable code or any code or abbreviation employed for internal agency use. [L 1988, c 262, pt of §1]


MAP (Members Attending Parliament) tracks the attendance of Indian MPs in Lok Sabha (lower house).
Currently data for 15th Lok Sabha is presented. Data for 12 sessions has been included.
Class information
- 1st class - 75% and above attendance
- 2nd class - 65% to 75% attendance
- 3rd class - below 65% attendance
Idea
Conceptualized this idea, thanks to a
Tweet.
Data
Data has been accessed from
Lok Sabha website.
Data is
available in CSV format. Data can
potentially be corrupted at few places. Please report to
@bkamapantula.
Data format
Id, MP Name, Number of days signed, Number of days missed, Gender, State, Party, Constituency
Code
Code for parsing the data out of the Lok Sabha website will be made available soon.
To contribute, head to
Github.
To-do
- State-wise MP attendance
- Day-wise MP attendance
- Overall analysis


Enjoy the happy array of insane cat gifs I have for you and being 31. Hope you have an as amazing year as I know you will. Much Love -N


val downloader: CompactBlockDownloader
the component responsible for downloading compact blocks and persisting them locally for processing.
downloader
- the component responsible for downloading compact blocks and persisting them
locally for processing.


| Modifier and Type | Field and Description |
|---|---|
protected GF2mField |
field
finite field GF(2^m)
|
protected int[][] |
matrix
For the matrix representation the array of type int[][] is used, thus
every element of the array keeps one element of the matrix (element from
finite field GF(2^m))
|
MATRIX_TYPE_RANDOM_LT, MATRIX_TYPE_RANDOM_REGULAR, MATRIX_TYPE_RANDOM_UT, MATRIX_TYPE_UNIT, MATRIX_TYPE_ZERO, numColumns, numRows
| Modifier | Constructor and Description |
|---|---|
|
GF2mMatrix(GF2mField field,
byte[] enc)
Constructor.
|
protected |
GF2mMatrix(GF2mField field,
int[][] matrix)
Constructor.
|
|
GF2mMatrix(GF2mMatrix other)
Copy constructor.
|
| Modifier and Type | Method and Description |
|---|---|
Matrix |
computeInverse()
Compute the inverse of this matrix.
|
boolean |
equals(java.lang.Object other)
Checks if given object is equal to this matrix.
|
byte[] |
getEncoded() |
int |
hashCode() |
boolean |
isZero()
Check if this is the zero matrix (i.e., all entries are zero).
|
Vector |
leftMultiply(Vector vector)
Compute the product of a vector and this matrix.
|
Matrix |
rightMultiply(Matrix a)
Compute the product of this matrix and another matrix.
|
Matrix |
rightMultiply(Permutation perm)
Compute the product of this matrix and a permutation.
|
Vector |
rightMultiply(Vector vector)
Compute the product of this matrix and a vector.
|
java.lang.String |
toString() |
getNumColumns, getNumRows
protected GF2mField field
protected int[][] matrix
public GF2mMatrix(GF2mField field, byte[] enc)
field
- a finite field GF(2^m)enc
- byte[] matrix in byte array formpublic GF2mMatrix(GF2mMatrix other)
other
- another GF2mMatrix
protected GF2mMatrix(GF2mField field, int[][] matrix)
field
- a finite field GF(2^m)matrix
- the matrix as int array. Only the reference is copied.public byte[] getEncoded()
getEncoded
in class Matrix
public boolean isZero()
public Matrix computeInverse()
computeInverse
in class Matrix
public Matrix rightMultiply(Matrix a)
Matrix
rightMultiply
in class Matrix
a
- the other matrixpublic Matrix rightMultiply(Permutation perm)
Matrix
rightMultiply
in class Matrix
perm
- the permutationpublic Vector leftMultiply(Vector vector)
Matrix
leftMultiply
in class Matrix
vector
- a vectorpublic Vector rightMultiply(Vector vector)
Matrix
rightMultiply
in class Matrix
vector
- a vectorpublic boolean equals(java.lang.Object other)
equals
in class java.lang.Object
other
- objectpublic int hashCode()
hashCode
in class java.lang.Object


Our school motto is " Forward Ever Backward Never":", the capacity that we normally admit especially in Form1 is 200 students annually.
Our school admission policy is to admit a student with minimum 300 marks scored in KCPE, Our rules and regulations policies are friendly and easy to adhere to,The environment is conducive for learning
Our school motto is " Forward Ever Backward Never":", the capacity that we normally admit especially in Form1 is 200 students annually.
Our school admission policy is to admit a student with minimum 300 marks scored in KCPE, Our rules and regulations policies are friendly and easy to adhere to,The environment is conducive for learning
© 2017 Ongeng sec school . All Rights Reserved | Design by kenoxfirm


Apply a model stack to create different types of predictions.
# S3 method for model_stack
predict(object, new_data, type = NULL, members = FALSE, opts = list(), ...)
| object | A model stack with fitted members outputted from |
|---|---|
| new_data | A rectangular data object, such as a data frame. |
| type | Format of returned predicted values—one of "numeric", "class",
or "prob". When NULL, |
| members | Logical. Whether or not to additionally return the predictions for each of the ensemble members. |
| opts | A list of optional arguments to the underlying predict function passed on to parsnip::predict.model_fit for each member. |
| ... | Additional arguments. Currently ignored. |
This package provides some resampling objects and datasets for use in examples and vignettes derived from a study on 1212 red-eyed tree frog embryos!
Red-eyed tree frog (RETF) embryos can hatch earlier than their normal 7ish days if they detect potential predator threat. Researchers wanted to determine how, and when, these tree frog embryos were able to detect stimulus from their environment. To do so, they subjected the embryos at varying developmental stages to "predator stimulus" by jiggling the embryos with a blunt probe. Beforehand, though some of the embryos were treated with gentamicin, a compound that knocks out their lateral line (a sensory organ.) Researcher Julie Jung and her crew found that these factors inform whether an embryo hatches prematurely or not!
Note that the data included with the stacks package is not necessarily a representative or unbiased subset of the complete dataset, and is only for demonstrative purposes.
reg_folds
and class_folds
are rset
cross-fold validation objects
from rsample
, splitting the training data into for the regression
and classification model objects, respectively. tree_frogs_reg_test
and
tree_frogs_class_test
are the analogous testing sets.
reg_res_lr
, reg_res_svm
, and reg_res_sp
contain regression tuning results
for a linear regression, support vector machine, and spline model, respectively,
fitting latency
(i.e. how long the embryos took to hatch in response
to the jiggle) in the tree_frogs
data, using most all of the other
variables as predictors. Note that the data underlying these models is
filtered to include data only from embryos that hatched in response to
the stimulus.
class_res_rf
and class_res_nn
contain multiclass classification tuning
results for a random forest and neural network classification model,
respectively, fitting reflex
(a measure of ear function) in the
data using most all of the other variables as predictors.
log_res_rf
and log_res_nn
, contain binary classification tuning results
for a random forest and neural network classification model, respectively,
fitting hatched
(whether or not the embryos hatched in response
to the stimulus) using most all of the other variables as predictors.
See ?example_data
to learn more about these objects, as well as browse
the source code that generated them.
# \donttest{
# see the "Example Data" section above for
# clarification on the data and tuning results
# objects used in these examples!
data(tree_frogs_reg_test)
data(tree_frogs_class_test)
# build and fit a regression model stack
reg_st <-
stacks() %>%
add_candidates(reg_res_lr) %>%
add_candidates(reg_res_sp) %>%
blend_predictions() %>%
fit_members()
reg_st
#> ── A stacked ensemble model ─────────────────────────────────────
#>
#> Out of 10 possible candidate members, the ensemble retained 3.
#> Penalty: 0.1.
#> Mixture: 1.
#>
#> The 3 highest weighted members are:
#> # A tibble: 3 x 3
#> member type weight
#> <chr> <chr> <dbl>
#> 1 reg_res_lr_1_1 linear_reg 0.349
#> 2 reg_res_sp_2_1 linear_reg 0.303
#> 3 reg_res_sp_8_1 linear_reg 0.267
# predict on the tree frogs testing data
predict(reg_st, tree_frogs_reg_test)
#> # A tibble: 143 x 1
#> .pred
#> <dbl>
#> 1 40.4
#> 2 111.
#> 3 90.6
#> 4 33.8
#> 5 75.3
#> 6 90.0
#> 7 122.
#> 8 82.4
#> 9 37.6
#> 10 77.3
#> # … with 133 more rows
# include the predictions from the members
predict(reg_st, tree_frogs_reg_test, members = TRUE)
#> # A tibble: 143 x 4
#> .pred reg_res_lr_1_1 reg_res_sp_8_1 reg_res_sp_2_1
#> <dbl> <dbl> <dbl> <dbl>
#> 1 40.4 38.0 34.3 36.9
#> 2 111. 124. 117. 98.6
#> 3 90.6 84.5 92.4 98.2
#> 4 33.8 35.3 28.0 23.8
#> 5 75.3 79.0 77.0 67.6
#> 6 90.0 83.7 92.2 97.3
#> 7 122. 118. 139. 123.
#> 8 82.4 80.0 79.2 88.0
#> 9 37.6 36.5 30.7 32.7
#> 10 77.3 79.4 78.0 72.8
#> # … with 133 more rows
# build and fit a classification model stack
class_st <-
stacks() %>%
add_candidates(class_res_nn) %>%
add_candidates(class_res_rf) %>%
blend_predictions() %>%
fit_members()
#> ! Bootstrap05: preprocessor 1/1, model 1/1: from glmnet Fortran code (error code -61); ...
#> ! Bootstrap09: preprocessor 1/1, model 1/1: from glmnet Fortran code (error code -73); ...
#> ! Bootstrap11: preprocessor 1/1, model 1/1: from glmnet Fortran code (error code -65); ...
#> ! Bootstrap18: preprocessor 1/1, model 1/1: from glmnet Fortran code (error code -79); ...
#> ! Bootstrap19: preprocessor 1/1, model 1/1: from glmnet Fortran code (error code -77); ...
#> ! Bootstrap23: preprocessor 1/1, model 1/1: from glmnet Fortran code (error code -82); ...
#> Error in { asNamespace("stacks")$fit_member(name = mem, wflows = model_stack[["model_defs"]], members_map = members_map, train_dat = dat)} task 2 failed - "This engine requires some package installs: 'ranger'"
class_st
#> Error in eval(expr, envir, enclos) object 'class_st' not found
# predict reflex, first as a class, then as
# class probabilities
predict(class_st, tree_frogs_class_test)
#> Error in predict(class_st, tree_frogs_class_test) object 'class_st' not found
predict(class_st, tree_frogs_class_test, type = "prob")
#> Error in predict(class_st, tree_frogs_class_test, type = "prob") object 'class_st' not found
# returning the member predictions as well
predict(
class_st,
tree_frogs_class_test,
type = "prob",
members = TRUE
)
#> Error in predict(class_st, tree_frogs_class_test, type = "prob", members = TRUE) object 'class_st' not found
# }


The Whole Bean | Branding & Identity Design
Overview
The development of an entire brand & identity package for The Whole Bean coffee shop as they prepare to launch a grand opening. This includes supporting the vision through development of a unique branding personality and designing a complete collection of identity design deliverables.
My Role
Use branding psychology to create a connection through brand personality and related components, building a sense of loyalty among the audience. The identity design deliverables include a typescale, color scheme, collection of brand images, logo, icon pair, social media header and brand style guide.
The Customer
Karla Kahvi has funding and a great location in a popular neighborhood to open a coffee shop. Her strength lies in managing the business and financial side of her shop, but she wanted someone else to take over the design and development of a brand and identity for her coffee shop that fits her products and resonates within the neighborhood.
The Product
The product line will include coffee drinks (drip coffee and basic espresso drinks), a variety of loose leaf teas, and simple food offerings such as seasonal fresh fruit and baked goods like muffins and scones, as well as quick bites like veggie wraps, sandwiches, and granola bars. The menu is completely plant-based with a focus on whole foods with gluten-free options.
Brand Mission Statement
Declaring the brand's purpose, values, and goals through its mission statement:
“To nourish and inspire the body and mind.”
Brand Psychology
In order to establish and maintain a connection with an audiences it’s important to understand the psychology behind brand personality, color, typography, pattern recognition and social belonging. Some research into successful brands helps with this understanding of audience expectations and delivering consistently on them.
Brand Personality
Reviewing the 5 personality dimensions of brand personality and their associated traits, The Whole Bean has characteristics that make it clear it falls under the dimension of Sincerity. The brand is sincere, wholesome, down-to-earth, family-oriented, warm, welcoming, peaceful, comforting, healthy and friendly with an artistic edge.
Inspirational Mood Board
BUILDING A BRAND
Personality & Identity
A brand's personality and identity are connected on a deep level. The personality includes human traits associated with it and the emotional connection formed with its audience, whereas the brand's identity includes the image and message conveyed, as well as the communicated visuals like logos, colors, and fonts. The key to sending the right message about the brand and the first step toward creating an emotional connection with the audience is to make sure the brand personality, colors, and typography all support each other, make sense, and tell a clear story. Before building the brand personality profile, I developed a couple of target audience profiles for an effective assessment by considering the product and service offerings, and the people most interested in those offerings.
Design Deliverables
- - Color Scheme
- - Typescale
- - Collection of Brand Images
- - Mission Statement
- - Logo
- - Icon Pair
- - Social Media Header
- - Style Guide
Mission and Creative Brief
Composing a mission statement took some exploring of what exactly The Whole Bean does, understanding the target audience, the reason for the service provided and how to best serve, the purpose for being in the industry, why the business was started, and the desired brand image to convey. From these details the brand purpose was summarized into a simple mission statement: “To nourish and inspire the body and mind.”
The creative brief helped to organize the scope of the project and also acted as a planning tool by describing the goals and purpose, outlining the audience, budget, expectations surrounding deadlines, and to clarify details prior to project work. It included the overall project scope, specific goals and objectives, general client and target audience information, look and feel, strategy, deliverables, and other important details.
Holistic Identity Design
After the preliminary research, planning and structuring the main characteristics of visual branding, it was time to translate the brand’s personality into a clear visual identity consistent across multiple platforms. The holistic set of designs to begin working with next for The Whole Bean’s identity system would include its color scheme, typescale, logo, icons, and imagery.
Color Scheme
Reviewing general color guidelines and how to stay in touch with audience expectations, I chose to incorporate green into the color scheme with the dark chocolate brown and neutral browns to accent. Green is associated with: peaceful, growth, and health. The deep earth browns complement this and add coffee shop vibes.
Typescale
The selected typeface and font family traits to represent the brand need to match the traits of the brand and support the its message. The typeface chosen is mostly sans serif with clean edges, modern style, and stability, that works with an interesting display font that exudes friendliness and uniqueness.
Logo & Icon Design
An effective logo needs to blend seamlessly into a holistic identity system. Features of effective logos include simplicity, being memorable, and versatility across platforms. A logo should capture attention, engage the audience, and even create customer loyalty.
I began design of the logo by brainstorming keywords for the brand personality, grouping them into categories, viewing representative images, and then hand drawing some rough sketches for the logo concept. Finally, I cleaned up my logo sketches into some final variations to begin digital logo design.
Visual Messaging
Designs likes graphics, icons, or images can communicate ideas, messages, and feelings through their visual elements. This visual messaging of ideas can create a stronger emotional connection with the audience, giving the brand more credibility by making it seem recognizable and inspiring feelings of trust.
The imagery should evoke vibes consistent with the brand aspects: friendly, peaceful, healthy, welcoming, convey comfort. The tone of voice should support adjacent content: sincere, kind, healthy, warm. For the audience response I want to build trust and loyalty, for them to feel welcome, comfortable, safe, healthy, alive, nourished, and embraced by compassion. The composition should be clear and Images should complement the brand's logo, color scheme, and typography.
Social media interaction provides a huge opportunity for building brand recognition and connecting with the target audience, as well as building trust. The social media headers designed also need to match the brand's personality, keeping in mind the look and feel.
Completion of Style Guide
The Whole Bean is a cozy coffee shop with mellow vibes in a harmonious community neighborhood. The holistic set of identity designs created echo the the brand’s personality and compose the brand’s identity system of representative elements. Everything from its mission, to color scheme, to logo should deliver a consistent message and work together seamlessly with the brand’s image and voice.
View the full brand style guide:
Next Steps
With the company’s brand built from scratch and a holistic identity design created, Karla is planning the grand opening of her coffee shop. In anticipation, the next project lined up is to design a web landing page. The branding concept is ready to be transformed into a digital reality and The Whole Bean is getting ready to launch.


A group of CS student from the Chinese University of Hong Kong.
Mike ShumLeo SoKeith SuenEric ChanEva Yau


Index
Division I
Division II
Division III
Studio Art
Economics
Computer Science
Politics
Mathematics


--Table of Contents--
1.1 Definition of Terms
1.2 Important Points to Remember
2.1 Starting a New Class
2.2 Continuing a Previously Held Class
3.1 Adding a Schedule
3.2 Canceling a Schedule
4.1 What is Conversion?
4.2 What is a successful class?
5.1 How to Access the Materials or Lessons


I am invalid because I am not a form or input.
I am also invalid, even though I contain a form with inputs.
I am valid. I am a form that contains inputs.


Created by Mikhail Vnukov
Git is a distributed version control and source code management (SCM) system width an emphasis on speed.
Slides can be nested inside of other slides, try pressing down.
Press down or up to navigate.
Cornify
git config --global alias.lg "log --color --graph --pretty=format:
'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>
%Creset‘ −−abbrev-commit"
* dd20480 - (HEAD, rightReduce) Right reduce (4 months ago) <Mikhail Vnukov>
* 9240e3e - (origin/threads, threads) Initial thread api (4 months ago) <Mikhail Vnukov>
* a3d7294 - (master) Merge pull request #2 from alexogar/generate_$_feature (4 months ago) <Mikhail>
|\
| * 4e63749 - Generate main $ file from @IncludeInMain annotated static methods (4 months ago) <alexogar>
|/
* 8875951 - Some minor functions (4 months ago) <alexogar>
* ad4c3ef - Each with next, filter and find (4 months ago) <alexogar>
* 3bdee79 - Reduce with memo (4 months ago) <alexogar>
https://github.com/github/gitignore
Grab all suitable and put into your .gitignore
files
$ git clone https://your.repo/path
↓
Create _netrc
file in your $HOME
directory
machine <hostname> login <username> password <password>
Insecure! There are better ways
$ git clone ssh://your.repo/path
Follow your repo instructions on installing SSH keys
HEAD config description hooks index info objects refs
[hh git-basics :) ]$ ls .git/objects/
02 15 25 35 41 50 62 6b 72 80 89 96 a3 af bc c8 de f4 fd
04 17 26 36 42 55 63 6c 73 82 8a 9a a6 b0 c0 ca e0 f6 ff
05 1d 29 3c 44 59 67 6e 77 84 90 9d a7 b6 c2 cc e1 f8 info
11 20 2d 3f 47 5a 68 6f 78 87 93 9e ad b8 c3 d0 e6 f9 pack
12 24 2e 40 49 5d 69 71 7e 88 95 9f ae b9 c4 d1 e9 fa
[hh git-basics :( ]$ ls .git/objects/3c/ cf65ae409bb502812244a3a4585ae32bc9fb7d
[hh reveal.js :) ]$ git lg
* 774b933 - (HEAD, master) First steps (16 minutes ago) <Mikhail Vnukov>
* 8831469 - Initial (11 hours ago) <Mikhail Vnukov>
[hh reveal.js :) ]$ git cat-file -t 774b933
commit
[hh reveal.js :) ]$ git cat-file -p 774b933
tree 3ccf65ae409bb502812244a3a4585ae32bc9fb7d
parent<PHONE_NUMBER>13919dd3d8f35728d05e42fd070a62
author Mikhail Vnukov<EMAIL_ADDRESS>1372653800 +0400
committer Mikhail Vnukov<EMAIL_ADDRESS>1372653800 +0400
First steps
[hh reveal.js :) ]$ git cat-file -p 3ccf65ae409bb502812244a
100644 blob 9ffdbc7345be803854e777dd7183dbe76153ae47 .gitignore
100644 blob 2d6cd8f4f425afc2f026172851b172151b9f8f3e .travis.yml
100644 blob 892469a4e40641af1bf57d292a71e5c28b7373a7 Gruntfile.js
100644 blob e1e8bf7a8c29fe02e278aba9f7c5658e3b474590 LICENSE
100644 blob 96b7c0e966f4ffe7ad188b82d7ae9c5caaf42a06 README.md
040000 tree 6814ad1c3d2a3b8eb087d017a8c00a7c26c370cd css
100644 blob 02f8e62584213205a025a0ebfeaf20eca0dbcf92 index.html
040000 tree f6ddefee310758a129784ff5d68e1c7085041538 js
040000 tree a630c3d86f33c9b73712c74c2e8c602e5b884f3c lib
100644 blob c2e6d3da8f7d84db93aae4daca467f9b34eb3b2f package.json
040000 tree 0595ca9d9b4cd568541583bf15c3b595ddc43779 plugin
100644 blob bc6197e3dc1e19ec90ae353d142b177e37a89864 reveal.sublime-project
040000 tree b9c5bb7ed230640cdf846c30b06c23c692f24d44 test
[hh git-basics :) ]$ ls .git/refs
heads remotes tags
[hh git-basics :) ]$ ls .git/refs/heads/
gh-pages master
[hh git-basics :) ]$ git branch
* gh-pages
master
[hh git-basics :) ]$ ls .git/refs/remotes/origin/
gh-pages
[hh git-basics :( ]$ git branch -a
* gh-pages
master
remotes/origin/gh-pages
[hh git-basics :) ]$ cat .git/HEAD
ref: refs/heads/gh-pages
Branches are just references to commits.
[hh git-basics :) ]$ git checkout -b part2
[hh git-basics :) ]$ git checkout -b abstractions
[hh git-basics :) ]$ git commit -am "Started abstractions chapter"
[hh git-basics :) ]$ git checkout part2
[hh git-basics :) ]$ git commit -am "Added funny image to the chapter2"
Remote branches are references to the state of branches on your remote repositories. They’re local branches that you can’t move
You can select from different transitions, like:
Cube -
Page -
Concave -
Zoom -
Linear -
Fade -
None -
Default
Reveal.js comes with a few themes built in:
Sky -
Beige -
Simple -
Serif -
Night -
Default
* Theme demos are loaded after the presentation which leads to flicker. In production you should load your theme in the
using a <link>
.
Set data-state="something"
on a slide and "something"
will be added as a class to the document element when the slide is open.
Additionally custom events can be triggered on a per slide basis by binding to the data-state
name.
Reveal.addEventListener( 'customevent', function() {
console.log( '"customevent" has fired' );
} );
Set data-background="#007777"
on a slide to change the full page background to the given color. All CSS color formats are supported.

Pass reveal.js the backgroundTransition: 'slide'
config argument to make backgrounds slide rather than fade.
You can override background transitions per slide by using data-background-transition="slide"
.
These guys come in two forms, inline:
“The nice thing about standards is that there are so many to choose from”
and block:
“For years there has been a theory that millions of monkeys typing at random on millions of typewriters would reproduce the entire works of Shakespeare. The Internet has proven this theory to be untrue.”
function linkify( selector ) {
if( supports3DTransforms ) {
var nodes = document.querySelectorAll( selector );
for( var i = 0, len = nodes.length; i < len; i++ ) {
var node = nodes[i];
if( !node.className ) ) {
node.className += ' roll';
}
};
}
}
Courtesy of highlight.js.
You can link between slides internally, like this.
Hit the next arrow...
... to step through ...
any type
There's a few styles of fragments, like:
grow
shrink
roll-in
fade-out
highlight-red
highlight-green
highlight-blue
Presentations can be exported to PDF, below is an example that's been uploaded to SlideShare.
Press b or period on your keyboard to enter the 'paused' mode. This mode is helpful when you want to take distracting slides off the screen during a presentation.


Data Table Pagination
- This help users to show pagination options in the data table.
- To enable pagination it is required to set the pageable property into true.
- If the value if not specified for the above property pagination will not be shown to the user.
- When the pagination is enabled users can specify the number of items to be shown in a specific page, by using
the
limit text box.
- Users can use the navigation arrows in the pagination bar to navigate to the other pages if there are more
pages.
Suggested Links
API Doc for Data Table
Pagination