Describe Invisible Writing here.
Something that looks innocuous and featureless actually has some writing on it. You aren't able to see it with the naked eye; you'll need some way to reveal it.
A simple example is writing a messsage with citrus juice. Once it dries, the print becomes invisible. One must warm the paper to reveal the words. Other times, you will need specialized equipment such as a fluoroscope or a chromatic filter to view the writing. In fantasy worlds, magic or Green Rocks are needed to make the writing visible. Possibly, the writing can only be read by a specific person, or at a specific time frame or location. Otherwise, the writing is invisible.
As with any secret message, this is done so the message can't be read by just anyone, and can easily be overlooked during a search.
May lead to Fridge Logic: If one uses an "invisible ink" to write, wouldn't the writer have a hard time writing it? (It may be handwaved by turning the text invisible after it was written, in some way.)
Truth in Television: This was a valid secret communication technique right until the 20th century, when UV lamps (a/k/a "Wood's Light", "black light") rendered it obsolete.
Condensation Clue and Writing Indentation Clue are subtropes. See also See the Invisible on ways to make things visible. For examples where invisible ink gives something else invisibility, see Invisibility Ink.
Examples:
- A few breakfast cereals during The '70s would print trite messages on the boxes, disguised as random dopplings of color. A piece of tinted cellulose, usually red, was used to screen out the "noise" colors, leaving the remainder to form legible print.
- In Akagami no Shirayukihime Shirayuki and Ryuu are searching for an old book that describes a rare quickly spreading illness that has started appearing in Lyrias. When they finally track it down most of the writing has faded to the point of being illegible so they work with a botanist and another researcher to come up with a way to get the writing to show again.
- In Gugure Kokkuri San, Kokkuri-san is transformed into a woman by a cursed box whose sole contents is a piece of paper reading "I told you not to open it," and immediately burns the paper. Kohina reveals a little later that words would appear on the paper if it's held up to the light (probably some form of watermark).
- A major subplot in Lone Wolf and Cub details how the Yagyu clan has been using invisible writing as part of a plot to usurp control over the Shogunate. Itto discovering how to reveal the invisible writing and thereby threatening to reveal the Yagyu's grip on the Shogunate is treated by Retsudo as a far bigger problem than the fact that Itto is a One-Man Army out to slaughter the Yagyu clan down to the last.
- In Naruto, the Uchiha tablet on first glance gives the basic informations regarding secrets of the Uchihas. But use your Mangekyou Sharingan or Rinnegan and you will see even more details regarding the history of the ninja world. Such as the history of Senju and Uchiha war and the origin of the Ten-tails.
- In Ouran High School Host Club Tamaki's father sends him messages in invisible ink (made with lemon juice). The club believes that the messages come from the person sending them threatening letters and hilarity ensues.
- Sgt. Frog has a chapter where he receives a message from his superiors that had to be revealed by rubbing an eraser on it. In the anime, the message also gets partially revealed due to entry through the atmosphere.
- In Speed Racer Pops has put the blueprints to the Mach 5 in invisible ink on the windshield of the car.
- Wonder Woman (1942): Zara uses invisible ink to write on her victims without their knowledge which is then activated later in dramatic fashion to better convince them that her cult is legitimate.
- Gone in 60 Seconds (2000): Memphis (Nicolas Cage) and his crew use this to hide a list of target cars, from Detective Castlebeck. The writing is only visible under "black light".
- Who Framed Roger Rabbit: Mr. Acme was the inventor of the 'disappearing-reappearing ink' which would become invisible almost immediately, but become visible again through time. Mr. Acme also wrote his will with it, leading it to be believed lost.
- National Treasure: A secret message was written on the Declaration of Independence with invisible ink that was revealed with heat. Further clues were embedded in the Declaration of Independence, visible only through a pair of glasses with switchable chromatic filters.
- In Now You See Me, the Horsemen's New Orleans show seems to use some form of Invisible Ink which shows up under a flashlight.
- Constantine: Angela and her sister Isabela left hidden messages on windows and mirrors when they were kids, visible only when fogged by their breath. Isabela left her sister one last message before she was Driven to Suicide.
- One Charlie Chan mystery Charlie Chan in Shanghai has some writing on a piece of linen. The glyphs appear to be Chinese, but Chan declares them as gibberish. He then points out that, despite plenty of writing paper available, the marks were made on cloth. Chan rinses the linen in a bowl of water, which washes away some of the ink, but leaves the true message in broken Roman letters intact.
- In Pacific Rim, Newton tracks down Chau's kaiju-parts dealer by spotting hidden symbols on signposts with a UV penlight.
- Knives Out: Harlen writes messages to his adult daughter Linda in invisible ink, simply because it amuses both of them.
- Two short stories by Agatha Christie (one featuring Hercule Poirot and one Miss Marple), involve rich eccentrics writing their will in Invisible Ink, and challenging the heirs to find it.
- Encyclopedia Brown had a story which used lemon juice as the ink of choice.
- In Edgar Allan Poe's "The Gold Bug", the whole plot is triggered by a piece of parchment being accidentally held near a fire long enough to bring out a message in invisible ink.
- In Tolkien's Legendarium, there are several kinds of magical invisible writing. First is called "moon letters" and is written with silver pens and unknown ink that is only visible in moonlight. In The Hobbit, Thorin's map to Erebor has such invisible script. Second (not quite an ink but similar) is ithildin, a metal alloy that only reflects starlight and moonlight when certain magical spells are recited, and is normally transparent, used to decorate the Gates of Moria which blend seamlessly with rock. Revealing ithildin is the only way to see these gates.
- Bilbo Baggins's magic ring seemed ordinary enough, with nothing apparent on its inner surface. However, once Gandalf the Grey threw that ring into the hearth fire and later retrieved it, it's fateful inscription appeared: "One Ring to rule them all ..."
- Harry Potter:
- In Harry Potter and the Chamber of Secrets, the team initially thinks that Tom Riddle's diary was written with invisible ink, with Hermione trying spells and a magicked eraser called a "revealer" to try and make something visible. Subverted: The diary contains Tom Riddle's memories in a very literal sense, and is capable of responding to written messages.
- In Harry Potter and the Prisoner of Azkaban, Fred and George introduced the Marauder's Map, which doesn't just show the map of whichever building the holder is in, but also shows the footsteps of people. It looks like just an empty sheet of old paper... unless you know the chant for activating it.
- James Bond in On Her Majesty's Secret Service uses his urine ("the oldest [secret ink] in the world") to write down the names of the allergy treatment patients in Piz Gloria, before he tries to make his escape from the place.
- Briefly appears in one of the Deltora Quest books, Isle of the Dead. Tom the shopkeeper sends Lief, Barda and Jasmine a gift of firebeads and sweets. Since Tom is notorious for his No Hero Discount attitude they are wondering why he did so, when they notice that the wrapping they had left by the fire they just made now has writing on it. The wrapping is a note from Tom advising them on the next stage of their quest... with a postscript asking them, when convenient, to pay for the items he has sent.
- In In the King's Service, Alyce de Corwyn gets a letter from her late father that appears to have a banal message about a bequest of family jewels, yet he left a second message revealing that Vera Howard is really Alyce's twin sister that only becomes visible when Alyce activates her father's spell by kissing the wax seal.
- Mortally wounded curator Jacques Sauniere leaves an important clue scrawled on the Louvre's parquet floor, that can only be seen under ultraviolet light, in The Da Vinci Code. "O Draconian Devil / Oh Lame Saint." It was made not to implicate his killer, but rather to indicate his killer's objective.
- One of the Literature/Greyfriars stories had a main character receive a letter from a missing relative, asking whether he remembered a particular party trick. He doesn't, but the letter is left out in the hot sun for a while, which reveals the real message saying that the relative has been kidnapped.
- In Aunt Dimity and the Lost Prince, young neighbour Bree Pym shows Lori's young twins how to write invisibly with lemon juice and reveal the messages with the heat of a lightbulb. It's part of her unexpected arsenal of talents for entertaining kids, a bag of tricks that includes juggling, acrobatics, yoga and sleight-of-hand magic.
- The Count of Monte Cristo: The key to the colossal fortune was found in an old piece of paper used as a bookmark. When Faria tried to use it to light a candle, he noticed words forming on it and quickly extinguished it, but was arrested before he could find it.
- Discworld:
- Parodied in Witches Abroad. The witches come upon a dwarf mine, identified by invisible runes. Magrat states she can't see them, which Nanny Ogg points out is how you know you got your money's worth with invisible runes.
- The Unseen University faculty includes the Reader in Invisible Writings.
- The bracelet given to apprentice white witch Susan, in Alan Garner's fantasy novel The Moon of Gomrath, is apparently of plain silver with nondescript black inlay. But in times of great need, it manifests readable writing, which when spoken by her becomes a spell of great potency and confounds the creations of evil.
- Nick Velvet: In "The Theft of the Used Teabag", Nick's client is certain the teabags are being used to pass something along. After cutting the bag open, searching it for contraband and finding nothing, Nick points out the pasteboard tag on the bag could be used to pass on a message. There is the name of a meeting place written in invisible ink that is revealed by dunking the tag in hot tea.
- The Thinking Machine: In "The Broken Bracelet", Van Dusen is asked to uncover the secret of a blank scrap of paper found inside the eponymous bracelet. The secret is a cryptic set of directions written in invisible ink. When Hatch questions the feasibility of doing this in prison, Van Dusen points out lemon juice or milk would serve the purpose. (Presumably delicacy prevented him from mentioning the possibility of urine.)
- 3-2-1 Contact's "Bloodhound Gang" has a story called "The Case of the Secret Message" in which they find an old lady's stolen purse and finds that it only has a seemingly blank piece of paper. The Gang suspects invisible ink, but have to go through various methods to find out like heating it to expose lemon juice writing, which doesn't work. Eventually, the way to expose the writing is it to rub pencil graphite on the paper to expose the secret writing that was written in salt water.
- Arrow:
- One episode has the names of Starling City's most corrupt criminals written in a handbook owned by Oliver's father. He only realized it wasn't blank when he was about to burn it as kindling while marooned on the island and the names appeared from the heat. The ink can also be revealed by way of a special pair of glasses.
- The team finds some notes written the same way in Sara's boot in "The Magician" episode. Nyssa calls it "Ghost Ink" and says it is one of the standard methods that the League of Assassins employ for concealing secrets.
- Blindspot: Jane Doe's body is already covered in tattoos that contain hidden meanings but in the "Bone May Rot" episode, it is discovered that she also has tattoos that are only appear under the exact frequency of UV light that used for decontamination at the CDC.
- In the Bones Season 7 finale a man in a mental institution leaves a secret message written on the walls in his own saliva. It works like invisible ink; it only shows up under special light.
- On the Back Door Pilot for The Finder on Bones, the treasure map has writing that can only be revealed with blood.
- Doctor Who: In "Rosa", the Doctor has a marker with special ink that can be sonicked to make it invisible or visible as required, making it perfect for brainstorming on the walls of a motel without technically vandalizing the place.
- Elementary: When Sherlock and Joan retrieve the Body of the Week of the "Art in the Blood" episode for an autopsy, they are more than a little surprised to find that his apparently ordinary arms had been stolen and nothing else. After some investigation they find out that his ex-wife is a tattoo artist and he had her cover his arms with tattoos that only show up under UV light.
- An episode of Hetty Feather has a new Foundling (Eliza) arrive at the hospital and it turns out she stayed with the same foster family as Hetty. Hetty learns from Eliza that her foster brother mentioned the secret squirrel house they used to play at and that her foster brother did not mention Hetty to Eliza at all, leading Hetty to think that he has forgotten about her. When Hetty's friends learn of this, they have Eliza write a letter home, with the line "I hope you are reading this by your lovely warm fire" and on Eliza's letter, they write a message using lemon juice, which won't show up on the paper unless it is held up to a fire, to tell the foster brother what has happened to Hetty.
- In House of Anubis, Sibuna find an old dictionary but when they open it, nothing is written in it. Later it turns out the text was in invisible ink, and the heat from the flashlight made the words appear.
- In one episode of The Office (US), Dwight attempts to pass a secret message to the other salespeople by handing them letters with a second message written beneath the main text in invisible ink, hinting to them to expose the letters to heat to make the secret message visible. Of course, none of them bothers to do so. Dwight also cheerfully admits that the "invisible ink" in question is in fact his own urine.
- Person of Interest. Finch goes to investigate a lockup rented by a terrorist group. It appears to be empty, but when an infra-red light is shined on the wall, a message has been written there.
- In Raumschiff GameStar, the employee contract clause that forces all crew members (except The Captain and the medical officer) to wear bright orange overalls is printed in ink that is only visible if you hold the paper against the light of a full moon on a certain date and day of the week.
- One of the things Abraham Woodhull does as part of his spy work for George Washington in Turn is transmit messages via invisible ink that requires the application of a coat of "reagent" for the message to be visible.
- Dungeons & Dragons
- The Book of Marvelous Magic has Inkwell of Concealment, which is an Everfull Inkwell, but after a hour everything written with its ink vanishes and can be read only via effects allowing to see invisible objects.
- Tolkien's version above was thrown in when sourcebook Player's Options: Spells & Magic introduced 'Moon Rune' spell that displays letters when its triggering condition is met, including moonlight in the proper phase or presence of creatures (set by species).
- The spell Arcane Mark can functionally be an invisible ink. The campaign setting Eberron notices this, and uses it on documents to increase the difficulty of forging.
- Forgotten Realms lore has Thayan "cobrascale ink", normally invisible and bright when heated.
- At Universal Studios' The Wizarding World of Harry Potter, the Scribbulus store has a scroll with invisible ink on it, which can only be revealed via a spell.
- Alone in the Dark 3: At one point, while exploring the town hall, you find an apparently blank book. Another tips you of its true nature and what to do with it: reading in while standing near a light candle will reveal it's actually a book written by Pregtz, the Big Bad from the first game.
- In the Assassin's Creed series, many instances exist of characters using Eagle Vision in order to see hidden messages.
- The dilapidated studio of Bendy and the Ink Machine has messages all over its walls. Some of them can't be seen until Henry gets a special tool from Allison.
- In Dark Fall The Journal, the picture of a pigeon can be heated over the gas stove upstairs, causing the names of four Lyrics to appear.
- In the Nancy Drew game The Haunted Carousal; she helps out the bookkeeper with some puzzles that would reconnect her childhood (long story). One puzzle involved a piece of lemon scented paper that showed a message when ironed.
- In the video game The Riddle Of The Sphinx, holding a sheet of paper over the candle in the tent lets you see a secret message in it.
- Uncharted 2: Among Thieves has several maps, inscriptions, etc. showing the way to the legendary Cintamani Stone that are only visible in the blue light created by burning a special resin. The resin is the congealed sap of a tree that grants great physical prowess and immortality, the true form of the Stone.
- My Little Pony: Friendship Is Magic. As a practical joke, Pinkie Pie and Rainbow Dash replaces Twilight Sparkle's ink with invisible ink. Twilight eventually did the same thing to Princess Celestia.
- In Avatar: The Last Airbender episode "The Avatar and The Fire Lord", Zuko received a note with a secret message written in invisible ink which was revealed with heat.
- In the second season of Gravity Falls, Dipper discovers that the Journals have additional writing in invisible ink made visible through a black light.
- In an early episode of Rocky and Bullwinkle, Natasha reveals a message that was in invisible ink by holding the paper in front of a candle: "Keel Moose." Boris drops a safe to land on Bullwinkle's head. After the Commercial Break Cliffhanger Natasha says that two more words have appeared: "Do Not." Boris races the safe to save Bullwinkle.
- This was also used in the Garfield and Friends episode "The Legend of Long Jon". Garfield and Odie were reading from the journal of Jon's pirate ancestor Long Jon Arbuckle, when Odie started drooling on an apparently blank page, which causes writing to appear on the page. It turned out that Long Jon Arbuckle had written on the blank pages in invisible ink, telling about how he was able arrest some bandits that were carrying phony documents.
- Cale Tucker, The Hero of Don Bluth's Titan A.E., receives a ring from Captain Korso. The ring has been coded to Cale's genetics so that it reveals a star map on Cale's hand. As a further safeguard, the map's pointer shifts direction while Cale is standing on a platform on Sessarim.
- Similar to the Gone in 60 Seconds (2000) example above, an episode of Fillmore! involving a bike thief ring that used the same 'special chalk' trick, albeit replacing blacklight exposure with special lenses. This ends up helping to catch the secret leader of thief ring, who had gotten some of said chalk on their shirt.
- One poor unfortunate decided to rob a bank and his "disguise" was lemon juice on his face, thinking that, per its use as invisible ink, it would keep the security cameras from recording him. He was wrong.
- The idea of using citrus oils as in National Treasure was a common means of sending covert messages through the end of the Cold War. An ordinary incandescent light bulb is usually enough to reveal such messages.
- A really Squicky example: Fresh semen may be used as an invisible ink much as lemon juice may be applied. Apparently, all men can access a stock even if in a place where no lemons are available.
- Saliva does the job, too, so you don't have to be male to improvise Invisible Writing.


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Robson Jaques1,2, Haroldo Atanasio de Souza Pereira Leite1 , Moacir Lacerda1,2, Julio Cesar Paro1,3 Clovis Lasta Fritzen1,2 Abstract It is presented a methodology for analysis of extreme events in the Paraguay River Basin. The number of electric discharges and stratiform and convective precipitation data are crossed in the search for correlations between them. Extreme events can be found from the establishment of average precipitation and the number of discharges recorded in the same area. Spatial patterns of distribution for electric discharges are detected and some causes for these patterns are discussed. There is a high correlation between precipitation and the number of lightning. The results indicate also that orography and the flooded area may be important factors in defining patterns of precipitation and electric discharges. Ler trabalho completo
Luiz Dirceu Thomaz Junior1 , Moacir Lacerda1 , Robson Jaques1 , Julio Cesar Paro2,1, Clovis Lasta Fritzen1 , Abstract In this paper we present results of comparison of lightning channel tortuosity calculated by simulation and calculated using photographic records presented in the literature. We simulated the last 1500 m of channel in several distances of cloud and under several regimen of conductivity considered as a tensor. The tortuosity of simulated channel depends on the conductivity. We choose the simulated cases where the mean tortuosity angles are close to 17o and 9 o . These angles correspond to the values presented in literature for mean tortuosity of natural and triggered lightning respectively. In these selected cases we compare the distribution of tortuosity according to height with that one calculated for natural and triggered lightning in Florida (Idone and Orvile, 1988). Some discussion about this comparison is presented. Ler trabalho completo
Moacir Lacerda, Robson Jaques The Lightning activity is analyzed in a scale of hour, by using the lightning detection system STARNET data to build a diurnal lightning activity curve. We rebuilt Carnegies curve by using hour averaged data of lightning incidence inside windows over South America, Africa and Oceania. The shape of the curve is similar to those of literature with small differences of time of peak for lightning activity. The peaks of lightning activity occurred at 08:30 over Oceania, 14:00 over Africa and 18:30 over South America. Ler trabalho completo
Moacir Lacerda, Robson Jaques, Marcelo Magalhães Fares Saba, Diovane Rodolfo Campos, Kleber Pinheiro Nacaratto Abstract In this paper we obtained the Carnegie's curve for South America by using data from a global lightning detection system in a scale of seconds. Carnegie's curve is a measurement of electrical activity of the planet. It can be obtained by direct averaging the measurements of electric field (in a scale of hours)[1], or can be obtained (in the same scale of time) from lightning activity [2], [3], [4]. The lightning data used to monitor lightning activity in this study was recorded by the sensors of the BrasilDAT lightning location system. The dataset consists of cloud and cloud-to-ground discharges detected within a 100km-radius circle centered on latitude -23.4587 and longitude -46.7667, corresponding to an area in and around the city of São Paulo, SP, Brazil . The methodology consists of calculating the Carnegie's curve in a scale of hours, plotting the lightning activity data collected of BrasilDAT and compare it with the curve obtained by Lacerda and Jaques [4] by using STARNET data. Ler trabalho completo
Carina Schumann, Marcelo M. F. Saba, Amanda Romão de Paiva , Robson Jaques,Marco A. S. Ferro,Tom A. Warner Abstract Studies of upward flashes from tall structures around the world have been reported since 1939. The characteristics of the triggering mechanism and of the upward flashes are of increasing interest to wind power turbines, telecommunication toware and power distribution companies. Observations of upward flashes in Brazil are recent. Since 2012, upward events were observed in all different seasons of year. They initiate on several towers in Sao Paulo, a city in southeast Brazil at an average elevation of around 800 meters above sea level and a flash density of 15 flashes/km.year. Some of the towers are located on top of buildings or hills. In this study, we will present some characteristics of these upward flashes, based on high speed video observation: flash duration, presence of subsequence of return stroke, previous lightning events, initial continuous current pulses and the presence recoil leader. Ler trabalho completo
Robson Jaques, Moacir Lacerda ABSTRACT: In this paper we present experimental results obtained by the use of the method Lightning Mapping Array with Electric Field measurements on ground (LMA-EF). This method allows to measure the positions and magnitudes of the electric charges (Q) inside the thunderstorm clouds. The data used to validate the experiment were provided by the Vale do Paraiba CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GPM (GlobAl Precipitation Measurement) ) project campaign, that took place in São Paulo - Brazil between December of 2011 and January of 2012. The LMA data can provide us the position (R) of the electric charges centers and a network of electric field mill provides data of electric field (E). Combining LMA data with the measurements of electric field on the ground is possible to determine the magnitude of the electric charges, by using the inversion of the coulomb law in matrix form: Q = (RT.R)-1.RT.E. An algorithm was written to make this estimation automatically. After the determination of the electric charge structure, the algorithm recalculates the direct Coulombs Law and checks the results by fitting data of electric field on ground. Ler trabalho completo
Moacir Lacerda,1,2, Robson Jaques2, Carlos Augusto Morales Rodriguez4, , Evandro Moimaz Anselmo4, Clóvis Lasta Fritzen1, Julio Cesar Paro3, Widinei Alves Fernandes3,2, Waldeir Moreschi Dias1 Abstract In this paper we present preliminary results of the study of thundercloud structure over urban area. The sensors were developed by LCA-UFMS team and are operated now by IAG-USP team. To solve Coulombs law by using the records of two electric field mill (EFM) (at rate of one second) we developed a computational code that calculates second by second the magnitude and localization of charges main centers. This methodology allows to find results with good precision. Analyzing the solutions of Coulombs law, surprisingly we noticed that there are inversion of the sign of charges from positive to negative or negative to positive in those regions where the centers were located in a scale of several seconds. We dont have definitive explanation about this but it is possible that fast discharges inside the cloud are responsible for this behavior. Ler trabalho completo
Robson Jaques1,2, Moacir Lacerda1,2, Haroldo Atansio de Souza Pereira Leite1, Widinei Alves Fernandes3. In this paper we present results of analysis of lightning data on Paraguay Basin. The corners of spatial window, for this analysis are: RightDown = (28 S, 51 W), LeftUp =(14 S, 68 W) and the period of time is January 2008 to February 2009. Lightning data were provided by starnet system through IAG-USP. Charts containing data are presented for each month and for this period of time. These charts contain information for calculate engineering parameters of protection. The main results are: the lightning activity is stronger over Andess Ridge and over the cerrado. The main flooded area (pantanal) showed low lightning activity. The time of highest activity was around 18:00 UTC. There is another small peak of activity around 12:00 UTC. This data confirm previous results of preliminary research developed by LCA-UFMS team using satelites data of LIS (Lightning Image Sensor) at TRMM (Tropical Rain Measurement Mission) project. So, the main vulnerable area to extreme events of lightning discharge are located around the pantanal. Ler trabalho completo
O. Pinto Jr.1, D. G. Guedes1, M. M. F. Saba1, I. R. C. A. Pinto1, and M. Lacerda2 Abstract. After 17 years of research at Morro do Cachimbo station (MC) in Brazil, 51 flashes with strokes higher than 2 kA were registered. The data are compared with similar data obtained from the Mount San Salvatore station (SS), Switzerland, in terms of the incidence of downward or upward flashes, polarity, and flash multiplicity. The comparison indicates that at MC the percentage of upward flashes and the multiplicity of negative downward flashes are higher than at SS, while the percentage of downward positive flashes is lower. Key words. Meteorology and atmospheric dynamics (atmospheric electricity; lightning; instruments and techniques) Ler trabalho completo
Moacir Lacerda We make an historical review about research on lightning and present data on currentes recorded when thunder strokes, analysing the thecniques used to ob- tain those data. We present the model by Lin et al., which relates elds and currents, treating the return stroke as an irradiating antenna and tearing the channel currents in three components, modelling them separately. One of them is the corona current, due to the dive of the charges kept around the channel heading to the cannel. Lin uses two parameters a and ,6 in the expression for the corona current, to his theoretical functions to the experimental data. Our work consistid in deriving a model of electrical circuits for the main channel and its neighborhoods described by a differential equation which homogeneous solution for the current has the same shape of Lins expressions to the corona current. a and B reveal themselves depen- dent upon the electrical parameters R(z), L(z) and C(z), representing the resistive, inductive and capacitive elements associated to the channel, trough the equations roots. That equation describes the dynamics associated to the development of currents in the main channel of the lightning, and allow us obtain an expression to the pulse current as a particular solution. At least, we estimate the parameter C(z) in 10E-6 F and calculate, to the channel, a resistance of approximately 10E+2 - 10E+3 ohms and an indutance of 10E-4 H. This publication is a tribute to MARIA CAROLINA NEMES who was my source of inspiration during my master degree at USP (São Paulo University) Ler trabalho completo
Modelagem da Corrente de Descarga e Cálculo dos Campos Eletromagnéticos Moacir Lacerda Monografia referente ao Exame Integrado (Qualificação) do Curso de Pós Graduação em Geofísica Espacial. Ler trabalho completo
Moacir Lacerda1,3, Carlos Augusto Morales Rodriguez2, Hilton Luiz Monteiro Junior3, Evandro Moimaz Anselmo2, João Ricardo Neves2, Robson Jaques1,3, Eduardo Fernando Gomes2, Clovis Lasta Fritzen3 ,Wagner Dal Piva Rocamora3, Kaian Lopez Fernandes3,Julio Cesar Paro4,3, Widinei Alves Fernandes1,3 1 Universidade Federal de Mato Grosso do Sul Centro de Ciências Exatas e Tecnologias, Pós Graduação em Tecnologias Ambientais -UFMS-CCET-PGTA 2 Universidade de São Paulo Instituto de Astronomia Geofísica e Ciências Atmosféricas USP-IAG 3 Universidade Federal de Mato Grosso do Sul Centro de Ciências Exatas Laboratório de Ciências Atmosféricas (LCA) 4Instituto Federal de Mato Grosso do Sul, IFMS Abstract. We calculate electrical structures axially distributed in space based on measurements of electric field mill network on ground by solving the inverse problem of Coulomb's law. It is not trivial to use such approach and a methodology for dealing with mathematical problems of detecting solutions is presented. As an example we fit data from a field mill network by using this technique. A preliminary results and discussion are presented to improve this methodology in a more general case. Ler trabalho completo
MONTEIRO, H. L. JR. The objective of this work is to simulate clouds that are quite similar to the natural clouds, and compare the profiles of electric field. We simulate the structure of electric charges inside the clouds for tripolar and quadripolar cases. The vertical profiles of electric field and along the ground (z = 0) close to cloud were obtained, too. Another objective is use the values of electric field at z = 0, that simulate the electric field on ground, to solve the inverse problem of Coulombs Law. These values are calculated for a known structure and will be used to study the conditions that makes possible to discover the structure of charges that generate such values of electric field. It appears that the software properly simulates the clouds from the charge density, independent of the magnitudes of the charges, and is able to reproduce the localization of the charge centers. Under the center of the cloud, the vertical profiles are almost linear therefore the solutions obtained are very poor. The ideal region to obtain the vertical profiles that detect the charge structure of the cloud is close to the edges of the cloud. Ler trabalho completo
Moacir Lacerda, Luana Feitosa, Oniel Rodrigues Silvestre , Andressa Duarte, Clovis Lasta Fritzen, Waldeir Moreschi Dias , Robson Jaques Verly Abstract - In this paper we present details of construction and calibration of an Electric Field Mill (EFM) and first results of data analysis collected between 2013 and 2015 of an EFM network installed in the city of Campo Grande, Mato Grosso do Sul, Brazil and operated by the Laboratory of Atmospheric Sciences of the Physics Institute from the Federal University of Mato Grosso do Sul (www.lca.ufms.br). We present data analysis of 21 storms and fair weather measurements. We detected some patterns of previous discharges inside clouds that allow giving some insights of how to obtain an alert of lightning risk. The end of storm (EOS) was analyzed too. The fair weather electric field was analyzed by using Fourier Transform and allowed to detect the frequency of several harmonics. We used the first 21 harmonics to fit the data curve. The main oscillation has a period of about 12 hours. The system was monitored by cameras and we could synchronize the electric field measurement with video image. Some images of lightning discharge are showed. Some details of the sensors calibrating are presented. Ler trabalho completo


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--- layout: post title: Why I Still Have No Posts in Google+ date: '2011-09-07 08:03:10 -0700' mt_id: 1463 blog_id: 1 post_id: 1463 basename: why-i-still-have-no-posts-in-google-plus categories: - high-geekery - google ---
I belong to a lot of social networks. Pretty much any time I hear about a new one, I sign up for the "bbrown" username. I have learned my lesson about waiting to register for these things: having a common first name and surname, the late bird gets the "bbrown217" or other such contortions. (I almost had bbrown.com, after Burr-Brown was acquired by Texas Instruments in 2000. I checked every day waiting for the expiration hold to come off. Every. Single. Day. Except on my birthday, that is, because I was busy. Guess when the hold came off. I still bristle at that loss.)
But I have to say that I don't have much passion for any of them. I like Twitter a lot—mostly because there's a high signal to noise ratio on the people I follow and the 140-character short form makes it drop-dead easy to write something. But mostly I don't care for them because your content is locked away, subject to the whim of the provider to allow you to export it out of its cage.
I may be biased, but owning your own domain and hosting your own content is the best and safest form of expression. As long as you pay your bills, no one can really silence you and you—mostly—get to decide what the public can see. On the social networks, other people can decide that your views are "hateful" or "spam" or "worthless tripe" and get it taken down.
Over here, though, I get to say whatever I want however I want. This is my soap box.
In my time on the Internet, I've seen many sites come and fade into obscurity. I've seen social networks actively worked and then slide into disuse—fallen prey to passing whims both personal and corporate. This Web site's been active for the better part of 9 years now and there's no reason to suspect that it won't be around for another decade or two.


It's easy to get ready to develop on the MangOH board with a WP85 module:
Assemble
Install Software
Complete information about MangOH is available from mangoh.io and the Sierra Wireless Source mangOH page.
Copyright (C) Sierra Wireless Inc. Use of this work is subject to license.


the auth options
Set the charset used for encoding / decoding text data from/to SockJS
a reference to this, so the API can be used fluently
The path of the inputrc config.
a reference to this, so the API can be used fluently
Set {@code shell.html} resource to use.
a reference to this, so the API can be used fluently
The SockJS handler options.
a reference to this, so the API can be used fluently
Configure the SockJS path, the default value is {@code /term/*}.
a reference to this, so the API can be used fluently
Set {@code term.js} resource to use.
a reference to this, so the API can be used fluently
Set {@code vertxshell.js} resource to use.
a reference to this, so the API can be used fluently
Set the charset used for encoding / decoding text data from/to SockJS
the charset to use
a reference to this, so the API can be used fluently
The path of the inputrc config.
the path of the inputrc config
a reference to this, so the API can be used fluently
Set {@code shell.html} resource to use.
the resource
a reference to this, so the API can be used fluently
The SockJS handler options.
the options to use
a reference to this, so the API can be used fluently
Configure the SockJS path, the default value is {@code /term/*}.
the new SockJS path
a reference to this, so the API can be used fluently
Set {@code term.js} resource to use.
the resource
a reference to this, so the API can be used fluently
Set {@code vertxshell.js} resource to use.
the resource
a reference to this, so the API can be used fluently
Generated using TypeDoc
The web term configuration options.
Julien Viet


<
Events
X
Add event form:
Select polluting event:
-- select an option --
Car Journey
Plane Journey
Processed Meat Consumption
Washer/Dryer usage
Clothing purchase
Start date:
Duration (Days):
Please Check all fields are filled out correctly and try again
Add Event
+
-
S
M
T
W
T
F
S


Here we setup each page transition to each mousewheel "step" generated by the plugin.
It handles many mousewheel types (click wheels, trackpads, magic trackpads/mices, etc.), and handles both vertical and horizontal scrolls.
Try scrolling in here...
Yes, you can setup multiple scroll zones.
Copyright © 2014. Arnaud Mondit. MIT License.


Here is an example of how such a decorator (e.g. /decorators/main.vm) might look like:
#parse ("/includes/decorators/header.vm")
$title
 $head
 $title
 $body 	 #parse ("/includes/decorators/footer.vm")
[web-app]/WEB-INF/lib
.
The SiteMesh distribution comes with velocity-dep-1.3.1.jar.[web-app]/WEB-INF/lib
.
The SiteMesh distribution comes with velocity-tools-view-1.1.jar.[web-app]/WEB-INF/lib
.
The SiteMesh distribution comes with commons-collections.jar.[web-app]/WEB-INF/web.xml
within the <web-app>
tag:<servlet> <servlet-name>sitemesh-velocity</servlet-name> <servlet-class>com.opensymphony.module.sitemesh.velocity.VelocityDecoratorServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>sitemesh-velocity</servlet-name> <url-pattern>*.vm</url-pattern> </servlet-mapping>
decorators.xml
to reference a .vm
decorator.A working example is included with the SiteMesh distribution, under the src/example-webapp directory.
| $request (from VelocityViewServlet) | The HttpServletRequest object |
| $response (from VelocityViewServlet) | The HttpServletResponse object |
| $session (from VelocityViewServlet) | The HttpSession object |
| $application (from VelocityViewServlet) | The ServletContext object |
| $base | request.getContextPath() |
| $title | Parsed page title (<title>...<title>) |
| $head | Parsed page head |
| $body | Parsed page body |
| $page | SiteMesh's internal Page object |
| Anything else | Search for the attribute by that name in the request, session and application scopes |


- 一、作業系統
- 二、Linux 程式設計
一、作業系統
- 課程簡報
- 參考資料
(一) Thread Pools
- Create a number of threads in a pool where they await work.
- Advantages:
- Usually slightly faster to service a request with an existing thread than create a new thread.
- Allows the number of threads in the application(s) to be bound to the size of the pool.
- Separating task to be performed from mechanics of creating task allows different strategies for running task.
- Tasks could be scheduled to run periodically.
(二) OpenMP
- Set of compiler directives and an API for C, C++, FORTRAN.
- Provides support for parallel programming in shared-memory environments.
- Identifies
parallel regions
– blocks of code that can run in parallel.
#pragma omp parallel
- Create as many threads as there are cores.
#pragma omp parallel for
for(i = 0; i < N; i++) {
c[i] = a[i] + b[i];
}
// Run for loop in parallel
Example
#include <omp.h>
#include <stdio.h>
int main(int argc, char *argv[]) {
/* sequential code */
#pragma omp parallel
{
printf("I am a parallel region.");
}
/* sequential code */
return 0;
}
(三) Threading Issues
1. Semantics of fork() and exec()
- Does fork() duplicate only the calling thread or all threads?
- Some UNIXes have two versions of fork
- Exec() usually works as normal – replace the running process including all threads.
2. Signal Handling
- Signals are used in UNIX systems to notify a process that a particular event has occurred.
- A
signal handler
is used to process signals.- Signal is generated by particular event
- Signal is delivered to a process
- Signal is handled by one of two signal handlers:
- default
- user-defined
- Every signal has
default handler
that kernel runs when handling signal.- User-defined signal handler can override default.
- For single-threaded, signal delivered to process.
- Where should a signal be delivered for multi-threaded?
- Deliver the signal to the thread to which the signal applies.
- Deliver the signal to every thread in the process.
- Deliver the signal to certain threads in the process.
- Assign a specific thread to receive all signals for the process.
3. Thread Cancellation
- Terminating a thread before it has finished.
- Thread to be canceled is target thread.
- Two general approaches:
Asynchronous cancellation
terminates the target thread immediately.Deferred cancellation
allows the target thread to periodically check if it should be cancelled.
- Pthread code to create and cancel a thread:
pthread_t tid;
/* Create the thread */
pthread_create(&tid, 0, worker, NULL);
...
/* Cancel the thread */
pthread_cancel(tid);
4. Thread-Local Storage
Thread-local storage (TLS)
allows each thread to have its own copy of data.- Useful when you do not have control over the thread creation process (i.e., when using a thread).
- Different from local variables
- Local variables visible only during single function invocation.
- TLS visible across function invocations
- Similar to static data
- TLS is unique to each thread.
5. Scheduler Activations
- Both M:M and Two-level models require communication to maintain the appropriate number of kernel threads allocated to the application.
- Typically use an intermediate data structure between user and kernel threads –
lightweight process (LWP)
- Appears to be a virtual processor on which process can schedule user thread to run
- Each LWP attached to kernel thread.
- How many LWPs to create?
- Scheduler activations provide
upcalls
- a communication mechanism from the kernel to theupcall handler
in the thread library. - This communication allows an application to maintain the correct number kernel threads.
(四) Thread Scheduling
- Distinction between user-level and kernel-level threads.
- When threads supported, threads scheduled, not processes.
- Many-to-one and many-to-many models, thread library schedules user-level threads to run on LWP.
- Known as
process-contention scope (PCS)
since scheduling competition is within the process. - Typically done via priority set by programmer.
- Known as
- Kernel thread scheduled onto available CPU is
system-contention scope (SCS)
– competition among all threads in system.
(五) Pthread Scheduling
- API allows specifying either PCS or SCS during thread creation.
PTHREAD_SCOPE_PROCESS
schedules threads using PCS scheduling.PTHREAD_SCOPE_SYSTEM
schedules threads using SCS scheduling.
- Can be limited by OS – Linux and Mac OS X only allow
PTHREAD_SCOPE_SYSTEM
.
(六) Multiple-Processor Scheduling
- CPU scheduling more complex when multiple CPUs are available.
Homogeneous processors
within a multiprocessor.Asymmetric multiprocessing
– only one processor accesses the system data structures, alleviating the need for data sharing.Symmetric multiprocessing (SMP)
– each processor is self-scheduling, all processes in common ready queue, or each has its own private queue of ready processes.- Currently, most common
Processor affinity
– process has affinity for processor on which it is currently running.- soft affinity
- hard affinity
- Variations including
processor sets
- Load Balancing - attempts to keep workload evenly distributed.
Push migration
– periodic task checks load on each processor, and if found pushes task from overloaded CPU to other CPUs.Pull migration
– idle processors pulls waiting task from busy processor.
(七) Socket - Message Passing
1. What is a socket？
- An interface between application and network.
- The application creates a socket.
- The socket type dictates the style of communication.
reliable
vs.best effort
connection-oriented
vs.connectionless
- Once configured the application can
- pass data to the socket for network transmission
- receive data from the socket (transmitted through the network by some other host)
2. Two essential types of sockets
(1) SOCK_STREAM
- a.k.a. TCP
- reliable delivery
- in-order guaranteed
- connection-oriented
- bidirectional
(2) SOCK_DGRAM
- a.k.a. UDP
- unreliable delivery
- no order guarantees
- no notion of “connection” – app indicates dest. for each packet
- can send or receive
3. Connection setup
課程作業
-
自 Client 端輸入一整數，將數字傳至 Server 端判斷是否為質數，再將結果回傳自 Client。
-
client
部份
/* Make the necessary includes and set up the variables. */
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
int main()
{
int sockfd;
int len;
struct sockaddr_in address;
int in; // integer
int result;
// char ch = 'A';
/* Create a socket for the client. */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
/* Name the socket, as agreed with the server. */
address.sin_family = AF_INET;
address.sin_addr.s_addr = inet_addr("<IP_ADDRESS>");
address.sin_port = 9453;
len = sizeof(address);
/* Now connect our socket to the server's socket. */
result = connect(sockfd, (struct sockaddr *)&address, len);
if(result == -1) {
perror("oops: Client");
exit(1);
}
/* We can now read/write via sockfd. */
printf("Please key in an integer：");
scanf("%d", &in);
write(sockfd, &in, sizeof(int));
read(sockfd, &in, sizeof(int));
if (in == 1)
printf("Result from Server：數字'是質數'\n");
else
printf("result from server：數字'不是質數'\n");
close(sockfd);
exit(0);
}
server
部份
/* Make the necessary includes and set up the variables. */
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
int main()
{
int server_sockfd, client_sockfd;
int server_len, client_len;
struct sockaddr_in server_address;
struct sockaddr_in client_address;
/* Create an unnamed socket for the server. */
server_sockfd = socket(AF_INET, SOCK_STREAM, 0);
/* Name the socket. */
server_address.sin_family = AF_INET;
server_address.sin_addr.s_addr = inet_addr("<IP_ADDRESS>");
server_address.sin_port = 9453;
server_len = sizeof(server_address);
bind(server_sockfd, (struct sockaddr *)&server_address, server_len);
/* Create a connection queue and wait for clients. */
listen(server_sockfd, 5);
while(1) {
int i = 0, count = 0; // Set loop
char in;
printf("Server waiting...\n");
/* Accept a connection. */
client_len = sizeof(client_address);
client_sockfd = accept(server_sockfd,
(struct sockaddr *)&client_address, &client_len);
/* We can now read/write to client on client_sockfd. */
read(client_sockfd, &in, sizeof(int));
printf("Input from Client = %d\n",in);
for (i = in; i > 0; i--)
if (in % i == 0)
count++;
if (count > 2)
in = 0;
else if (count <= 2)
in = 1;
write(client_sockfd, &in, sizeof(int));
close(client_sockfd);
}
}
- 執行結果
二、Linux 程式設計
課堂練習 (一)
-
將 Socket 以 multithread 的方式執行：
-
Server
部份
/* Make the necessary includes and set up the variables. */
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <pthread.h>
void *thread_function(void *arg);
int main()
{
int server_sockfd, client_sockfd;
int server_len, client_len;
struct sockaddr_in server_address;
struct sockaddr_in client_address;
pthread_t a_thread;
void *thread_result;
int res;
/* Create an unnamed socket for the server. */
server_sockfd = socket(AF_INET, SOCK_STREAM, 0);
/* Name the socket. */
server_address.sin_family = AF_INET;
server_address.sin_addr.s_addr = inet_addr("<IP_ADDRESS>");
server_address.sin_port = 9734;
server_len = sizeof(server_address);
bind(server_sockfd, (struct sockaddr *)&server_address, server_len);
/* Create a connection queue and wait for clients. */
listen(server_sockfd, 5);
while(1) {
printf("\nServer waiting...\n");
/* Accept a connection. */
client_len = sizeof(client_address);
client_sockfd = accept(server_sockfd, (struct sockaddr *)&client_address, &client_len);
res = pthread_create(&a_thread, NULL, thread_function, (void *)(long)client_sockfd);
if (res != 0) {
perror("Thread creation failed");
exit(EXIT_FAILURE);
}
}
}
/* We can now read/write to client on client_sockfd. */
void *thread_function(void *arg) {
int i, j, tmp = 0, get_n;
int client_sockfd = (long)arg;
int *buf;
read(client_sockfd, &get_n, sizeof(get_n));
buf = (int *) malloc(get_n * sizeof(int));
read(client_sockfd, buf, get_n * sizeof(int));
printf("sort arr[%d] from client:\n", get_n);
for (i = 0; i < get_n; i++) {
for (j = 0; j < get_n; j++) {
if (buf[i] < buf[j]) {
tmp = buf[i];
buf[i] = buf[j];
buf[j] = tmp;
}
}
}
for (i = 0; i < get_n; i++)
printf("arr[%d] = %d\n", i, buf[i]);
// sleep(3);
write(client_sockfd, buf, get_n * sizeof(buf));
close(client_sockfd);
pthread_detach(pthread_self());
pthread_exit(0);
}
Client
部份
/* Make the necessary includes and set up the variables. */
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#define SIZE 5
int main()
{
int sockfd;
int len;
struct sockaddr_in address;
int result, n;
/* Create a socket for the client. */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
/* Name the socket, as agreed with the server. */
address.sin_family = AF_INET;
address.sin_addr.s_addr = inet_addr("<IP_ADDRESS>");
address.sin_port = 9734;
len = sizeof(address);
/* Now connect our socket to the server's socket. */
result = connect(sockfd, (struct sockaddr *)&address, len);
if (result == -1) {
perror("oops: client!");
exit(1);
}
/* We can now read/write via sockfd. */
int i, j, tmp = 0, s = SIZE;
int arr[SIZE] = {4, 7, 1, 8, 3};
int rec[SIZE] = {0, 0, 0, 0, 0};
printf("%d\n", s);
write(sockfd, &s, sizeof(int));
printf("\noriginal from client - arr[]\n");
for (i = 0; i < SIZE; i++)
printf("arr[%d] = %d\n", i, arr[i]);
write(sockfd, arr, sizeof(arr));
read(sockfd, rec, SIZE * sizeof(rec));
printf("\nresult from server - rec[]\n");
for (i = 0; i < SIZE; i++)
printf("rec[%d] = %d\n", i, rec[i]);
close(sockfd);
exit(0);
}
- 執行結果
課堂練習 (二)
- 矩陣相乘
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <pthread.h>
#include <time.h>
#define NUM_THREADS 5
#define MSIZE 10
static double getDoubleTime();
// void check();
void *thread_function(void *arg);
// srand(time(NULL));
// int a = (rand() % 10) + 1;
int A[MSIZE][MSIZE];
int B[MSIZE][MSIZE];
int C[MSIZE][MSIZE];
int D[MSIZE][MSIZE];
int main(void) {
int res;
int i, j;
srand(time(NULL));
for (i = 0; i < MSIZE; i++) {
for (j = 0; j < MSIZE; j++) {
A[i][j] = 1; // (rand() % 10) + 1;
B[i][j] = 2; // (rand() % 10) + 1;
}
}
pthread_t a_thread[NUM_THREADS];
void *thread_result;
int lots_of_threads;
double start_time = getDoubleTime();
for (lots_of_threads = 0; lots_of_threads < NUM_THREADS; lots_of_threads++) {
res = pthread_create(&(a_thread[lots_of_threads]), NULL, thread_function, (void *)(long)lots_of_threads);
if (res != 0) {
perror("Thread creation failed");
exit(EXIT_FAILURE);
}
// sleep(1);
}
printf("Waiting for threads to finish...\n");
for (lots_of_threads = NUM_THREADS - 1; lots_of_threads >= 0; lots_of_threads--) {
res = pthread_join(a_thread[lots_of_threads], &thread_result);
if (res == 0) {
printf("Picked up a thread[%d]\n", lots_of_threads);
}
else {
perror("pthread_join failed");
}
}
double finish_time = getDoubleTime();
printf("All done\n");
// check();
printf("Execute Time: %.3lf ms\n", (finish_time - start_time));
exit(EXIT_SUCCESS);
}
void *thread_function(void *arg) {
int my_number = (long)arg;
int i, j, k;
printf("Thread Number[%d]\n", my_number);
for (i = (MSIZE / NUM_THREADS) * my_number; i < ((MSIZE / NUM_THREADS) * my_number) + (MSIZE / NUM_THREADS); i++) {
for (j = 0; j < MSIZE; j++) {
for (k = 0; k < MSIZE; k++)
C[i][j] += A[i][k] * B[k][j];
printf("C[%d][%d]:{ %d } = A[%d][%d]:{ %d } * B[%d][%d]:{ %d }\n", i, j, C[i][j], i, j, A[i][j], i, j, B[i][j]);
}
}
pthread_exit(NULL);
}
static double getDoubleTime() {
struct timeval tm_tv;
gettimeofday(&tm_tv, 0);
return (double)(((double)tm_tv.tv_sec * (double)1000. + (double)(tm_tv.tv_usec)) * (double)0.001);
}
/*
void check() {
int i, j, k;
int count = 0;
for (i = 0; i < MSIZE; i++) {
for (j = 0; j < MSIZE; j++) {
for (k = 0; k < MSIZE; j++)
D[i][j] += A[i][k] * B[k][j];
}
}
for (i = 0; i < MSIZE; i++) {
for (j = 0; j < MSIZE; j++) {
if ((D[i][j] - C[i][j]) != 0) {
count++;
printf("Error[%d][%d] = [%d]\n", i, j, D[i][j] - C[i][j]);
}
}
}
printf("Different = [%d]\n", count);
}
- 執行結果


Button styles can be applied to any element. Typically you'll want to
use either a <button>
or an
element: This is also an example of using htmlexampletable to render a tabular layout in the styleguide. Leaving a line break will create a new row.
|
|
<button class="btn btn-primary">Click Me</button>
|
|---|---|
Click Me!
|


Definition at line 503 of file btConvexHullComputer.cpp.
◆ ~Edge()
| btConvexHullInternal::Edge::~Edge |
( |
| ) |
|
|
inline |
◆ link()
| void btConvexHullInternal::Edge::link |
( |
Edge * |
n | ) |
|
|
inline |
◆ copy
| int btConvexHullInternal::Edge::copy |
◆ face
| Face* btConvexHullInternal::Edge::face |
◆ next
| Edge* btConvexHullInternal::Edge::next |
◆ prev
| Edge* btConvexHullInternal::Edge::prev |
◆ reverse
| Edge* btConvexHullInternal::Edge::reverse |
◆ target
| Vertex* btConvexHullInternal::Edge::target |
The documentation for this class was generated from the following file:


An error occurred.
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About Us
My name is Matthew Brown. Before coming to codefellows I worked as a manager at a lawfirm specializing in creditor's rights. I am now a software developer and I find that it is far more inline with my love for puzzles and language learning and software deleopment will better showcase my curiosity and ability to adapt to challenges.
Hi, my name is Tom North and I grew up in the great state of Washington in the great city of Puyallup. I came to Seattle to attend the University of Washington and upon graduation I decided to keep Seattle as my home. I'm attending Code Fellows to develop the skills to become a software developer that makes a positive difference in the community and the industry.
I'm Brandon, a software developer in the Seattle area. I like learning foreign languages, practicing martial arts, and competitive gaming. I discovered a love for logic, data, and semantic structure while I was in the Air Force, and have been working to hone my skills ever since.
My name is Andrew Helmer. Prior to coming to codefellows I grew up in St. Landry Louisiana and Kingwood Texas. When I'm not coding I love to hang out with my dog, go fishing, play sports, and play video games. I plan on using the skills I learned during this project to improve myself moving forward.