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• Aquamacs and IDLWAVE

  - by nicolavianello

  I've just installed the new Aquamacs 2.0 in my Mac Os X 10.6.3 and I'm an happy user of IDLWAVE on Aquamacs for programming in IDL. Unfortunately I run into a problem which I can't understand. I used in my configuration file to put the following (setq idlwave-surround-by-blank t) for the beautiful space around operator. This used to work till Aquamacs 2.0 preview b3 (third beta release) from that on, it stops to work and every time I type an operator (the same for '=' '<' '' etc) I got the following message Debugger entered--Lisp error: (void-variable idlwave-expand-equal) (lambda nil (interactive) (self-insert-command 1) idlwave-expand- equal -1 -1)() call-interactively((lambda nil (interactive) (self-insert-command 1) idlwave-expand-equal -1 -1) nil nil) Any help is welcommed

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• mystified by qr.Q(): what is an orthonormal matrix in "compact" form?

  - by gappy

  R has a qr() function, which performs QR decomposition using either LINPACK or LAPACK (in my experience, the latter is 5% faster). The main object returned is a matrix "qr" that contains in the upper triangular matrix R (i.e. R=qr[upper.tri(qr)]). So far so good. The lower triangular part of qr contains Q "in compact form". One can extract Q from the qr decomposition by using qr.Q(). I would like to find the inverse of qr.Q(). In other word, I do have Q and R, and would like to put them in a "qr" object. R is trivial but Q is not. The goal is to apply to it qr.solve(), which is much faster than solve() on large systems.

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• If OOP makes problems with large projects, what doesn't?

  - by osca

  I learned Python OOP at school. My (good in theory, bad in practice) informatics told us about how good OOP was for any purpose; Even/Especially for large projects. Now I don't have any experience with teamwork in software development (what a pity, I'd like to program in a team) and I don't know anything about scaling and large projects either. Since some time I'm reading more and more about that object-oriented programming has (many) disadvantages when it comes to really big and important projects/systems. I got a bit confused by that as I always thought that OOP helped you keep large amounts of code clean and structured. Now why should OOP be problematic in large projects? If it is, what would be better? Functional, Declarative/Imperative?

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• setNeedsDisplayInRect: paints a white rectangle only

  - by Ion Tichy

  Hi, I'm still a little fresh to CoreGraphics programming, so please bear with me. I'm trying to write an application, which allows the user to rub stuff off an image with the finger. I have the basic functionality nailed down, but the result is sluggish since the screen is redrawn completely every time a touch is rendered. I did some research and found out that I can refresh only a portion of the screen using UIView's setNeedsDisplayInRect: method. This does call drawRect: as expected, however everything I draw in the drawRect: following the setNeedsDisplayInRect: is ignored. Instead, the area in the rect parameter is simply filled with white. No matter what I draw inside, all I end up with is a white rectangle. In essence, this is what I do: 1) when user touches screen, this touch is rendered into a mask 2) when the drawRect: is called, the image is masked with that mask There must be something simple I'm overlooking, surely?

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• How created method with signature as List

  - by London

  Hi all, I'm very new to Java programming language so this is probably dumb question but I have to ask it because I can't figure it out on my own. Here is the deal. I want to create method which extracts certain object type from a list. So the method should receive List as argument, meaning list should contain either Object1 or Object2. I've tried like this : public Object1 extractObject(List<?>){ //some pseudo-code ... loop trough list and check if list item is instance of object one return that instance } The problem with declaring method with List<?> as method argument is that I receive compilation error from eclipse Syntax error on token ">", VariableDeclaratorId expected after this token. How do I set the method signature properly to accept object types either Object1 or Object2 ? Thank you

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• Build Interactive Floor With Projection !?

  - by Synxmax

  Dear Guys I am somehow newbie and sometimes guru , but at this moment i don't have enough time to research My nightmare is , my boss ask me to create an interactive floor ( he just saw in an exhibition ) , he ask me to create one of them instead of buying , i am an actionscript crawler and developer with some skills in java and c# programming , i just made some track motion with a simple web cam , and this idea came to my mind if i can use an infrared or thermographic camera instead of simple camera so i can get better positioning if camera place at top of floor ! Now i just came here to ask you guys is there any resource , tip , help i can know before getting into this deal !? is there any lib or api out to deal with this ?! EVEN, if there is any resource , article from another language c++ , c , .... could help i just didn't have enough time to test lot of ways If you search interactive floors , or interactive floor projection you can find some companies who provide such a thing Thanks in advance ( and sorry for my damn poor english , français could be better :D )

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• Is there a Chrome extension to add mailto links to email addresses?

  - by Martin Burch

  Wait, wait, this is a programming question! I want to build an extension if none exists. Imagine this: you come across a webpage that says "Just send a message to [email protected]" but to actually send the email, you need to highlight the address and then cut and paste it into the recipient field of a new compose window of your email client of choice. Obviously life would be easier if it were simply a mailto: link, so you could click on it and have a new message created automatically. (Or if the page designer had used a form, perhaps ...) I was originally going to ask if there was an extension to enable similar functionality for unlinked twitter @username mentions but I thought this email address problem would be a simpler situation. If you think it would be useless, perhaps I should look at the twitter username problem instead. Thanks for your feedback.

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• Will PHP Die In Web Page Development World?

  - by Morgan Cheng

  I know that PHP is still the most popular web programming language in the world. This question just want to bring some of my concerns about PHP. PHP is naturally bound to C10K problem. Since PHP (generally run in Apache) cannot be event-driven or asynchronous, each HTTP request will occupy at least one thread or process. This makes it resistant to be more scalable. Currently, a lot of web sites (like Facebook) with high performance and scalability still depends on PHP in their front end servers. I suppose it is due to legacy reason. Is it possible that PHP will be replaced by language more suitable for C10K?

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• Python: Data Object or class

  - by arg20

  I enjoy all the python libraries for scraping websites and I am experimenting with BeautifulSoup and IMDB just for fun. As I come from Java, I have some Java-practices incorporated into my programming styles. I am trying to get the info of a certain movie, I can either create a Movie class or just use a dictionary with keys for the attributes. My question is, should I just use dictionaries when a class will only contain data and perhaps almost no behaviour? In other languages creating a type will help you enforce certain restrictions and because of type checks the IDE will help you program, this is not always the case in python, so what should I do? Should I resort to creating a class only when there's both, behaviour and data? Or create a movie class even though it'll probably be just a data container? This all depends on your model, in this particular case either one is fine but I'm wondering about what's a good practice.

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• Set the path for the location of media files in program

  - by Zaheer Boovaji

  I have made a Java Swing Desktop application in Netbeans which can play media files I have put the videos in my workspace resources location and in my java program I am calling those media files using an URL which is something like this: C:/users/Dell/My Documents /NetBeansProjects/Media/src/resources/ MediaFiles/ddd.mpg This works well when I run in my IDE and also i have made Jar for this it works well on my computer but the problem is when i copy this jar file on my friends system the interface is coming but when I click a button to play a media file it says: C:/users/Dell/MyDocuments/NetBeansProjects/Media/src/resources/ MediaFiles/ddd.mpg does not exist So, please provide me a solution of how to set the default path so that when I run a jar file on other systems it should play the media file location I am passing as in my program. How to set the path for the location of media files in program? Update The videos are in the jar file.

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• Are today's young programmers getting wrapped around the axle with patterns and practices?

  - by Robert Harvey

  Recently I have noticed a number of questions on SO that look something like this: I am writing a small program to keep a list of the songs that I keep on my ipod. I'm thinking about writing it as a 3-tier MVC Ruby on Rails web application with TDD, DDD and IOC, using a factory pattern to create the classes and a singleton to store my application settings. Do you think I'm taking the right approach? Do you think that we're handing novice programmers a very sharp knife and telling them, "Don't cut yourself with this"? NOTE: Despite the humorous tone, this is a serious (and programming-related) question.

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• iPhone write to file (alternative directory)

  - by strider2k

  New to iPhone 3.2, Apple introduced File-Sharing support. Details can be found at https://developer.apple.com/iphone/library/releasenotes/General/WhatsNewIniPhoneOS/Articles/iPhoneOS3_2.html#//apple_ref/doc/uid/TP40009337-SW1 . Now, most examples floating around in the web demonstrates writing to the documents directory. What if I want to write files from my app but I don't want the user to be able to see it via iTunes? I'm looking at the Files and Networking section of the iPhone OS Programming Guide and I'm unsure what would be a good alternative to the documents directory for writing files to hide from the user and not be rejected by Apple's review team.

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• How to implement square root and exponentiation on arbitrary length numbers?

  - by tomp

  I'm working on new data type for arbitrary length numbers (only non-negative integers) and I got stuck at implementing square root and exponentiation functions (only for natural exponents). Please help. I store the arbitrary length number as a string, so all operations are made char by char. Please don't include advices to use different (existing) library or other way to store the number than string. It's meant to be a programming exercise, not a real-world application, so optimization and performance are not so necessary. If you include code in your answer, I would prefer it to be in either pseudo-code or in C++. The important thing is the algorithm, not the implementation itself. Thanks for the help.

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• Bash variable kills script execution

  - by Kyle Terry

  Sorry if this is better suited at serverfault, but I think it learns more towards the programming side of things. I have some code that's going into /etc/rc.local to detect what type of touch screen monitor is plugged in and changes out the xorg.conf before launching X. Here is a small snippet: CURRENT_MONITOR=`ls /dev/usb | grep 'egalax_touch\|quanta_touch'` case $CURRENT_MONITOR in '') CURRENT_MONITOR='none' ;; esac If one of those two touch screens is plugged in, it works just fine. If any other monitor is plugged in, it stops at the "CURRENT_MONITOR=ls /dev/usb | grep 'egalax_touch\|quanta_touch'." For testing I touched two files. One before creating CURRENT_MONITOR and one after CURRENT_MONITOR and only file touched before is created. I'm not a bash programmer so this might be something very obvious.

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• resetting the image in an NSView

  - by Josan

  I think this is a very simple question, but I’m new to programming so I may be going about it in a wrong-headed way. I have a basic understanding of Objective-C writing terminal applications and am teaching myself how to use the Cocoa GUI. I understand how to use IBOutlet and IBAction to connect a simple button to a method that will repeatedly send random numbers to a textfield . I understand how to add a NSView file, connect it to a custom view in interface builder and draw a path through random points in the view when the application launches. (I’ve been putting this code inside the - (void)drawRect:(NSRect)dirtyRect method that is declared when the file is created). What I can’t seem to figure out is how to connect a button to an action that will then ‘refresh’ the view – in this case repopulate it with another set of random points connected with a path. Looking at the documentation, I think I should somehow be using – (void) setNeedsDisplay(BOOL)flag but nothing I have tried so far had worked. Please tell me, what am I missing here?

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• What lessons can you learn from software maintanence?

  - by Vasil Remeniuk

  Hello everyone, In the perfect world, all the software developers would work with the cutting edge technologies, creating systems from the scratch. In the real life, almost all of us have to maintain software from time to time (unlucky ones do it on a regular basis). Personally I first 2 years of my career was fixing bugs in the company that no longer exists (it has been taken up by Oracle). And probably the biggest lesson I've learned that time - despite of the pressure, always try to get as much information about the domain as possible (even if it's irrelevant to fixing a specific bug or adding a feature) - abstract domain knowledge doesn't lose value as fast as knowledge about trendy frameworks or methodologies. What lessons have you learned from maintenance?

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• Style of if: to nest or not to nest

  - by Marco

  A colleague of mine and me had a discussion about the following best-practice issue. Most functions/methods start with some parameter checking. I advocate the following style, which avoids nesting. if (parameter one is ugly) return ERROR; if (parameter two is nonsense || it is raining) return ERROR; // do the useful stuff return result; He, who comes from a more functional/logic programming background, prefers the following, because it reduces the number of exit points from the function. if (parameter one is ok) { if (parameter two is ok && the sun is shining) { // do the useful stuff return result } } return ERROR; Which one would you prefer and why?

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• How do you design a database to allow fast multicolumn searching?

  - by Fletcher Moore

  I am creating a real estate search from RETS data, but this is a general question. When you have a variety of columns that you would like the user to be able to filter their search result by, how do you optimize this? For example, http://www.charlestonrealestateguide.com/listings.php has 16 or so optional filters. Granted, he only has up to 11,000 entries (I have the same data), but I don't imagine the search is performed with just a giant WHERE AND AND AND ... clause. Or is this typically accomplished with one giant multicolumn index? Newegg, Amazon, and countless others also have cool & fast filtering systems for large amounts of data. How do they do it? And is there a database optimization reason for the tendency to provide ranges instead of empty inputs, or is that merely for user convenience?

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• The shortest way to convert infix expressions to postfix (RPN) in C

  - by kuszi

  Original formulation is given here (you can try also your program for correctness) . Additional rules: 1. The program should read from standard input and write do standard output. 2. The program should return zero to the calling system/program. 3. The program should compile and run with gcc -O2 -lm -s -fomit-frame-pointer. The challenge has some history: the call for short implementations has been announced at the Polish programming contest blog in September 2009. After the contest, the shortest code was 81 chars long. Later on the second call has been made for even shorter code and after the year matix2267 published his solution in 78 bytes: main(c){read(0,&c,1)?c-41&&main(c-40&&(c%96<27||main(c),putchar(c))):exit(0);} Anyone to make it even shorter or prove this is impossible?

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• Learning OpenGL ES 1.x

  - by Kristopher Johnson

  What is the quickest way to come up to speed on OpenGL ES 1.x? Let's assume I know nothing about OpenGL (which is not entirely true, but it's been a while since I last used OpenGL). I am most interested in learning this for iPhone-related development, but I'm interested in learning how it works on other platforms as well. I've found the book OpenGL ES 2.0 Programming Guide, but I am concerned that it might not be the best approach because it focuses on 2.0 rather than 1.x. My understanding is that 2.0 is not backwards-compatible with 1.x, so I may miss out on some important concepts. Note: For answers about learning general OpenGL, see http://stackoverflow.com/questions/62540/learning-opengl Some resources I've found: http://khronos.org/opengles/1_X/ http://www.imgtec.com/powervr/insider/sdk/KhronosOpenGLES1xMBX.asp OpenGL Distilled by Paul Martz (a good refresher on OpenGL basics)

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• "SQL Server does not exist or access denied." upon VB.Net Deployment

  - by JasonMHirst

  Have built a small VB.Net app in VS2010. The connection string to the SQL Server is as follows: <connectionStrings> <add name="IWSR_DataDownloadWizard.My.MySettings.sqlConnection" connectionString="Provider=SQLOLEDB.1;Data Source=SQLServer;Integrated Security=SSPI;Initial Catalog=IWSROL" providerName="System.Data.OleDb" /> </connectionStrings> Within the VS2010 environment AND on my machine, the connection works perfectly, however when I deploy to clients I get an error message of: [DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied. I've tried to search the net for solutions, have seen a few instances of people saying to NOT use the Server Name but the IP Address instead (this doesn't work) and some saying to remove the "Provider=SQLOLEDB.1", again this doesn't work. Can anyone suggest a solution please? Further information: Development System is Windows7 using VS2010 Deployment systems are a combination of Windows XP, Windows 2000 and Windows 7 SQL Server is SQL2000 (soon to be SQL2005). TIA

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• What Database to distribute as part of a C# app backend

  - by jez

  I am planning on writing and commercialising a C# app which will store data in an underlying database I use MySQL on my environment for my own development and this is what I would have used to write the application for myself (no need to use FK - MyISAM engine would be fine). I am concerned about how easy it will be to distribute the app together with the database engine. Would using MySQL allow me for easy packaging of the app for a "one-click" install on the client side? (ie I do not want them to have to install MySQL by themselves) and also is it feasible from a licensing point of view? Are there other Database systems which would make the process more straight-forward

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• Repeating a List in Scala

  - by Ralph

  I am a Scala noob. I have decided to write a spider solitaire solver as a first exercise to learn the language and functional programming in general. I would like to generate a randomly shuffled deck of cards containing 1, 2, or 4 suits. Here is what I came up with: val numberOfSuits = 1 (List["clubs", "diamonds", "hearts", "spades"].take(numberOfSuits) * 4).take(4) which should return List["clubs", "clubs", "clubs", "clubs"] List["clubs", "diamonds", "clubs", "diamonds"] List["clubs", "diamonds", "hearts", "spades"] depending on the value of numberOfSuits, except there is no List "multiply" operation that I can find. Did I miss it? Is there a better way to generate the complete deck before shuffling? BTW, I plan on using an Enumeration for the suits, but it was easier to type my question with strings. I will take the List generated above and using a for comprehension, iterate over the suits and a similar List of card "ranks" to generate a complete deck.

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• For what programs are Objective C and Ruby ideal on the Mac?

  - by Kurt

  Hi, as a Mac outsider it seems that two popular programming languages on the Mac appear to be Objective C and Ruby. From what I understand the main API Cocoa seems to be written in and optimized for Objective C, but it is also possible to use Ruby for that. Are there different areas where each language is ideal, for example, I could imagine Objective C could be ideal for a GUI layer, or standalone desktop app, and Ruby could be good for web services etc. What about classic business logic, or data access layers? What language would be a good choice for a library of services for example? Can we write a library in one language and link to it from a main program written in the other language? If I wanted to write a layered enterprise application using domain driven design and dependency injection which languages could support each concerns? Are things like DDD and DI common amongst Mac devs? Just a curious outsider.

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• Animate 3D model programmatically-where to start?

  - by amile

  I am having a task to create a 3D model face that can talk like humans.without having any knowledge about 3D modeling. I have no clue where to start.I have searched a lot and find some of these things.OpenGL,WebGL,XNA and other similar tool can be helpful. please guide me where to start a step by step approach and which platform is better as i have programming background in JAVA. here is an idea what I need to do https://docs.google.com/viewer?a=v&pid=gmail&attid=0.2&thid=13f65486a46a1f67&mt=application/pdf&url=https://mail.google.com/mail/?ui%3D2%26ik%3D49f1f393c6%26view%3Datt%26th%3D13f65486a46a1f67%26attid%3D0.2%26disp%3Dsafe%26realattid%3Df_hi6ylzbv2%26zw&sig=AHIEtbQc8KQNHdprmEnL4UXyD3ox8vlKKQ

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