Nsyght - davidar's last updates

Why is it so? - Features - The Lab - Australian Broadcasting Corporation's Gateway to Science

Sat, 22 Nov 2008 06:54:46 GMT

Why is it so? - the ground-breaking TV series with the enigmatic Professor Julius Sumner Miller - ran on the ABC from 1963 to 1986. Professor Miller's infectious enthusiasm for physics delighted, educated and entertained generations of Australians, most of whom have at some point asked each other 'Why is it so?' in the characteristic Julius Sumner Miller voice. The Lab has found some of the funniest, most entertaining segments from the Why is it so? series, and made them available for twenty first century enjoyment - over both dialup or broadband connections. Now you too can watch some 'enchanting experiments' with the good professor!
Submited by davidar 22, November 2008

Machine prose

Sat, 22 Nov 2008 06:54:46 GMT

Given a piece of text in any language, the program called ADIOS - automatic distillation of structure - searches for patterns and structures which it then generalises to produce new and meaningful sentences. The ADIOS algorithm is based on statistical and algebraic methods performed on one of the most basic and versatile objects of mathematics - the graph.
Submited by davidar 22, November 2008

Speechless maths

Sat, 22 Nov 2008 06:54:46 GMT

Here you are, reading an article in a magazine about mathematics. This shows that know how to read and that you are interested in maths. But could you still do maths even if you could not make sense of sentences?
Submited by davidar 22, November 2008

The mystery of Zipf

Sat, 22 Nov 2008 06:54:46 GMT

In our recent Plus article Tasty maths, we introduced Zipf's law. Zipf's law arose out of an analysis of language by linguist George Kingsley Zipf, who theorised that given a large body of language (that is, a long book — or every word uttered by Plus employees during the day), the frequency of each word is close to inversely proportional to its rank in the frequency table. That is: $ P_ n \propto 1/n^ a $ where a is close to 1. This is known as a "power law" and suggests that the most frequent word will occur approximately twice as often as the second most frequent word, which occurs twice as often as the fourth most frequent word, etc. A famous study of the Brown Corpus found that its words accorded to Zipf's law quite well, with "the" being the most frequently occurring word (accounting for nearly 7% of all word occurrences — 69,971 out of slightly over 1 million), and "of" the second most frequent (3.5% of all words).
Submited by davidar 22, November 2008

Evolutionary maths

Sat, 22 Nov 2008 06:54:46 GMT

What is it that makes the human mind so unique and us humans so different from the other species we share this planet with? One thing that is universally present throughout human cultures, but absent in all other species, is language. Over the last few decades evolutionary psychologists have become increasingly interested in the role that language might have in enabling other functions in the human behavioural and cognitive repertoire. Some have argued that language is in fact a prerequisite for a whole range of other intellectual activities, including mathematics.
Submited by davidar 22, November 2008

Velocity Reviews - View Single Post - isNumber? check

Sat, 22 Nov 2008 06:54:46 GMT

> How do I check if a value is a number in Python? >>> isinstance(1+1j, (float,int,long,complex)) True
Submited by davidar 22, November 2008

chipmunk-physics - Google Code

Sat, 22 Nov 2008 06:54:46 GMT

Fast 2D rigid body physics library in C
Submited by davidar 22, November 2008

How to Write Your Own IM Bot in Less Than 5 Minutes

Sat, 22 Nov 2008 06:54:46 GMT

This quick tutorial will show you how to develop your own functional IM bot that works with Google Talk, Yahoo! Messenger, Windows Live and all other popular instant messaging clients. To get started, all you need to know are some very basic programming skills (any language would do) and web space to host your “bot”.
Submited by davidar 22, November 2008

AS3 Flash Physics Engine Box2DFlashAS3 2.0.0

Sat, 22 Nov 2008 06:54:46 GMT

Box2DFlashAS3 is an open source port of Erin Catto's powerful c++ physics library Box2D. Cycle through the demos above to see some of the features.
Submited by davidar 22, November 2008

Box2DJS - Physics Engine for JavaScript

Sat, 22 Nov 2008 06:54:46 GMT

Box2DJS is a JavaScript port of Box2D Physics Engine. To tell the truth, this is converted from Box2DFlashAS3_1.4.3.1 in an automatic manner. (The reason why not Box2DFlashAS3_2.0.0 based is simply because I overlooked the renewal.)
Submited by davidar 22, November 2008

How to work with SVN 'tags' and 'branches'

Sat, 22 Nov 2008 06:54:46 GMT

Branching and tagging are concepts common to almost all version control systems. Branch is a separate line of development that exists independently of another line. It always begins life as a copy of something, and moves on from there, generating its own history. Branches are created mainly for the following purposes: independent development of the current revision with the correction support in the release version, long-term independent work, using of source codes of other developers. All three opportunities are shown in the table. There you can also find a more detailed explanation of the algorithm for each opportunity. A tag is just a "snapshot" of a project in time. In Subversion each revision is a snapshot of the repository filesystem after each commit, and it can be used as a tag. But people often want to give some human-friendly names to tags, like release-1.0. Tag is a named snapshot, a symbolical connection with the specified revision of a project. It is generally known that in SVN tags and branches realization is implemented by copying the source code tree to the repository. SVN uses so-called "cheap copies". Instead of making a real copy, the internal link will be created, pointing to a specific tree/revision. As a result branches and tags are very quick to create, and take up almost no extra space in the repository. Actually there's no difference between tags and branches in Subversion. Both are just ordinary directories that are created by copying. The only reason a copied directory is a "tag" (or it is a "branch") is because humans have decided to treat it that way: as long as nobody ever commits to the directory, it forever remains a snapshot. If people start committing to it, it becomes a "branch". Generally, it's not recommended to commit any changes to a tag. If you need to make changes to a tagged release, create a new branch from the tag first and modify the branch.
Submited by davidar 22, November 2008

svn copy

Sat, 22 Nov 2008 06:54:46 GMT

This is the easiest way to “tag” a revision in your repository—just svn copy that revision (usually HEAD) into your tags directory.
Submited by davidar 22, November 2008

no|wrap.de - Flare

Sat, 22 Nov 2008 06:54:46 GMT

Flare processes an SWF and extracts all scripts from it. The output is written to a single text file. Only ActionScript is extracted, no text or images. Flare is freeware. Windows, Mac OS X and Linux versions are available. The main purpose of decompiler is to help you recover your own lost source code. However, there are other uses, like finding out how a component works, or trying to understand poorly documented interface. Depending on where you live, some of them may be forbidden by law. It's your responsibility to make sure you don't break the law using Flare. If you develop Flash applications for living, you probably know that your code is not secure in SWF. It's not the existence of decompiler that makes your code insecure though, it's design of SWF format. Although no ActionScipt is stored there, most of it can be recovered from bytecodes.
Submited by davidar 22, November 2008

Swimbots

Sat, 22 Nov 2008 06:54:46 GMT

What is GenePool? It's a computer simulation where hundreds of virtual organisms evolve swimming skills. These organisms are called "swimbots". You can set mate preference criteria and thus influence what the swimbots consider as attractive qualities in potential mates. The most attractive swimbots get chosen most often to have little babies, and so their genetic building blocks propogate to future generations. Eventually, swimbots get better at pursuing each other, competing for food, and becoming babes to other swimbots. Local gene pools emerge which compete for sex and food (for energy to have more sex). Eventually a dominant sub-population takes over. Sometimes, everyone just dies. That's not a bug. That's nature! If you want, you can move swimbots and food around to help your favorite critters survive. Gene Pool is best appreciated as a virtual Darwinian aquarium in which you initiate a primordial soup, and then occasionally check up on what Virtual Mother Nature is up to - about every fifteen minutes (or every few days, if you are interested in long-term evolutionary experiments!).
Submited by davidar 22, November 2008

Welcome (VLAB)

Sat, 22 Nov 2008 06:54:46 GMT

Welcome to Monash University’s Complexity Virtual Lab (VLAB). VLAB is a web-based resource for research and education about complex systems. Its goals are to stimulate interest in complex systems and Alife and to provide demonstrations, both for key ideas and for recent research findings. VLAB includes numerous simulations (mostly java applets), together with related tutorials, references and web links. The demonstrations include cellular automata, swarms, evolution, networks and non-linear dynamic systems. Applied examples include forest ecology, fire spread, epidemics, starfish outbreaks, spread of computer viruses and cascading power failures.
Submited by davidar 22, November 2008

Java Applets for Neural Network and Artificial Life

Sat, 22 Nov 2008 06:54:46 GMT

Submited by davidar 22, November 2008

code_swarm

Sat, 22 Nov 2008 06:54:46 GMT

I've been studying software projects for a while now. Not the programming, but the people -- the way they interact with each other through collaboration and communication. My investigations have always been visual: I've built applications that create pictures of what is happening within software projects. But they have always had a rigid structure to them. Organic information visualization, coined by Ben Fry, is a different approach to information visualization. It eschews traditional data confinement in space and lets the elements play together in freeform and unpredictable ways. This visualization, called code_swarm, shows the history of commits in a software project. A commit happens when a developer makes changes to the code or documents and transfers them into the central project repository. Both developers and files are represented as moving elements. When a developer commits a file, it lights up and flies towards that developer. Files are colored according to their purpose, such as whether they are source code or a document. If files or developers have not been active for a while, they will fade away. A histogram at the bottom keeps a reminder of what has come before. Please have a look at the videos below. Each one shows a particular software project's evolution. The videos also contain some background information on the projects. The links will take you to Vimeo pages, where a low-quality version can be streamed and viewed in your browser. On those pages, towards the bottom-right, there are also links to download the full quality version of the video.
Submited by davidar 22, November 2008

Linguistics 201: History of English

Sat, 22 Nov 2008 06:54:46 GMT

English belongs to the Germanic Branch of Indo-European English has changed more than most IE languages
Submited by davidar 22, November 2008

Rules and Schemas in the Development and Use of the English past Tense

Sat, 22 Nov 2008 06:54:46 GMT

Consistent error patterns in English past-tense forms are reported for three age groups: preschoolers, 8-10-year-olds, and adults. It is argued that, although irregular forms are rote-learned, speakers make generalizations about such forms. Such a generalization is defined as a SCHEMA which describes general phonological properties of a morphological class, and is used in organizing and accessing the lexicon. Schemas for the English past tense develop and change with age, yielding implications for both acquisitional and diachronic theory
Submited by davidar 22, November 2008

Linguistics: An invisible hand

Sat, 22 Nov 2008 06:54:46 GMT

Quantitative relationships between how frequently a word is used and how rapidly it changes over time raise intriguing questions about the way individual behaviours determine large-scale linguistic and cultural change. In the eighteenth and nineteenth centuries, linguistics was considered a thoroughly historical science, focusing on how languages such as English or Sanskrit changed through time. By uncovering rules governing phonological change, historical linguists reconstructed dead protolanguages such as Indo-European — an ancestral dialect spoken some 10,000 years ago that diverged into a wide variety of modern languages, including Hindi, Russian, Spanish, English and Gaelic.
Submited by davidar 22, November 2008

Frequency of word-use predicts rates of lexical evolution throughout Indo-European history

Sat, 22 Nov 2008 06:54:46 GMT

Greek speakers say "´‘oura", Germans "schwanz" and the French "queue" to describe what English speakers call a 'tail', but all of these languages use a related form of 'two' to describe the number after one. Among more than 100 Indo-European languages and dialects, the words for some meanings (such as 'tail') evolve rapidly, being expressed across languages by dozens of unrelated words, while others evolve much more slowly—such as the number 'two', for which all Indo-European language speakers use the same related word-form1. No general linguistic mechanism has been advanced to explain this striking variation in rates of lexical replacement among meanings. Here we use four large and divergent language corpora (English2, Spanish3, Russian4 and Greek5) and a comparative database of 200 fundamental vocabulary meanings in 87 Indo-European languages6 to show that the frequency with which these words are used in modern language predicts their rate of replacement over thousands of years of Indo-European language evolution. Across all 200 meanings, frequently used words evolve at slower rates and infrequently used words evolve more rapidly. This relationship holds separately and identically across parts of speech for each of the four language corpora, and accounts for approximately 50% of the variation in historical rates of lexical replacement. We propose that the frequency with which specific words are used in everyday language exerts a general and law-like influence on their rates of evolution. Our findings are consistent with social models of word change that emphasize the role of selection, and suggest that owing to the ways that humans use language, some words will evolve slowly and others rapidly across all languages.
Submited by davidar 22, November 2008

Quantifying the evolutionary dynamics of language

Sat, 22 Nov 2008 06:54:46 GMT

Human language is based on grammatical rules1, 2, 3, 4. Cultural evolution allows these rules to change over time5. Rules compete with each other: as new rules rise to prominence, old ones die away. To quantify the dynamics of language evolution, we studied the regularization of English verbs over the past 1,200 years. Although an elaborate system of productive conjugations existed in English's proto-Germanic ancestor, Modern English uses the dental suffix, '-ed', to signify past tense6. Here we describe the emergence of this linguistic rule amidst the evolutionary decay of its exceptions, known to us as irregular verbs. We have generated a data set of verbs whose conjugations have been evolving for more than a millennium, tracking inflectional changes to 177 Old-English irregular verbs. Of these irregular verbs, 145 remained irregular in Middle English and 98 are still irregular today. We study how the rate of regularization depends on the frequency of word usage. The half-life of an irregular verb scales as the square root of its usage frequency: a verb that is 100 times less frequent regularizes 10 times as fast. Our study provides a quantitative analysis of the regularization process by which ancestral forms gradually yield to an emerging linguistic rule.
Submited by davidar 22, November 2008

A Concise Dictionary of Middle English

Sat, 22 Nov 2008 06:54:46 GMT

Submited by davidar 22, November 2008

Children's Overregularization and Its Implications for Cognition

Sat, 22 Nov 2008 06:54:46 GMT

A central goal for cognitive science is to discover basic computational mechanisms that are recruited throughout cognition (Gallistel, 1994). In this paper I propose two mechanisms which underlie learning and generalization. In particular, I propose that humans have both a statistical mechanism which extracts, collects, and tabulates statistical contingencies in the environment, and a rule mechanism which suppresses variation between examples within a category, thereby treating all instances of a category as equal members. Of course, neither mechanism is entirely novel; indeed, much of the debate in cognitive psychology concerns such mechanisms. My goal here is to argue that both mechanisms are necessary. Section 2 presents detailed arguments that argue for the existence of both mechanisms within a single narrow linguistic domain, inflection. Section 3 proposes that these same two types of mechanisms are used in many other domains of cognition.
Submited by davidar 22, November 2008

PubChem Data Directory

Sat, 22 Nov 2008 06:54:46 GMT

This directory contains the sub-directories containing PubChem data in various file formats. Substance - Contains the Substance information Compound - Contains the Compound information BioAssay - Contains the BioAssay descriptions and data specifications - Contains the data specifications and SD tag descriptions Compound_3D - Contains theoretical 3D descriptions of PubChem Compounds :-= Fair Use Disclaimer =-: Databases of molecular data on the NCBI FTP site include such examples as nucleotide sequences (GenBank), protein sequences, macromolecular structures, molecular variation, gene expression, and mapping data. They are designed to provide and encourage access within the scientific community to sources of current and comprehensive information. Therefore, NCBI itself places no restrictions on the use or distribution of the data contained therein. However, some submitters of the original data may claim patent, copyright, or other intellectual property rights in all or a portion of the data they have submitted. NCBI is not in a position to assess the validity of such claims and, therefore, cannot provide comment or unrestricted permission concerning the use, copying, or distribution of the information contained in the molecular databases.
Submited by davidar 22, November 2008

» Connecting to a Bigpond/GA Ubuntu Repository Nuggy’s Blog: Linux, and other things…

Sat, 22 Nov 2008 06:54:45 GMT

So, this is probably old hat to most people, but just incase there is anyone out there starting out on Ubuntu and is in my situation (Crappy Internet, low cap etc etc) this might useful. Bigpond has finally put an Ubuntu Repository on its Game Arena servers, which means it is available as free download for Bigpond users (except Cable Users I think) They mirror everything by multiverse for Hardy Heron and Gutsy Gibbon (Commonly known as 7.10 and 8.04) and as far as I can tell they haven’t got mirrors for any other distributions.
Submited by davidar 22, November 2008

Speed up Internet & Google Earth - Ubuntu Forums

Sat, 22 Nov 2008 06:54:45 GMT

This isn't anything new or my idea, I found it while searching through some of the old ubuntuforums posts. It worked for me, it may work for you too. Basically you disable ipV6 which apparently conflicts with ipV4, I'm no expert on the whys or hows but like I said, it worked for me.
Submited by davidar 22, November 2008

Pygments — Python syntax highlighter

Sat, 22 Nov 2008 06:54:45 GMT

This is the home of Pygments. It is a generic syntax highlighter for general use in all kinds of software such as forum systems, wikis or other applications that need to prettify source code.
Submited by davidar 22, November 2008

Modeling Titration Curves

Sat, 22 Nov 2008 06:54:45 GMT

Titration is a procedure used by chemists to determine the concentrations of dissolved chemical species. Chemistry teachers often use titrations to teach about acid/base behavior. The chemistry teacher uses the shapes of titration curves when explaining a variety of chemical behaviors. What a chemistry teacher describes as the buffering zone and the equivalence point of a titration curve, the mathematics teacher describes as critical points of a function. The titration curve represents a possible area for integration when teaching these two disciplines. We have developed a simple calculator program that generates a titration curve for any reacting acid species with a strong base (such as sodium hydroxide). The user enters these quantities: molarity of acid; dissociation constant for the acid (Ka); dissociation constant for water (Kw); volume of acid to be titrated; and molarity of titrant (such as NaOH). The calculator then generates a titration curve plotting pH vs. volume titrant added. Ka = 100 Ka = 1x10^-5 Ka = 1x10^-10 1. Ka = 100 2. Ka = 1x10^-5 3. Ka = 1x10^-10 PROGRAMS FOR DOWNLOADING The following programs are UUE encoded. TI-82 TI-83 Program for creating titration curves. TITRATE.82P.sit MAC TITRATE.82P.zip WIN TITRATE.82P.sit MAC TITRATE.83p.zip WIN Program written for calculation of first and second derivative of a titration curve. Written by Vernier Software. DERIVE.82p.sit MAC DERIVE.82p.zip WIN DERIVE.83p.sit MAC DERIVE.83p.zip WIN
Submited by davidar 22, November 2008

Activity (chemistry) - Wikipedia, the free encyclopedia

Sat, 22 Nov 2008 06:54:45 GMT

Activity in chemistry is a measure of an “effective concentration” of a species.
Submited by davidar 22, November 2008

pH of any acid/base solution

Sat, 22 Nov 2008 06:54:45 GMT

Submited by davidar 22, November 2008

Acid-Base Titration Curves

Sat, 22 Nov 2008 06:54:45 GMT

The most important characteristics of a neutralization titration can be summarized in the titration curve (usually pH as a function of volume Vtitr of the titrant). The titration curve can be calculated theoretically, whereupon conclusion can be drawn from it for the feasibility and the expected accuracy of a titration, and the selection of the proper protolytic indicator. The most common approach for the calculation of titration curves is based on approximations depending on the relative strength of the acid and base, the concentration levels, and the actual region of the titration curve relatively to the equivalence point. Unfortunately, there is no explicit function of the type [H+] = F(Vtitr), that can be used for the straightforward calculation of the titration curve, but an implicit function of the type F([H+], Vtitr) = 0 can be readily obtained. This function is exact and valid over the entire titration curve for any acid-base system and at any concentration level. The only problem is that due to the complexity of this function a numerical procedure is required to calculate [H+] at a given volume of titrant Vtitr, a task that can be easily accomplished by a computer.
Submited by davidar 22, November 2008

pH Calculations

Sat, 22 Nov 2008 06:54:45 GMT

This page is a drill and practice exercise in basic pH calculations. When you press "New Problem" a value will appear in one of the windows. You must properly fill in the other three windows. Pressing "Check Answer" does so and returns the result in the second table. If you get a problem incorrect, you should retry it until it is correct. Use the "e" notation to enter numbers in scientific notation:
Submited by davidar 22, November 2008

EditArea

Sat, 22 Nov 2008 06:54:45 GMT

Here is EditArea, a free javascript editor for source code. (That is no way a WYSIWYG editor). This editor is designed to edit souce code files in a textarea. The main goal is to allow text formatting, search and replace and real-time syntax highlight (for small text). This editor is free and freely distributable (released under LGPL license). All I ask is that I receive credit for my work. I will also enjoy to receive mail to tell me if you 're using it, just in order to have an idea of how much this editor is used. ;-)
Submited by duck1123 22, November 2008

Project PHYSNET PDF Modules as of 5/15/03

Sat, 22 Nov 2008 06:54:45 GMT

Submited by davidar 22, November 2008

Aim@Shape Project - Shape Repository

Sat, 22 Nov 2008 06:54:45 GMT

The AIM@SHAPE Shape Repository is a shared repository populated with a collection of digital shapes. It is an integral part of the e-Science framework of tools and services for modeling, processing and interpreting digital shapes, developed within the AIM@SHAPE project. Our goal is to include a variety of standard test cases and benchmarks, so as to enable efficient prototyping as well as practical evaluation on real-world and large-scale shape models. The emphasis is on `certified shapes' whose properties are additionally reflected in accompanying metadata specifed by shape ontologies developed by the AIM@SHAPE consortium.
Submited by davidar 22, November 2008

The Lab

Sat, 22 Nov 2008 06:54:45 GMT

In the lab you can do hands-on experiments. There are five experiments: * an undamped and undriven pendulum, * a pendulum driven by a sinusoidal force, * a horizontally driven pendulum, * a vertically driven pendulum, * a pendulum with a rotating suspension point. All experiments are realized with Java applets. They should run on any Web browser supporting Java. Sometimes the Java option is switched of. Be sure that it is switch on before running the experiments! Working with the applets should be rather intuitive. Nevertheless, reading the following instructions is recommended.
Submited by davidar 22, November 2008

Mechanical Properties Data

Sat, 22 Nov 2008 06:54:45 GMT

Mechanical - Thermal Properties of Selected Fibres/Matrices
Submited by davidar 22, November 2008

Mathematical Resources: Mathematical Art, Graphics, Chaos and Fractals (Math Links by Bruno Kevius)

Sat, 22 Nov 2008 06:54:45 GMT

Submited by davidar 22, November 2008

Mathematical Art

Sat, 22 Nov 2008 06:54:45 GMT

Submited by davidar 22, November 2008

Levitated | Levitated Daily Source, the good source

Sat, 22 Nov 2008 06:54:45 GMT

Submited by davidar 22, November 2008

Bathsheba Sculpture

Sat, 22 Nov 2008 06:54:45 GMT

Welcome. I'm an artist exploring how math, science and sculpture meet, and this is my gallery and storefront. My work is about life in three dimensions, symmetry and balance, and always finding beauty in geometry. Here you'll find my signature designs in metal, along with 3D laser-etched glass designs including the Milky Way Galaxy and protein structures. Prices are from $20-500, and I do my best to keep it all in stock. Whether you're here to shop, learn about the technology, or just see some unusual art, I hope you enjoy the work!
Submited by davidar 22, November 2008

Fractal poster, 130 megapixels, Fractal 01, Mandelbrot fractals

Sat, 22 Nov 2008 06:54:45 GMT

We employed a modern PC many days to compute a fractal picture with an absolute incredible resolution of more than 3 gigapixels (these are 3000 megapixels). Since no program can handle such a picture size, we have compressed it per SSAA (supersampling antialiasing, the same as in the Fractalizer) to an optical resolution of still over 130 megapixels.
Submited by davidar 22, November 2008

Debugging Bash scripts

Sat, 22 Nov 2008 06:54:45 GMT

When things don't go according to plan, you need to determine what exactly causes the script to fail. Bash provides extensive debugging features. The most common is to start up the subshell with the -x option, which will run the entire script in debug mode. Traces of each command plus its arguments are printed to standard output after the commands have been expanded but before they are executed.
Submited by davidar 22, November 2008

Roulette (curve) - Wikipedia, the free encyclopedia

Sat, 22 Nov 2008 06:54:45 GMT

In the differential geometry of curves, a roulette is a kind of curve, generalizing cycloids, epicycloids, hypocycloids, and involutes. Roughly speaking, it is the curve described by a point (called the generator or pole) attached to a given curve as it rolls without slipping along a second given curve.
Submited by davidar 22, November 2008

Limaçon -- from Wolfram MathWorld

Sat, 22 Nov 2008 06:54:45 GMT

The limaçon is a polar curve of the form r=b+acostheta (1) also called the limaçon of Pascal. It was first investigated by Dürer, who gave a method for drawing it in Underweysung der Messung (1525). It was rediscovered by Étienne Pascal, father of Blaise Pascal, and named by Gilles-Personne Roberval in 1650 (MacTutor Archive). The word "limaçon" comes from the Latin limax, meaning "snail."
Submited by davidar 22, November 2008

What the heck is a preceptor? » Number pages within chapters in LaTeX

Sat, 22 Nov 2008 06:54:45 GMT

In latex, the \numberwithin command allows one to bind one counter with another. A common example is the section counter and the chapter counter. When a new chapter is created, the chapter counter increments, and the section counter is reset. In this scheme, if the last section of chapter 1 is labeled “1.5″, the first section of chapter 2 is labeled “2.1″.
Submited by davidar 22, November 2008

Tiling versus banding techniques for handling big images

Sat, 22 Nov 2008 06:54:45 GMT

> Why do you think that tiles are better than > bands for handling big images? Various reasons, most of them boil down to the fact that for most practical access in frequent situations, you'll need to access fewer tile blocks compared to band blocks of the same memory size. Here are two examples...
Submited by davidar 22, November 2008

Image Tiling

Sat, 22 Nov 2008 06:54:45 GMT

The IDLgrImage object supports tiling, which lets you display images that are too large to be read entirely into memory. For example, some satellite images can be over a gigabyte in size, which is impossible to fit into memory and display as a single unit on a typical computer. However, it can be displayed by segmenting it into smaller, more manageable image tiles.
Submited by davidar 22, November 2008

Handling large images in ivtools drawing editors

Sat, 22 Nov 2008 06:54:45 GMT

First, the image (raster) handling software in an ivtools drawing editor has been optimized beyond the mechanisms of idraw for more efficient zoom-in, by limiting the zooming activity (and hence the virtual memory required) to just the on-screen region. This mechanism kicks in at 4x or greater magnification. In addition, the rendering algorithm switches to using rectangle drawing instead of pix-blitting at higher resolutions like 16x. After that there are four distinct and composable methods for tiling large images in ivtools drawing editors: # on-the-fly tiling # tiling by drawing editor document # internal raster tiling # external raster tiling
Submited by davidar 22, November 2008