Arghya Nayek
Department:Information Technology
College Name:Government College of Engineering and Textile Technology,Serampore
Shritama Ghosh
Department:Electronics and Communication Engineering
College Name:Ramkrishna Mahato Government Engineering College(Earlier name Purulia Government Engineering College)
Mr.Asit Deva
Mr.Hemant Baid
Mr.Soumen De
MR. Raveendran Vasudevan
Year:2020
The Internship opportunity I have with Siemens was a great chance for learning and professional developement. Therefore I consider myself a very happy individualas I was provided with an opportunity to be a part of it.I am also grateful for having a chance to meet so many wonderful people and personalities who helped me enough who help me through this internship period.
I would like to express my sincere gratitude to my supervisors Mr. Asit Deva , Mr. Hemant Baid, Mr. Soumen De , Mr.Raveendran Vasudevan for providing their invaluable guidance, comments and suggestions throughout the course of the project.
I would specially thank Mr. Asit Deva for constantly motivating me to work harder and for referring the required lessons and suggestions and Mr. Hemant Baid for providing me an overview of the documentation and other necessary details.
Also I would like to thank Mr. Soumen De for his assistance and Mr. Raveendran Vasudevan for his help during the preparation of the project. My sincere thanks also go to all the representatives of Siemens Scholarship Program for their kind cooperation in all spheres during my project work.
Last but not the least, I thank my parents and all my family members for their support and motivation they have provided throughout my project work.
We declare that this written submission represents our ideas in our own words and where others' ideas or words have been included, We have adequately cited and referenced the original sources. We also declare that we have adhered to all principles of academic honesty and integrity and have not misrepresented or fabricated or falsified any idea/data/fact/source in my submission.We understand that any violation of the above will be cause for disciplinary action and can also evoke penal action from the sources which have thus not been properly cited or from whom proper permission has not been taken when needed.
I have tried my best to make the complicated process of Online Hotel Management System as simple as possible using Structured & Modular technique & Menu oriented interface. I have tried to design the software in such a way that user may not have any difficulty in using this package & further expansion is possible without much effort. Even though I cannot claim that this work to be entirely exhaustive, the main purpose of my exercise is perform each Employee’s activity in computerized way rather than manually which is time consuming.
I am confident that this software package can be readily used by non-programmingpersonal avoiding human handled chance of error. This project is used by two types of users.
i. Online Users. ii. Administrator (management of the Hotel). Online users can see the required articles or news
Administrator can maintain daily updates in the hotel records. Administrator is must be an authorized user. He can further change the password. There is the facility for passwordrecovery, logout etc. The main aim of the entire activity is to automate the process of day to day activities of Hotel like Room activities, Admission of a New Customer, Assign a room according to customer’s demand, checkout of a computer and releasing the room etc.
The limited time and resources have restricted us to incorporate, in this project, only a main activities that are performed in a HOTEL Management System, but utmost care has been taken to make the system efficient and user friendly.
“HOTEL Management System” has been designed to computerized the following functions that are performed by the system:
The project hotel management system is a web based application that allows the hotel manager(Admin Corner) to handle all hotel activities online. Interactive GUI and the ability to manage various hotel bookings and rooms make this system very flexible and convenient. The hotel manager is a very busy person and does not have the time to sit and manage the entire activities manually on paper. This application gives him the power and flexibility to manage the entire system from a single online system. Hotel management project provides room booking, staff management and other necessary hotel management features. The system allows the manager to post available rooms in the system. Customers can view and book room online. Admin has the power of either approving or disapproving the customer's booking request. Other hotel services can also be viewed by the customers and can book them too. The system is hence useful for both customers and managers to portably manage the hotel activities.
During the past several decades personnel function has been transformed from a relatively obscure record keeping staff to central and top level management function. There are many factors that have influenced this transformation like technological advances, professionalism, and general recognition of human beings as most important resources.
A computer based management system is designed to handle all the primary information required to calculate monthly statements. Separate database is maintained to handle all the details required for the correct statement calculation and generation.
This project intends to introduce more user friendliness in the various activities such as record updation, maintenance, and searching.
The searching of record has been made quite simple as all the details of the customer can be obtained by simply keying in the identification of that customer.
Similarly, record maintenance and updation can also be accomplished by using the identification of the customer with all the details being automatically generated. These details are also being promptly automatically updated in the master file thus keeping the record absolutely up-to-date.
The entire information has maintained in the database or Files and whoever wants to retrieve can’t retrieve, only authorization user can retrieve the necessary information which can be easily be accessible from the file.
The main objective of the entire activity is to automate the process of day to day activities of Hotel like:
• System Connectivity
• No data duplication • No Paper Work Required
• Time Efficient
• Cost Efficient
• Automatic data validation
• User friendly environment
• Data security and reliability
• Fast data insertion & retrieval
• Easy performance check
If any customer forget their password in login time then they click forget password button and a new page open then when customer give their emailid ,their password is shown in our website.
Any Admin to enter our website by registered email id and password to add any new hotel or remove any hotel
Any Customers who book hotels by our website frequently ,they have a unique advantage by our side.
Customers have a feedback mail after check-out from hotels to give any feedback message to us ,they log in by their registered email and password.
It has admin login who has the authority of the system and he is responsible for approving and disapproving the users request for room booking. Admin can add and delete notifications and updates in the system.
There is user registration form available where new users can create their account by providing required information to the system.
User can request for the table booking for a particular date and time.
The booking requests are directly sent with respective user details and therefore make decisions for cancelling the requests.
XAMPP is a free and open-source cross-platform web server solution stack package developed by Apache Friends, consisting mainly of the Apache HTTP Server, MariaDB database, and interpreters for scripts written in the PHP and Perl programming languages.
(Visual Studio Code is a source-code editor developed by Microsoft for Windows, Linux and macOS. It includes embedded Git and support for debugging, syntax highlighting, intelligent code completion, snippets, and code refactoring.)
(graphical web browsers developed by Microsoft and included in the Microsoft Windows line of operating systems)
(Hypertext Markup Language is the standard markup language for documents designed to be displayed in a web browser)
(Cascading Style Sheets is a style sheet language used for describing the presentation of a document written in a markup language like HTML)
(JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled programming language with first-class functions. While it is most well-known as the scripting language for Web pages)
(PHP is a widely used server-side programming language that’s become increasingly fast and powerful over the years. PHP works well with HTML and databases, making it a great language for anyone interested in building dynamic web applications.)
(Mysql is a standard language for storing, manipulating and retrieving data in databases.)

UI --> API : Verify User add hotel
API --> Database : Check all informations
alt Auth Passed
Database -> API: Authentication Accepted
API -> UI : Hotel adding Sucessful
UI -> Admin :Hotel adding Sucessful Prompt
else Auth Failed
Database -> API: Authentication Failure
API -> UI : Hotel adding Failed
UI -> Admin : Retry page
end
@enduml
@startuml
actor Admin #red
Admin --> UI : Open the UI
UI --> Admin : Responds back with the hotel Page
Admin --> UI : Slects Update hotel Page
UI --> Admin : Responds back with the Update hotel Page
Admin --> UI : Fills in hotel update information
UI --> API : Verify User Update hotel
API --> Database : Check all informations
alt Auth Passed
Database -> API: Authentication Accepted
API -> UI : Hotel updating Successful
UI -> Admin : Hotel updating Successful Prompt
else Auth Failed
Database -> API: Authentication Failure
API -> UI : Hotel updating Failed
UI -> Admin : Retry page
end
@enduml
@startuml
actor Admin #red
Admin --> UI : Open the UI
UI --> Admin : Responds back with the booking history Page
Admin --> UI : Slects booking history Page
UI --> Admin : Responds back with the booking history Page
Admin --> UI : Check booking hitory page
UI --> API : Verify User booking history
API --> Database : Check all informations
alt Auth Passed
Database -> API: Authentication Accepted
API -> UI : see sucessful booking history page
UI -> Admin : booking history Successful Prompt
else Auth Failed
Database -> API: Authentication Failure
API -> UI : Booking history page Failed
UI -> Admin : Retry page
end
@enduml
@startuml
actor Customer #red
Customer--> UI : Open the UI
UI --> Customer : Responds back with the check-in Page
Customer --> UI : Slects Check-in Page
UI --> Customer : Responds back with the Check-in Page
CUstomer --> UI : See check-in information
UI --> API : Verify User chek-in
API --> Database : Check all informations
alt Auth Passed
Database -> API: Authentication Accepted
API -> UI : Check-in Successful
UI -> Customer : Check-in sucessful Prompt
else Auth Failed
Database -> API: Authentication Failure
API -> UI : Check-in Failed
UI -> customer : Retry page
end
@enduml
@startuml
actor Customer #red
Customer--> UI : Open the UI
UI --> Customer : Responds back with the check-out Page
Customer --> UI : Slects Check-out Page
UI --> Customer : Responds back with the Check-out Page
CUstomer --> UI : See check-out information
UI --> API : Verify User chek-out
API --> Database : Check all informations
alt Auth Passed
Database -> API: Authentication Accepted
API -> UI : Check-out Successful
UI -> Customer : Check-out sucessful Prompt
else Auth Failed
Database -> API: Authentication Failure
API -> UI : Check-out Failed
UI -> Customer : Retry page
end
@enduml
@startuml
actor Customer #red
Customer--> UI : Open the UI
UI --> Customer : Responds back with the Unique advantage Page
Customer --> UI : Slects Unique-Advantage Page
UI --> Customer : Responds back with the Unique Advantage Page
CUstomer --> UI : Check unique advantage information
UI --> API : Verify User booking details
API --> Database : Check user booking either frequently or usually
alt Auth Passed
Database -> API: Authentication Accepted
API -> UI : Unique advantage Successful
UI -> Customer : Unique advantage sucessful Prompt
else Auth Failed
Database -> API: Authentication Failure
API -> UI : Unique advantage Failed
UI -> Customer : Retry page
end
@enduml
@startuml
start
:User Inputs Login details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:Login Successful;
else
:Login Failed;
endif
stop
@enduml
@startuml
start
:User Inputs Sign-up details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:Sign-up Successful;
else
:Sign-up Failed;
endif
stop
@enduml
@startuml
start
:User Inputs Logout details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:Logout Successful;
else
:Logout Failed;
endif
stop
@enduml
@startuml
start
:User Inputs booking details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:booking Successful;
else
:booking Failed;
endif
stop
@enduml
@startuml
start
:User Inputs bookig details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:booking cancelling Successful;
else
:booking cancelling Failed;
endif
stop
@enduml
@startuml
start
:User Inputs booking details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:booking updation Successfull;
else
:booking updation Failed;
endif
stop
@enduml
@startuml
start
:User Inputs email details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:showing password;
else
:password showing Failed;
endif
stop
@enduml
@startuml
start
:User Inputs add hotel details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:Add hotel Successful;
else
:Add hotel Failed;
endif
stop
@enduml
@startuml
start
:User Inputs update hotel details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:Hotel updation Successful;
else
:Hotel updation Failed;
endif
stop
@enduml
@startuml
start
:User Inputs booking history details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:booking history Successful;
else
:booking history Failed;
endif
stop
@enduml
@startuml
start
:User Inputs check-in details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:check-in Successful;
else
:check-in Failed;
endif
stop
@enduml
@startuml
start
:User Inputs check-out details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:check-out Successful;
else
:check-out Failed;
endif
stop
@enduml
@startuml
start
:User Inputs select Quarentine center details;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:Add hotel as Quarentine center Successful;
else
:Add hotel as Quarentine center Failed;
endif
stop
@enduml
@startuml
start
:User Inputs check-out details and send a feedback mail;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:send feedback mail Successful;
else
:send feedback mail Failed;
endif
stop
@enduml
@startuml
start
:User Inputs booking history details and frequent customer has unique advantage;
:API Server Recives information;
if (Database Approves) then (Approve Authentication)
:unique advantage Successful;
else
:unique advantage Failed;
endif
stop
@enduml
component as [Hotel-Mangement-UI]
component as [Hotel-Mangement-API]
@startuml
:Customer;
fork
:New Customer in our System;
:Sign-up;
:Searching hotels;
:Create-booking;
:go to booking-history page;
:log-out;
stop
fork again
:Already a customer in our system;
:Log-in;
fork
:Searching hotels;
:Create-booking;
:go to booking-history page;
:log-out;
stop
fork again
:cancel booking;
:booking-history page;
:booking-cancelled;
:booking-history page;
:log-out;
stop
fork again
:update booking;
:booking history page;
:booking-updated;
:log-out;
stop
fork again
:forget password;
: go to forget-password page;
:give registered emailid;
:show password;
stop
@enduml
@startuml
:Admin;
fork
:New Admin in our System;
:Sign-up;
:Add hotels;
:give informations;
:Hotel Added;
:log-out;
stop
fork again
:Already an Admin in our system;
:Log-in;
fork
:Add hotels;
:Give information;
:Hotel Added;
:log-out;
stop
fork again
:Update hotel
:give information;
:Hotel updated;
:log-out;
stop
fork again
:booking history page;
:log-out;
stop
@enduml
A User, who is a normal customer for the Hotel Management system that we are creating should be allowed to create a unique session upon Login. If a customer does not have an account on the system, then he should be allowed to sign up with his own unique email id which has used for registration previously. He should add the details requested along with a valid 10 digit mobile number and a password that is Alphanumeric and contains atleast 8 letters, a special character and 3 digits.
A User, who is a normal Admin for the Hotel Management system that we are creating should be allowed to create a unique session upon Login. If a customer does not have an account on the system, then he should be allowed to sign up with his own unique email id which has used for registration previously. He should add the details requested along with a valid 10 digit mobile number and a password that is Alphanumeric and contains atleast 8 letters, a special character and 3 digits.
A User, who is a customer for the Hotel Management system want to logout from our website simply click on logout button , a message is shown in our website he is logged-out sucessfully. Then ,when he can book any hotel through our website in future, he must be signup in our website as above mentioned process ,it is mandatory for all customer.
A User, who is an Admin for the Hotel Management system want to logout from our website simply click on logout button , a message is shown in our website he is logged-out sucessfully. Then ,when he can book any hotel through our website in future, he must be signup in our website as above mentioned signuprocess ,it is mandatory for all customer.
A User, who is a customer for the Hotel Management system want to book a hotel in any place,at first he can choice any hotel, if he founds a Quarentine center then it is avaliable in our aystem also.He choices a hotel and sees the hotel rent per day then goes to the create booking page and fills the all necessary informations, he adds his name, registered emailid,contact number etc and books a hotel sucessfully.After,he wants to update his booking (change hotel,change booking date etc)simply goes to the update booking page and then fills all informations or change some information and updates booking sucessfully.The Customrer somehow wants to cancel his booking goes to the cancel booking page and simply clicks on cancel booking link and a message is shown in our website and then checks the booking history page to see there must be no booking is avaliable there.
A User, who is an Admin for the Hotel Management system want to add a hotel in any place,at first he wants to add any hotel, if he adds this hotel as a Quarentine center then selects the option Quarentine center .He adds a hotel and also add the hotel rent per day then goes to the add hotel page and fills the all necessary informations, he adds his name, registered emailid,contact number etc and adds a hotel sucessfully.After,he wants to update his hotel or add some new hotel(change hotel,change anything etc)simply goes to the update hotel page and then fills all informations or change some information and updates hotel sucessfully.The Admin always sees the customer's booking history to go to the booking history page to manage his hotel's room free in customer's check-in time and also gave reminder to customer in his check-out time.
Check-in is used to admit a customer in our Hotel after entering his all personal details like Name, Address, Phone, Sex and then he/she is assigned a room.Check-out is used to checkout the customer details from database. When the user inputs his room number, the same room number will be checked in the database, if the room number is matched in the database, then the customer will be check-out from the database and transferred the record of the checkout to another table of database so that the Hotel Management has the record of customers who have check-out to fulfill his legal liabilities.
A User, who is a customer for the Hotel Management system want to see list of avaliable hotels in different cities,different places simply go to our hotel front page and choose any place as his wish,there many places hotels are avaliable and see all hotels images,name,rent per day ,and also see the hotel is either Quarentine center or not.
Any Customers who book hotels by our website frequently ,they have a unique advantage by our side. A customer who books our hotel 5th times,when he books hotel at 6th times ,he gets 5% discount from our side and also a customer who books our hotel 10th times,when he books hotel at 11th times ,he gets 15% discount from our side.
Customers have a feedback mail after check-out from hotels to give any feedback message to us ,they log in by their registered email and password and give messages how is the food,how our services write through feedback page to us.
When any customer check-out, his/her bill is generated automatically by calculated check-out date minus check-in date and getting multiplied it by daily room charge plus other charges and the bill has to be saved in the table in the database.
Now a days hotel are providing many other facilities, this project can also be improved with the improvement in the Hotels.Utmost care and back-up procedures must be established to ensure 100% successful implementation of the computerized banking system. In case of system failure, the organization should be in a position to process the transaction with another organization or if the worst comes to the worst, it should be in a position to complete it manually
This project is designed to meet the requirements of Online Hotel Managent System. For designing the system we have used simple diagrams. overall the project teaches us the essential skills like: Using system analysis and design techniques like usercase diagramagram ,sequence diagram,Activity Diagram etc in designing the system. Understanding the database handling and query processing


| Modifier and Type | Method and Description |
|---|---|
protected static void |
PolicyUtils.followAndRecordPolicy(Policy p,
Environment env,
Episode ea)
Follows this policy for one time step in the provided
Environment and
records the interaction in the provided Episode object. |
static Episode |
PolicyUtils.rollout(Policy p,
Environment env)
Follows the policy in the given
Environment . |
static Episode |
PolicyUtils.rollout(Policy p,
Environment env,
int numSteps)
Follows the policy in the given
Environment . |
| Modifier and Type | Field and Description |
|---|---|
protected Environment |
LearningAlgorithmExperimenter.testEnvironment
The test
Environment in which experiments will be performed. |
| Modifier and Type | Method and Description |
|---|---|
void |
PerformancePlotter.observeEnvironmentReset(Environment resetEnvironment) |
| Constructor and Description |
|---|
LearningAlgorithmExperimenter(Environment testEnvironment,
int nTrials,
int trialLength,
LearningAgentFactory... agentFactories)
Initializes.
|
| Modifier and Type | Class and Description |
|---|---|
class |
RLGlueAgent
An RLGlue Agent that is implemented as a BURLAP
Environment , so that
any BURLAP RL agent can control the RLGlue agent. |
| Modifier and Type | Method and Description |
|---|---|
Episode |
LearningAgent.runLearningEpisode(Environment env) |
Episode |
LearningAgent.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
Episode |
ActorCritic.runLearningEpisode(Environment env) |
Episode |
ActorCritic.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
abstract SARSData |
SARSCollector.collectDataFrom(Environment env,
int maxSteps,
SARSData intoDataset)
Collects data from an
Environment 's current state until either the maximum
number of steps is taken or a terminal state is reached. |
SARSData |
SARSCollector.UniformRandomSARSCollector.collectDataFrom(Environment env,
int maxSteps,
SARSData intoDataset) |
SARSData |
SARSCollector.collectNInstances(Environment env,
int nSamples,
int maxEpisodeSteps,
SARSData intoDataset)
Collects nSamples of SARS tuples from an
Environment and returns it in a SARSData object. |
Episode |
LSPI.runLearningEpisode(Environment env) |
Episode |
LSPI.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
Episode |
ARTDP.runLearningEpisode(Environment env) |
Episode |
ARTDP.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
Episode |
PotentialShapedRMax.runLearningEpisode(Environment env) |
Episode |
PotentialShapedRMax.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
Episode |
QLearning.runLearningEpisode(Environment env) |
Episode |
SarsaLam.runLearningEpisode(Environment env,
int maxSteps) |
Episode |
QLearning.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
Episode |
GradientDescentSarsaLam.runLearningEpisode(Environment env) |
Episode |
ApproximateQLearning.runLearningEpisode(Environment env) |
Episode |
GradientDescentSarsaLam.runLearningEpisode(Environment env,
int maxSteps) |
Episode |
ApproximateQLearning.runLearningEpisode(Environment env,
int maxSteps) |
| Modifier and Type | Method and Description |
|---|---|
EnvironmentOptionOutcome |
SubgoalOption.control(Environment env,
double discount) |
EnvironmentOptionOutcome |
Option.control(Environment env,
double discount) |
EnvironmentOptionOutcome |
MacroAction.control(Environment env,
double discount) |
static EnvironmentOptionOutcome |
Option.Helper.control(Option o,
Environment env,
double discount) |
| Constructor and Description |
|---|
BeliefPolicyAgent(PODomain domain,
Environment environment,
Policy policy)
Initializes.
|
| Modifier and Type | Class and Description |
|---|---|
class |
LearningAgentToSGAgentInterface
A stochastic games
SGAgent that takes as input a single agent LearningAgent
to handle behavior. |
| Modifier and Type | Method and Description |
|---|---|
void |
VisualActionObserver.observeEnvironmentReset(Environment resetEnvironment) |
| Modifier and Type | Class and Description |
|---|---|
class |
SimulatedEnvironment
An
Environment that simulates interactions using a SampleModel that is provided
in an input domain. |
| Modifier and Type | Interface and Description |
|---|---|
interface |
EnvironmentDelegation
Provides an interface for an
Environment that delegates its responsibilities to another Environment |
interface |
EnvironmentServerInterface
An interface for
Environment implementations that also can serve EnvironmentObserver instances
about the interactions in the Environment . |
interface |
StateSettableEnvironment
An interface to be used with
Environment instances that allows
the environment to have its set set to a client specified state. |
| Modifier and Type | Class and Description |
|---|---|
class |
EnvironmentServer
A
EnvironmentServerInterface implementation that delegates all Environment interactions and request
to a provided Environment delegate. |
static class |
EnvironmentServer.StateSettableEnvironmentServer |
| Modifier and Type | Field and Description |
|---|---|
protected Environment |
EnvironmentServer.delegate
the
Environment delegate that handles all primary Environment
functionality. |
| Modifier and Type | Method and Description |
|---|---|
static Environment |
EnvironmentDelegation.Helper.getDelegateImplementing(Environment env,
Class<?> type)
Returns the
Environment or Environment
delegate that implements the class/interface type, or null if none do. |
Environment |
EnvironmentServer.getEnvironmentDelegate()
Returns the
Environment delegate that handles all Environment
functionality |
Environment |
EnvironmentDelegation.getEnvironmentDelegate()
Returns the
Environment delegate that handles Environment
functionality |
static Environment |
EnvironmentDelegation.Helper.getRootEnvironmentDelegate(EnvironmentDelegation env)
Returns the root
Environment delegate. |
| Modifier and Type | Method and Description |
|---|---|
static EnvironmentServer |
EnvironmentServer.constructor(Environment delegate,
EnvironmentObserver... observers)
Constructs an
EnvironmentServer or EnvironmentServer.StateSettableEnvironmentServer ,
based on whether the input delegate implements StateSettableEnvironment . |
static EnvironmentServerInterface |
EnvironmentServer.constructServerOrAddObservers(Environment env,
EnvironmentObserver... observers)
If the input
Environment is an instance EnvironmentServerInterface ,
then all the input observers are added to it and it is returned. |
static Environment |
EnvironmentDelegation.Helper.getDelegateImplementing(Environment env,
Class<?> type)
Returns the
Environment or Environment
delegate that implements the class/interface type, or null if none do. |
void |
EnvironmentObserver.observeEnvironmentReset(Environment resetEnvironment)
This method is called every time an
Environment is reset (has the resetEnvironment() method called). |
void |
EnvironmentServer.setEnvironmentDelegate(Environment delegate)
Sets the
Environment delegate that handles all Environment functionality |
void |
EnvironmentDelegation.setEnvironmentDelegate(Environment delegate)
Sets the
Environment delegate that handles Environment functionality |
| Constructor and Description |
|---|
EnvironmentServer(Environment delegate,
EnvironmentObserver... observers) |
| Modifier and Type | Class and Description |
|---|---|
class |
SimulatedPOEnvironment
An
Environment specifically for simulating interaction with a POMDP
environments (PODomain ). |
| Modifier and Type | Field and Description |
|---|---|
protected Environment |
BeliefAgent.environment
The POMDP environment.
|
| Modifier and Type | Method and Description |
|---|---|
void |
BeliefAgent.setEnvironment(Environment environment)
Sets the POMDP environment
|
| Constructor and Description |
|---|
BeliefAgent(PODomain poDomain,
Environment environment)
Initializes.
|
| Modifier and Type | Field and Description |
|---|---|
protected Environment |
EnvironmentShell.env |
| Modifier and Type | Method and Description |
|---|---|
Environment |
EnvironmentShell.getEnv() |
| Modifier and Type | Method and Description |
|---|---|
void |
EnvironmentShell.setEnv(Environment env) |
| Constructor and Description |
|---|
EnvironmentShell(Domain domain,
Environment env)
Creates shell for std in and std out.
|
EnvironmentShell(Domain domain,
Environment env,
InputStream is,
PrintStream os) |
| Modifier and Type | Method and Description |
|---|---|
void |
EpisodeRecordingCommands.observeEnvironmentReset(Environment resetEnvironment) |
| Modifier and Type | Field and Description |
|---|---|
protected Environment |
VisualExplorer.env |
| Modifier and Type | Method and Description |
|---|---|
protected void |
VisualExplorer.init(SADomain domain,
Environment env,
Visualizer painter,
int w,
int h) |
| Constructor and Description |
|---|
VisualExplorer(SADomain domain,
Environment env,
Visualizer painter)
Initializes with a visualization canvas size set to 800x800.
|
VisualExplorer(SADomain domain,
Environment env,
Visualizer painter,
int w,
int h)
Initializes.
|
Copyright © 2019. All rights reserved.


| DOSE: |
220 mg |
oral |
DXM |
|
| |
20 mg |
oral |
AMT |
(powder / crystals) |
| |
20 mg |
insufflated |
AMT |
(powder / crystals) |
It is 4:36pm. I just dosed about 15 minutes ago. 20mg amt orally and 10mg amt snorted. Mild visuals.
It's now 7:20pm. it appears as though it's been 3 hours. Mild visuals. good tracers. hard to concentrate on spelling. have snorted about another 10mg. its all good. Very pleasant happy body high.
It's 2:55pm(next day) - woke up at about 1:45 this afternoon. Had a very good time last night. At about 3:30am I went to bed and lay there contemplating my existence and realizing my perma-fry insanity caused by salvia.  I always say this and never really understood why it makes me feel good. Last night AMT helped me realize that I have programmed myself to believe that 'it' - being my subjective reality at that moment which is always changing now - really is 'all good.' A
Finally fell asleep around 8am. Throughout the night I took 220mg of DXM as well as another 10mg-ish line of AMT. I noticed that the AMT masked the effects of DXM and just made for a pleasant night. I would describe this drug as 'slightly psychedelic, very happy happy happy, functional, empathic, speedy but mellow calm acid.' I would also describe it as 'emotionally hallucinogenic.' The visuals were great in the dark or with my eyes closed however they were mellow enough in the light with my eyes open that I could still easily function in society.
I believe that as that entire afternoon and evening was beautifully gleeful. Smiles and great conversation as well as admiring visuals filled my night. The conversation was at great as meth conversation but not as sporadic and unfocused or tweeked. Anyway overall experience was superb. This was my second experience with AMT. Looking around I am still noticing very very mellow tracers and auras around lights.
Experience Reports are the writings and opinions of the individual authors who submit them.
Some of the activities described are dangerous and/or illegal and none are recommended by Erowid.


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Posted on 06/03/2018 at 08:30 AM by The Vibe.
Starting the clinical procedure of looking for Internship as a student of one of the highly reputed Institutes in the country, I thought that it would be a cake walk. And you guessed it right - I was SO naive and wrong. Read through a story of multiple rejections, followed by an all-is-well-that-ends-well ending. Also, I really hope that this blog post can instill people going through a similar phase with motivation.
I'm a 4th year undergrad from IIT Kharagpur. I've been into programming right from my first year, when I started with web development. Then came the exposure to the realm of open-source and the steep learning curve along with it. You can have a look at my Resume for the long story. But in short, I'm really passionate about software development and have a knack for the same.
I'm from the Department of Mechanical Engineering. What that means, is that I won't be allowed to even sit for most of the software companies that come to campus. That includes companies like Google, Microsoft, Intuit, Amazon, etc.
Also, I've observed that companies tend to recruit safely. So, any company on any given day would prefer recruiting a CS student over a Mechie for a Software Development profile. Who would take risk and make an unorthodox decision, right?
In-campus and off-campus positions.
As much as you want to get a good Internship, so are the others applying for the position. So, everyone is going to give their very best and let natural selection to do the rest. And as I've stated above, I'm from IIT Kharagpur - need I explain more about how talented the competition pool is?
(Aug 2017)
Goldman Sachs was one of the companies that came to IIT Kharagpur on day 1 of the Internship process. Being one of the very few "prestigious" companies with a software-related profile that opened for Mechanical Engineering students, I definitely applied.
All students who applied through the CDC-IITKGP website had to take an online test on HackerRank. This test included 3 parts - Coding, Machine Learning & Aptitude. There were about 15-20 MCQ questions across these 3 genres, and also 2 questions to write code.
After being shortlisted by the online test results, we had continous rounds on the same day. This first round was pretty easy - it involved me explaining the projects I had worked on, what were the difficulties I faced, how I overcame them and what were the takeaways I gathered for further projects.
Next, the interviewer asked me to solve this sum problem and another simple string manipulation question. I solved them both, and we discussed about what the interviewer's team (Security) does at Goldman Sachs. Oh, we were also able to discuss about the recent GoT episode that had aired.
With Round 1 being very satisfactory, I was passed on to Round 2. I was again asked to talk about some of my projects, though - not in such detail as the previous round. He then asked me to solve a question based on intervals. I was able to solve this, and went ahead explaining a test case. Later, he told me about the Tech stack being used in GS. We also discussed about how it becomes frustrating to manage Python codebases with teams that have different Space-Tab configurations.
After the 2nd results were out, the remaining shortlisted students were told to have lunch and come back in an hour for the final round of interview. Again, the interviewer asked me about some of the projects I had worked on. Then, he told me to solve this sum-tree question.
I made a mistake of missing out the termination criteria of the recursive algorithm, and the interviewer pointed out the same. After correcting it, we discussed more about the possible roles at GS.
I was really confident about getting the Internship, given how my interviews went. However, it came as a shock when I saw the CDC notice board later that evening and found out that my name wasn't included in the list. I pinged Hardik Sheth (one of my seniors at GS), but he wasn't able to find any feedback either. One of his messages that I'd like to quote is,
"Don't be disheartened, dedicated desperation will take you anywhere you want."
- Hardik Sheth
And yes, I maybe did cry a little. But this rejection also got me immidiately hooked on to book reading. That's a win, right?
(Sep 2017)
This was definitely an off-campus opportunity. GitHub had just posted their openings for Summer Internships of 2018. One of the roles that seemed pretty interesting to me was that of Rails Developer, and I applied on their website. A week later, one of GitHub's Talent Acquisition staff got in touch with me and we scheduled the first interview. However, as the interviewers were supposedly busy for the next 2 weeks, I had my interview scheduled after 15 days of getting in touch.
In the meantime, I also went though GitHub Classroom - the project for this role, and started contributing. However, on THE day of the interview, I received a mail saying that they've already found another Hubber who'll be working on the same project, and hence the Internship profile is not open anymore. That was literally an hour before my scheduled interview.
Apologizing for the inconvinience, GitHub sent me a few goodies - Tee & Hoodie. No one can remain upset after receiving goodies, right?
(Dec 2017)
During the winter vacations, I received a message from a DE Shaw executive on LinkedIn, informing me about a vacancy in the team and how I could be a possible fit. Being in my pre-final year, I politely rejected it and rather asked them about whether I could be considered for a Summer Internship instead. But I'm yet to get any interview scheduled.
I'm good enough to be considered for a job, but not for an internship? Sed lyf.
(Feb 2018)
Morgan Stanley came to campus in mid-Febraury 2018. The online test was quite generic, 15-20 MCQs of both coding and aptitude questions with 2 coding problems. I don't remember the questions exactly, but one of them was quite easy and the other was of intermediate difficulty.
After being shortlisted by the online test results, nearly 20 students gave this round. This round took place almost 2 weeks after the online test, and there were 3 interviewers who had come on campus.
I was called at around 10PM. The interviewer was really interesting to interact with. We discussed about some of my open-source projects, and later I was given to solve this question. I was also asked a few questions on different data structures, and it was pretty good overall.
After the 1st round, 9 students were shortlisted for this final round of interview. The interview started with me explaining my project, and the interviewer asked a question on system design. I wasn't able to explain much about the scalability, but I was able to put together the different pieces required for the question.
I was also asked to solve this dialpad problem, which I was able to do with recursion and 10 mins. Finally, we discussed about how Morgan Stanley handles scalability and what are the expectations of an Intern.
I stayed back at the Main Building to have a look at the results first-hand. The PlaceComm member (who had become my friend by the previous round) came running to me with a sad face and told me that I didn't make it. Quite frankly, I wasn't as sad. Maybe, it was just that the past rejections had trained me to cope up with upcoming rejections. Or maybe it was the free Morgan Stanley Tee that I had received in the last round. Anyways, I remember walking out of the Main Building with a grin, proud of how I took this rejection.
(Feb 2018 - Mar 2018)
Peter Thomas from Intuit, came to IIT Kharagpur to give a hands-on workshop on his open-source project (Karate) that has recently received a lot of traction. All the attendees were sponsored a free Subway snack, as well as an Intuit bag (goodie).
The interaction was really fun, with Peter giving a couple of examples of how Karate is pretty useful and also throwing a couple of life advices every now and then. At the end of the workshop, we were told that students contributing to this project would be considered for Internship opportunities at Intuit.
Being a huge open-source fan looking for internship, I couldn't think of a better opportunity. So, I started setting up the repository and contributed a few Pull Requests within the weekend.
After the Pull Requests got merged, I communicated with Zubin and Naina from Intuit about the contributions and my intent to do a Summer Internship at Intuit. At the same time, one of my seniors (Naresh) also referred me for this internship. Hence, I was scheduled an interview in a week.
The 1st round was taken by Prateek Mandloi. The interview started with my introduction, and discussion about some of my open-source contributions (including Karate).
Then, I was asked to solve a 2D-matrix related coding problem wherein there were blank spaces, and given sequence of numbers had to be inserted into appropriate positions (increasing order) in the matrix (taking the blanks into account). I was able to come up with a solution involving binary search to find out the index of insertion and also handle blank spaces. But, I made a very silly mistake in the binary search method - which Prateek pointed out later.
Further, we discussed about a few of the projects that Intuit works on, and what'll be the scope of an intern.
The 2nd round took place nearly a week after the first one, and was taken by Roshni Neogy. Overall, it was a really friendly interview - something I hadn't experienced for some time now.
I was first asked a system design question on designing an online treasure hunt for the campus. I was able to discuss the different models that would be required to build such an application. While discussing about campus-related applications, I was also able to briefly talk about the projects among other interactive sessions held by Metakgp.
Further, I was asked the difference between Queue and Stack data structure, and how to implement Queue from Stack. I was able to come up with the idea of using 2 stacks on-the-spot (thankfully!).
The final round took place a week after the second one, and was taken by Bala Dutt. First things first, I was excited because the interviewer is an alumnus of IIT Kharagpur. It was another one of those GOOD interviews that were more of a discussion, rather than a Question-Answer session.
I was asked a few theoretical questions such as virtual classes, deadlocks in parallel computation, etc. After that, we had a discussion on how to implement a data structure that would have constant time for insertion, deletion, look-ups and returning random members. The moment I heard "look-up", I was pretty sure it had to be a hashmap. I was able to implement this data structure using both Array and Hashmap, just like this.
Finally, we discussed about kind of projects I'd like to work on during the Internship (if I got one, ofcourse) and how to switch to coding when coming from a non-CS background.
On the same day as the 3rd round, I got a call from Zubin informing me that my interviews went well and Intuit will be offering me with an Internship. It was really relieving to hear this. Thanks for making an unorthodox decision by giving chance to a non-CS guy, Intuit!
"Don't be disheartened, dedicated desperation will take you anywhere you want."
- Hardik Sheth"Things work out at the end. They always do!"
- Naresh Ramesh


Provides an R interface for the Bureau of Economic Analysis (BEA) API (see <http://www.bea.gov/API/bea_web_service_api_user_guide.htm> for more information) that serves two core purposes - 1. To Extract/Transform/Load data [beaGet()] from the BEA API as R-friendly formats in the user's work space [transformation done by default in beaGet() can be modified using optional parameters; see, too, bea2List(), bea2Tab()]. 2. To enable the search of descriptive meta data [beaSearch()]. Other features of the library exist mainly as intermediate methods or are in early stages of development. Important Note - You must have an API key to use this library. Register for a key at <http://www.bea.gov/API/signup/index.cfm> .
| Version: | 1.0.6 |
| Depends: | R (≥ 3.2.1), data.table |
| Imports: | httr, DT, shiny, jsonlite, googleVis, shinydashboard, ggplot2, stringr, chron, gtable, scales, htmltools, httpuv, xtable, stringi, magrittr, htmlwidgets, Rcpp, munsell, colorspace, plyr, yaml |
| Published: | 2018-02-23 |
| Author: | Andrea Batch [aut, cre], Jeff Chen [ctb], Walt Kampas [ctb] |
| Maintainer: | Andrea Batch <Andrea.Julca at bea.gov> |
| License: | CC0 |
| URL: | https://github.com/us-bea/bea.R |
| NeedsCompilation: | no |
| CRAN checks: | bea.R results |
| Reference manual: | bea.R.pdf |
| Package source: | bea.R_1.0.6.tar.gz |
| Windows binaries: | r-devel: bea.R_1.0.6.zip, r-release: bea.R_1.0.6.zip, r-oldrel: bea.R_1.0.6.zip |
| OS X binaries: | r-release: bea.R_1.0.6.tgz, r-oldrel: bea.R_1.0.6.tgz |
| Old sources: | bea.R archive |
Please use the canonical form https://CRAN.R-project.org/package=bea.R to link to this page.


{% extends "base.html" %} {% import "bootstrap/wtf.html" as wtf %} {% block content %}
Setting goals can help to motivate us. They can remind us why we are exercising and help hold ourselves accountable.
Do you have a goal? Is there a reason for this goal and how will you reward yourself for achieving this goal?
Think about your reasons for exercising and then enter your goals below. LogMyExercise can help you track progress towards the goals
Remember goals change and you will want to review and update these every month


Enter two factors and click calculate to multiply the two numbers.
Click clear to clear the two input fields.
The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers
is defined by a systematic generalization of this basic definition.
Multiplication can also be visualized as counting objects arranged in a rectangle (for whole numbers) or as
finding the area of a rectangle whose sides have given lengths. The area of a rectangle does not depend on
which side is measured first, which illustrates the commutative property.
The inverse operation of the multiplication is the division. For example, since 4 multiplied by 3 equals 12,
then 12 divided by 3 equals 4. Multiplication by 3, followed by division by 3, yields the original number
(since the division of a number other than 0 by itself equals 1).
Multiplication is also defined for other types of numbers, such as complex numbers, and more abstract
constructs, like matrices. For these more abstract constructs, the order that the operands are multiplied
sometimes does matter.
With this multiplier (or multiplication calculator) you can calculate integers and decimals, positive and negative. The common methods for multiplying numbers using pencil and paper require a multiplication table of memorized or consulted products of small numbers (typically any two numbers from 0 to 9), however one method, the peasant multiplication algorithm, does not. Multiplying numbers to more than a couple of decimal places by hand is tedious and error prone. Common logarithms were invented to simplify such calculations. The slide rule allowed numbers to be quickly multiplied to about three places of accuracy. Beginning in the early twentieth century, mechanical calculators, such as the Marchant, automated multiplication of up to 10 digit numbers. Modern electronic computers and calculators have greatly reduced the need for multiplication by hand.
When two measurements are multiplied together the product is of a type depending on the types of the measurements. The general theory is given by dimensional analysis. This analysis is routinely applied in physics but has also found applications in finance. One can only meaningfully add or subtract quantities of the same type but can multiply or divide quantities of different types. A common example is multiplying speed by time gives distance, so 50 kilometers per hour * 3 hours = 150 kilometers. To learn more about multiplication, head over to Wikipedia.


Training a foal to replace a venerable workhorse
Return to OpenBSD
Presentations & Papers
Csikó - Foal. - Photo: Adam Tomkó @flickr (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 2: INTRO I -
BSDCan 2011, May 13, Ottawa
What for?
Formatting man(1) pages.
→ See also the companion talk by Kristaps Dzonsons,
"The roff tradition and mandoc".
$ mandoc /usr/src/share/man/man7/mdoc.7
$ man mdoc
Both commands produce:
$ man mdoc
MDOC(7) OpenBSD Reference Manual MDOC(7)
NAME
mdoc - mdoc language reference
DESCRIPTION
The mdoc language is used to format BSD UNIX manuals. This reference
document describes its syntax, structure, and usage. The reference
implementation is mandoc(1); the COMPATIBILITY section describes
compatibility with other troff -mdoc implementations.
Make documentation easily accessible:
- Have it at as few places as possible,
and as much as possible at one single place.
- In OpenBSD, almost all documentation is manuals,
and the little that doesn't fit there is all in the FAQ.
Thus, manuals are very important in OpenBSD.
Ingo Schwarze: Mandoc in OpenBSD - page 3: INTRO II -
BSDCan 2011, May 13, Ottawa
What from?
→ See also Kristaps' talk.
mdoc(7) or man(7) source files - plus roff(7), tbl(7), ...
$ less /usr/src/share/man/man7/mdoc.7
.Dd $Mdocdate: May 26 2011 $ \" rcs(1) style Mdocdate ID
.Dt MDOC 7 \" prologue: meta information
.Os
.Sh NAME
.Nm mdoc \" one word document title
.Nd mdoc language reference \" one line document description
.Sh DESCRIPTION \" section structure
The \" free text
.Nm mdoc \" logical markup
language is used to format
.Bx
.Ux
manuals.
This reference document describes its syntax, structure, and
usage.
The reference implementation is
.Xr mandoc 1 ; \" cross references to other manuals
the
.Sx COMPATIBILITY \" cross references inside one manual
section describes compatibility with other troff \-mdoc implementations.
.Pp
An
.Nm
document follows simple rules: lines beginning with the control
character
.Sq \. \" block enclosures
are parsed for macros.
Other lines are interpreted within the scope of
prior macros:
.Bd -literal -offset indent \" display blocks
\&.Sh Macro lines change control state. \" escaping
Other lines are interpreted within the current state.
.Ed
Ingo Schwarze: Mandoc in OpenBSD - page 4: INTRO III -
BSDCan 2011, May 13, Ottawa
Table of contents
- OpenBSD 4.6 - the foal's pasture
- OpenBSD 4.7 - serious training
- OpenBSD 4.8 - drawing the cart
- OpenBSD 4.9 - removing groff
- Recurring topics
- Conclusions
- Future directions
Ingo Schwarze: Mandoc in OpenBSD - page 5: Apr to Dec 2009 -
BSDCan 2011, May 13, Ottawa
Grazing the foal's pasture
Half a year free of serious responsibilities.
- Imported mandoc into the OpenBSD tree.
- Collected initial experience using mandoc.
- Main occupation during this time: Fixing bugs.
- Slowly started setting up a regression suite.
- Established the contact to everybody involved.
Related timeline:
2008 Nov 22: first commit to mdocml.bsd.lv by kristaps@
2009 Mar 27: first direct commit by schwarze@ to OpenBSD (not mandoc)
2009 Apr 06: mandoc imported into OpenBSD by kristaps@
2009 Apr 15: first help from another OpenBsd developer (miod@)
2009 May 23: schwarze@ first talks to jmc@ about mandoc
2009 May 31: at c2k9 in Edmonton, schwarze@ talks to deraadt@
2009 Jun 09: kristaps@ agrees to work closely together
2009 Jun 14: merge to OpenBSD started by schwarze@
2009 Jun 15: first patches merged back from OpenBSD to bsd.lv
2009 Jun 21: mandoc usable in OpenBSD and in sync with bsd.lv
2009 Jun 23: bugfixing in OpenBSD started by schwarze@
2009 Jul 05: OpenBSD 4.6 release rolled without mandoc
2009 Jul 12: joerg@ sends his first patch from NetBSD
2009 Jul 18: uqs@ sends his first patch from FreeBSD
2009 Oct 27: start src/regress/usr.bin/mandoc
2010 Jan 02: start of systematic integration
Ingo Schwarze: Mandoc in OpenBSD - page 6: TRAIN I -
Jan and Feb 2010 - BSDCan 2011, May 13, Ottawa
See the world!
Let mandoc build the whole tree.
Systematically investigate all fatal issues.
- Ignore all non-fatal issues for now.
- Fix the easy problems in mandoc, right away.
- Work around hard ones by changing manuals in the tree.
Most workarounds got fixed later:
- block opened, but not closed, and vice versa
- bad nesting of (full) blocks
- free-form text in context requiring macros
- blank lines outside literal context
- low-level requests not (yet) implemented in mandoc
- wrong number of arguments
- ...
Related timeline:
2010 Jan 02: first patches to mdoc(7) manuals to fix the build with mandoc
"Fine. Even if mandoc goes nowhere, it has found some bugs. ;)"
jmc@
2010 Feb 17: first patch to a man(7) manual in order to fix the build
2010 Feb 20: found first manual bug caused by DocBook
2010 Feb 24: first non-fatal manual fix found by -Tlint
2010 Feb 25: tree now builds with mandoc
2010 Mar 18: OpenBSD 4.7 release rolled without mandoc
Ingo Schwarze: Mandoc in OpenBSD - page 7: TRAIN II - Feb 2010 -
BSDCan 2011, May 13, Ottawa
Block nesting
An example of nice mandoc design
→ See also Kristaps' talk.
Example manual snippet using nested blocks:
$ mandoc chgrp.1
SYNOPSIS
chgrp [-fh] [-R [-H | -L | -P]] group file ...
The corresponding mdoc(7) source code:
$ less chgrp.1
[...]
.Sh SYNOPSIS
.Nm chgrp
.Op Fl fh
.Oo
.Fl R
.Op Fl H | L | P
.Oc
.Ar group
.Ar
[...]
Mandoc respresents this by this syntax tree:
$ mandoc -Ttree chgrp.1 # much simplified
Sh (block) SYNOPSIS
Nm (block) chgrp
Op (block)
Fl (elem) fh
Oo (block)
Fl (elem) R
Op (block)
Fl (elem) H
(text) |
Fl (elem) L
(text) |
Fl (elem) P
Ar (elem) group
Ar (elem) file ...
Traditional roff/mdoc design: no block structure!
low level: roff requests provide
- physical formatting
- registers to store data
- macro expansion
high level: mdoc macros
- call physical formatting
- set registers to keep state
- have no syntax tree
Ingo Schwarze: Mandoc in OpenBSD - page 8: TRAIN III - Feb to Jun 2010 -
BSDCan 2011, May 13, Ottawa
Blood, sweat, and tears
Badly nested blocks and the Xo macro
Explicit blocks, badly nested:
.Ao ao
.Bo bo
.No ac Ac
.No bc Bc
<ao [bo ac> bc]
Implicit block broken by explicit block:
.Aq aq Bo bo eol
.No bc Bc
<aq [bo eol> bc]
The most important case in practice: .It Xo
$ less find.1
[...]
.It Xo
.Ic -exec Ar utility
.Op argument ...
.No ;
.Xc
-exec utility [argument ...] ;
Our first thought: deprecate this abomination!
- use: .It Ic -exec Ar utility Oo argument ... Oc No ;
- but lots of manuals use ".It Xo" - historical argument limit
- no way to change all manuals, everywhere
- or even the habits of people writing manuals...
- reluctant implementation:
- Ao block contains the *whole* Bo block
- Bo block contains an Ao body-end element
All mdoc(7) manuals build at this point!
Related timeline:
2010 Feb 23 remove .Oo .Xo .Oc .Xc mis-nesting from manuals (questionable)
2010 Feb 26 support .It Xo (good)
2010 Jun 29 support badly nested blocks in general (even better)
Ingo Schwarze: Mandoc in OpenBSD - page 9: TRAIN IV - Mar 2010 -
BSDCan 2011, May 13, Ottawa
Hey, aren't you cheating?
Explicit pod2man(1) preamble support.
Example code from the standard pod2man preamble:
$ less perl.1
[...]
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
This uses low-level roff requests:
- .ds user defined strings
- .de macro definitions
- .if conditionals
- and some more...
No chance to get all that implemented quickly.
Quick and dirty solution:
- Hardcode the strings (always the same - it's a preamble).
- Implement the macros as if they were man(7) macros.
- Parse and ignore the rest.
Now all man(7) manuals build as well!
No fixes in man(7) manuals, just workarounds in mandoc.
Related timeline:
2010 Mar 01 implement pod2man(1) pseudo-macros
2010 Sep 20 mandoc can now handle the standard pod2man preamble
2010 Nov 28 remove the pod2man(1) pseudo-macros
Ingo Schwarze: Mandoc in OpenBSD - page 10: TRAIN V - conclusions -
BSDCan 2011, May 13, Ottawa
Don't be lazy.
What went wrong while getting the tree to build?
- We should have started several months earlier.
- At first, mandoc reported way too many fatal errors.
- Too few mandoc bugs were fixed in this phase.
- Too many workarounds committed to manuals instead.
Lessons learnt:
- From the start, avoid throwing fatal errors when possible.
- By all means, report errors, but try hard to keep going.
- Try real-world usage as early as possible and use the feedback.
- Move quickly into production, don't delay for polishing.
- Code will only really mature when used.
New Forest Foal. -
Photo: Krista van der Voorden <Kris*V*@flickr> (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 11: DRAW I - Apr 2010 -
BSDCan 2011, May 13, Ottawa
What are you waiting for?
Switch over the tree as soon as possible.
- Ready for production just before the 4.7 release.
- Switch over the build right after the release,
to have as much time as possible to fix fallout.
- Bug reports from real-world users come in now.
- Give priority to these bug reports.
- All serious fallout fixed very quickly - within a few days.
- Lots of time for polishing before the first release.
Related timeline:
2010 Mar 01: mandoc ready to build the tree
2010 Mar 18: OpenBSD 4.7 release rolled without mandoc
2010 Mar 20: Xenocara can now build with mandoc as well
2010 Apr 02: link mandoc to the OpenBSD build
2010 Apr 03: switch base build to mandoc, excepting tbl pages
2010 Apr 03: fix all fatal issues where mandoc kills ports builds
2010 Apr 04: first port maintainer explicitely switches to mandoc
2010 Apr 04: fix first mandoc bug that was found by ports usage
2010 Apr 05: espie@ implements USE_GROFF framework and groff-1.15 port
2010 Apr 07: first major merge from bsd.lv after the switch
2010 Apr 08: first mandoc bugfix found in ports propagates upstream
2010 Aug 12: OpenBSD 4.8 release rolled with mandoc
Photo: tiny_package @flickr (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 12: DRAW II - Apr and May 2010 -
BSDCan 2011, May 13, Ottawa
If ifs & ands were docs & mans...
No way around some low-level roff requests.
- Original design:
- Forget about the complete bottom layer.
- Only implement high-level mdoc(7) & man(7) macros.
- Didn't work out.
- Real-world manuals use some low-level requests.
- Realizing that was a slow, painful process.
- We reluctantly edged in some low-level roff support.
- Complexity was kept to the bare minimum.
- Both steps have proven to be just right:
- Starting from the high level gave a clean design.
- Roff reluctance prevented getting off track.
- Surprise: Rather little impact in the end.
Related timeline:
2010 Apr 25: implement roff conditional instructions, man(7) only
2010 May 15: mandoc roff library started by kristaps@
2010 May 19: the roff library replaces my preliminary support for conditionals
2010 Jul 03: rudimentary implementation of user-defined strings
2010 Sep 22: interesting commit message: no hope for .de
2010 Nov 25: implement the .de (define macro) roff instruction
Ingo Schwarze: Mandoc in OpenBSD - page 13: DRAW III - May 2010 -
BSDCan 2011, May 13, Ottawa
Desperation lead to success:
How an afterthought improved the design.
Original mandoc main program:
- main loop to read input files
- push line after line into the parser backends
- parsers look for high-level macros, e.g. mdoc(7)
- call the formatting frontend on the resulting syntax tree
Modified mandoc main program:
- main loop to read input files
- call the roff preprocessor on each line
- push line after line into the parser backends
- parsers look for high-level macros, e.g. mdoc(7)
- call the formatting frontend on the resulting syntax tree
Paradigmatic switch:
roff: expand high-level macros into low-level requests
- then pass the low-level requests into the formatters
- all structural info lost long before the main parser
mandoc: first handle low-level requests (preprocessor)
- then pass the high-level code to the parsers
- structural info kept even when intermixed with low-level roff
→ See Kristaps' talk for applications
Ingo Schwarze: Mandoc in OpenBSD - page 14: DRAW IV - May 2010 -
BSDCan 2011, May 13, Ottawa
.if .ds .de
Examples of roff macros we need.
- ignore:
- adjustment: .ad .ta
- spacing: .ne .ns
- hyphenation: .hy .nh
- character formatting: .ps .tr
- error out:
- partial implementation:
- conditionals: .if .ie .el
- register definitions: .nr
- complete implementation:
- string definitions: .ds
- macro definitions: .de .rm
- source file inclusion: .so
Very young zebra. - Photo: Tambako @flickr (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 15: DRAW V - Jun and Jul 2010 -
BSDCan 2011, May 13, Ottawa
Invented here.
Home-grown non-standard features even in OpenBSD.
Almost all related to SYNOPSIS formatting:
- Roff register to control SYNOPSIS mode.
- Nm indentation in SYNOPSIS mode.
- Word keeps in SYNOPSIS mode.
Quite some work to get this right,
for features of no theoretical importance
that are not even documented.
Similar stuff would probably come up
in other systems, when switching them over.
Related timeline:
2010 Jun 25 schwarze@ at the c2k10 hackathon in Edmonton
2010 Jun 26 basic implementation of .Bk/.Ek
2010 Jun 27 full .nr nS support, unbreaking the kernel manuals
2010 Jul 01 improve .Nm indentation in the SYNOPSIS
Ingo Schwarze: Mandoc in OpenBSD - page 16: DRAW VI - Summer 2010 -
BSDCan 2011, May 13, Ottawa
Count your beans.
Automatic comparisons as part of the build system.
Iterative process, several cycles:
- Run comparisons on a small part of the tree.
- Identify parsing and formatting issues.
- Prioritize by frequency and severity.
- Fix sufficiently few that you don't lose too much time.
- Fix sufficiently many to significantly reduce the noise.
- Start over with a larger part of the tree.
In parallel, tweak groff to reduce noise in comparisons:
- no adjustment
- no hyphenation
- OpenBSD headers
- no special handling of Pa in FILES
A text file in CVS was the ideal bug tracker:
- Keep the number of known issues low.
- Don't let the complexity of the backlog outgrow the complexity of the code.
Related timeline:
2010 Aug 15 systematic bug hunting in /bin and /sbin
2011 Jan 23 systematic bug hunting in /usr/bin
Ingo Schwarze: Mandoc in OpenBSD - page 17: DIGRESSIONS -
BSDCan 2011, May 13, Ottawa
All work and no play...
Nice features along the way
Critical points:
- Reliable parsing.
- Correct ASCII rendering.
However, fancy output is fun.
- We took the time now and again.
- Almost all projects went well: e.g. HTML, XHTML, PostScript, PDF
- One was overdone and a dead end: hyphenation
Related timeline:
2009 Oct 21 HTML and XHTML output modes by kristaps@
2009 Oct 24 hyphenation patch by schwarze@ (still unused)
2010 Mar 01 proper inter-sentence spacing for mdoc(7)
2010 Mar 05 at the end of lines, split words at existing hyphens
2010 Apr 22 proper tab handling
2010 Jun 10 PostScript output mode started by kristaps@
2010 Jul 31 PDF output mode completed by kristaps@
2010 Sep 09 use mandoc instead of groff to build PostScript manuals
Foals Just Wanna Have Fun. -
Photo: Gary Tanner <gazzat@flickr> (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 18: REMOVE I - early Oct 2010 -
BSDCan 2011, May 13, Ottawa
Only a dozen pages...
... are using tbl, the last obstacle to groff removal.
- We long shunned the task:
- Even though basic code was long available,
- these were very few pages,
- and it was unclear how to do it best;
- we nearly waited too long for the release.
- Finally, i deliberately chose the minimal route:
- hook the code directly into the high-level parsers
- working integration within a single weekend
- immediately rely on it for production
- Kristaps implemented a better way later:
- parse tbl block macros on the roff level
- call the parser for the content from the main program
just like in the case of mdoc(7) and man(7)
Related timeline:
2010 May: stand-alone implementation of tbl started by kristaps@
2010 Aug 12: OpenBSD 4.8 release rolled with mandoc
2010 Oct 15: import tbl parser and renderer written by kristaps@
2010 Oct 17: build tbl(1) pages with mandoc(1), not groff
2010 Oct 18: disconnect groff from the base build
2010 Oct 18: "I absolutely don't intend to merge tbl into mandoc" kristaps@
2011 Jan 04: clean tbl integration by kristaps, remove mine
Ingo Schwarze: Mandoc in OpenBSD - page 19: REMOVE II - late Oct 2010 -
BSDCan 2011, May 13, Ottawa
Not scared by one-way streets!
Groff emigrating to ports land.
- Groff and ports tree already prepared by<EMAIL_ADDRESS>- Use a groff build dependency and install formatted manuals.
- X11 manuals got briefly broken:
- Support for file inclusion (.so) arrived one week late.
- Set up instructions for checking ports.
- Start moving over ports to mandoc case by case.
- Installing source manuals.
- Bug reports from porters start flowing in.
- Again, give priority to fixing real-world issues.
Related timeline:
2010 Aug 12: OpenBSD 4.8 release rolled with mandoc
2010 Oct 18: disconnect groff from the base build
2010 Oct 19: switch default /etc/man.conf to mandoc
2010 Oct 23: schwarze@ at p2k10 hackathon in Budapest
2010 Oct 26: support .so (low-level roff "switch source file")
2010 Oct 27: OpenBSD ports FAQ section about mandoc and groff
2010 Oct 29: landry@ performs the first major USE_GROFF removal
2010 Oct 29: millert@ removes colcrt(1), checknr(1), soelim(1)
2011 Feb 07: use mandoc in Xenocara Imake builds
2011 Mar 02: OpenBSD 4.9 release rolled without groff
2011 Mar 12: cvs rm groff
Cart. - Photo: garycycles7 @flickr (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 20: CONCLUSIONS I -
BSDCan 2011, May 13, Ottawa
Done!
Reached the stage: It just works.
To get there:
- Re-implemented a small family of languages.
- Turned the whole paradigm upside down.
- Remained compatible where it matters.
- Flouted compatibility that would just hinder.
Other systems can now do the same, if they want.
- ... without much risk.
- ... without having to fear major surprises.
- ... getting support from us in case of need.
Just mail us!
Ingo Schwarze: Mandoc in OpenBSD - page 21: RECURRING I -
BSDCan 2011, May 13, Ottawa
Show what's relevant, not more.
Why it is critical to get errors and warnings right.
- An error message is missing or too generic:
- Users have a hard time to fix their errors.
- A warning message is missing:
- Users don't even notice their dangerous idioms.
- A few warnings too many, or too prominent:
- Users get annoyed and switch off all warnings.
- More than one or two knobs:
- Users don't remember and don't use them.
- Too few and too many can happen all at once!
- (It did with mandoc, and it had too many knobs - at first.)
Related timeline:
2009 Jul 12: fewer knobs: remove -Wsyntax -Wcompat
2010 May 13: fewer knobs: remove -fno-ign-chars
2010 May 23: unified error and warning system by kristaps@
2010 Aug 19: simple, consistent user interface for error handling
2010 Oct 24: do not throw fatal errors when there is no need to
2010 Oct 26: downgrade nearly 20 errors to warnings
2011 Jan 16: downgrade yet another bunch of fatal errors
2011 Jan 22: check argument count validation for all in_line() macros
Ingo Schwarze: Mandoc in OpenBSD - page 22: RECURRING II -
BSDCan 2011, May 13, Ottawa
Bogue déjà vue:
Collecting regression tests.
- Slow start in 2009:
- Many new bugs, few regressions.
- Automatic tests not a priority.
- However, start collecting anyway!
- The code matures...
- More tests show up naturally.
- They slowly become more important.
- Periodic sorting and checking in.
- Current state:
- When doing major merges,
- the suite regularly catches issues.
- The continuous effort starts to pay off.
Related timeline:
2009 Oct 27: start src/regress/usr.bin/mandoc
2010 Jun 30: major update of the mandoc test suite
2010 Jul 01: enable mandoc regression tests; ok phessler@
2010 Dec 04: major additions to the regression suite
2011 Feb 05: commit many regression tests found in my trees
Horse Fly Portrait. - Photo: Jeff Burcher <VonShawn@flickr> (CC)
Ingo Schwarze: Mandoc in OpenBSD - page 23: RECURRING III -
BSDCan 2011, May 13, Ottawa
Bad patches triggering good ones
Preliminary code put in and ripped out again.
That may seem inefficient,
but actually it's a perfectly sane approach:
- The first implementation explores the feature.
- The second implementation gets it right.
- Just don't let the first one sprawl until it can't be ripped out any more.
Related timeline:
This approach got used in at least five cases:
2010 Mar 01 - May 14: end of sentence detection
2010 Apr 25 - May 19: roff conditionals
2010 Mar 01 - Sep 20: pod2man preamble
2010 Jun 16 - Jun 27: roff registers
2010 Oct 15 - Jan 04: tbl integration
Ingo Schwarze: Mandoc in OpenBSD - page 24: CONCLUSIONS II -
BSDCan 2011, May 13, Ottawa
Newly designed.
Clean implementation of dirty languages.
- Started coding with the nice high-level stuff.
- That gave us a very clean overall design.
- Edged in low-level ugliness later, where required.
- Even while the tool was already in production!
- Only possible since we kept it small and simple.
- Otherwise, such stunts would break the design.
Shun complexity!
This is a third reason why simplicity is key:
1. correctness and 2. security are well known.
But flexibility is important as well!
Ingo Schwarze: Mandoc in OpenBSD - page 25: CONCLUSIONS III -
BSDCan 2011, May 13, Ottawa
Move fast!
How a replacement project can succeed.
- Quickly put your work to real-world use.
- Do not let it rot in a corner of the OS.
- Keep moving fast, do not fear change.
- But don't trap your users with incompatible changes.
And keep the balance:
- No need to do it when it makes no difference.
- You won't find users when you break behaviour.
- You won't find bugs when you don't have users.
Ingo Schwarze: Mandoc in OpenBSD - page 26: FUTURE I - Mar and Apr 2011 -
BSDCan 2011, May 13, Ottawa
The future is already past.
When i proposed this talk, groff-1.20 was a plan.
We now provide a groff-1.21 port.
- Advantage of the move to ports even for groff lovers:
- It is much easier to update ports than base.
- And the GPL v3 doesn't hurt so much in the ports tree.
- NetBSD and FreeBSD are stuck with groff-1.19.2 which was released in 2005.
According to the ChangeLog, groff-1.21 has:
- Unicode, wide characters, Japanese localization.
- XHTML output (crappy, of course, but at least something).
- Many tbl(1) improvements, including MathML output.
- Better performance, bugfixes, features, and much more...
Related timeline:
2011 Mar 19: update ports groff from 1.15 to 1.21
2011 Mar 20: rudimentary eqn support by kristaps@
2011 Apr 24: tweak mandoc to conform to newest groff habits
2011 Apr 26: fixed groff-1.21 invocation for Imake ports
Ingo Schwarze: Mandoc in OpenBSD - page 27: FUTURE II -
BSDCan 2011, May 13, Ottawa
Not done...
Possible future directions.
- Infrastructure:
- Install manual sources, not preformatted manuals.
- Rewrite apropos(1) and makewhatis(8) to use mandoc.
- Use that to replace man.cgi on the websites.
- Functionality:
- Write pod2mdoc(1) in Perl.
- Implement -mdoc -Tman:
- millert@ wants to convert sudo(1) manuals to mdoc(7)
- but some systems neither want mdoc(7) nor mandoc(1)
- Implement -man -Tmdoc:
- to help with migration to modern tools.
- much more difficult to implement this direction.
- And of course:
- bugfixing, missing functionality, documentation, ...
Related timeline:
2011 Jul 02: p2k11 - worldwide main hackathon in Edmonton
2011 Sep 16: s2k11 - European general hackathon in Ljubljana
Ingo Schwarze: Mandoc in OpenBSD - page 28 -
BSDCan 2011, May 13, Ottawa
Thanks!
- Kristaps@ Dzonsons (bsd.lv)
- Joerg@ Sonnenberger (NetBSD)
- for important code contributions.
- for hosting an excellent mandoc hackathon at BEC.de.
- for lots of testing in the NetBSD tree.
- Jason McIntyre (jmc@)
- for excellently and tirelessly maintaining our manuals.
- for helping with countless bug reports.
- for discussing countless questions regarding mdoc(7).
- Theo de Raadt (deraadt@)
- for inviting Kristaps and getting mandoc imported.
(Otherwise, i might have missed the project.)
- for ongoing encouragement, in particular
to make OpenBSD developers and users our guinea pigs.
(None complained, they seemed to enjoy it.)
- Marc Espie (espie@)
- for getting ports integration done.
- for quite some help in various respects.
- Ulrich Spoerlein (uqs@ FreeBSD)
- for lots of bug reports.
- for a couple of patches and discussions.
- for lots of testing in the FreeBSD tree.
- Matthieu@ Herrb, Todd@ Fries, Miod@ Vallat
- for help with Xenocara integration.
- Peter Hessler (phessler@)
- for help with the regression infrastructure.
- for portability testing.
- Igor Sobrado (sobrado@)
- for lots of bug reports and discussions.
- Christian Weisgerber (naddy@)
- for very thorough testing.
For important bug reports and discussions:
- Stuart Henderson (sthen@)
- Landry Breuil (landry@)
- Todd Miller (millert@)
- Brad@ Smith (comstyle.com)
- Will Backman
- Thomas Klausner (wiz@ NetBSD)
- Sascha Wildner (DragonFly BSD)
- Werner Lemberg (GNU)
David Coppa - Edd Barrett - Giovanni Bechis - Gleydson Soares -
Ian Darwin - Janne Johansson - Jasper Lievisse Adriaanse - Kurt Miller -
Matthew Dempsky - Matthias Kilian - Nicholas Marriott - Paul Irofti -
Philipp Guenther - Remi Pointel - Ted Unangst - Thordur Bjornsson
(all OpenBSD)
Anthony J. Bentley - Chris Bennett - Frantisek Holop - Igor Zinovik -
James Jerkins - Maxim Belooussov - Mikolaj Kucharski - Nicolas Joly -
Pascal Stumpf - Ryan Flannery - Tim van der Molen - Tristan Le Guern -
Yuri Pankov
... and probably some i have forgotten (sorry for that)
For images under CC licenses:
http://www.flickr.com/photos/tomkoadam/4778126822/
http://www.flickr.com/photos/kristavandervoorden/4737488285/
http://www.flickr.com/photos/tiny_packages/5045038219/
http://www.flickr.com/photos/tambako/3578468294/
http://www.flickr.com/photos/gazzat/3495392530/
http://www.flickr.com/photos/garycycles7/5658207855/
http://www.flickr.com/photos/jimmy-jay/4672901414/
http://www.flickr.com/photos/66176388@N00/3436935367/
A Youngster on the Quantocks. -
Photo: Mark Robinson <me'nthedogs'@flickr> (CC)


{% extends "home/base.html" %} {% load static %} {% load humanize %} {% block content %}
GPCRdb contains reference data, interactive visualisation and experiment design tools for G protein-coupled receptors (GPCRs). GPCRdb curates sequence alignments, structures and receptor mutations from literature. Interactive diagrams visualise receptor residues (e.g. snakeplot and helix box plot) and relationships (e.g phylogenetic trees). See the GPCRdb graphical overview, video, articles or documentation.
GproteinDb and ArrestinDb will be published as separate web resources.
GPCRdb is developed by the David Gloriam group, integrates data from the large GPCR community and maintains an active collaboration with the Guide To Pharmacology (IUPHAR), GPCRmd and ERNEST. If you use the GPCRdb, please remember to cite us.
Photo: MRC Laboratory of Molecular Biology in Cambridge
#} {#The GPCRdb is developed by the Gloriam group.#} {# It integrates data from the large GPCR community and maintains an active collaboration with the#} {# Guide To Pharmacology (IUPHAR), GPCRmd and the European Research Network on Signal#} {# Transduction (ERNEST).#} {# If you use the GPCRdb, please remember to cite us.#} {#
#} {# #} {#


| unite {tidyr} | R Documentation |
Convenience function to paste together multiple columns into one.
unite(data, col, ..., sep = "_", remove = TRUE)
data |
A data frame. |
col |
The name of the new column, as a string or symbol. This argument is passed by expression and supports
quasiquotation (you can unquote strings
and symbols). The name is captured from the expression with
|
... |
A selection of columns. If empty, all variables are
selected. You can supply bare variable names, select all
variables between x and z with |
sep |
Separator to use between values. |
remove |
If |
Arguments for selecting columns are passed to
tidyselect::vars_select()
and are treated specially. Unlike other
verbs, selecting functions make a strict distinction between data
expressions and context expressions.
A data expression is either a bare name like x
or an expression
like x:y
or c(x, y)
. In a data expression, you can only refer
to columns from the data frame.
Everything else is a context expression in which you can only
refer to objects that you have defined with <-
.
For instance, col1:col3
is a data expression that refers to data
columns, while seq(start, end)
is a context expression that
refers to objects from the contexts.
If you really need to refer to contextual objects from a data
expression, you can unquote them with the tidy eval operator
!!
. This operator evaluates its argument in the context and
inlines the result in the surrounding function call. For instance,
c(x, !! x)
selects the x
column within the data frame and the
column referred to by the object x
defined in the context (which
can contain either a column name as string or a column position).
separate()
, the complement.
library(dplyr) unite_(mtcars, "vs_am", c("vs","am")) # Separate is the complement of unite mtcars %>% unite("vs_am", vs, am) %>% separate(vs_am, c("vs", "am"))


Even mercenaries should have more dignity than that! Those jewels must be cursed!