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• Language/tech specific books which improve vendor-neutral development skills

  - by dotnetdev

  If I ask what the following books have in common: "Accelerated C# 2010, C# in Depth, Pro C# 2008", the answer would be that they would help me to improve my understanding of C# and secondly, my general coding skills. What language-specific/tech-specific books (like those named above) would teach me a great deal about general programming techniques and good habits? I'm thinking Java books would be very good for me (I code in C# primarily), as both these languages are similar and so I am sure that specialist books on Java threading, performance tuning, etc, can be applied to C# (not all 100% content of a Java book). Thanks

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• Looking for calculator source code, BSD-licensed

  - by Horace Ho

  I have an urgent project which need many functions of a calculator (plus a few in-house business rule formulas). As I won't have time to re-invent the wheel so I am looking for source code directly. Requirements: BSD licensed (GPL won't help) in c/c++ programming language 32-bit CPU minimum dependency on platform API/data structure best with both RPN and prefix notation supported emulator/simulator code also acceptable (if not impossible to add custom formula) with following functions (from wikipedia) Scientific notation for calculating large numbers floating point arithmetic logarithmic functions, using both base 10 and base e trigonometry functions (some including hyperbolic trigonometry) exponents and roots beyond the square root quick access to constants such as pi and e plus hexadecimal, binary, and octal calculations, including basic Boolean math fractions optional statistics and probability calculations complex numbers programmability equation solving

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• A strong case for WF

  - by Pita.O

  Hi guys, I have struggled for so long to find a compelling use case for workflow (ie: WF) as against regular imperative programming. Each time I fall back to the conclusion that I should just leave WF out or defer getting into it until later. But I keep having this nagging feeling that there's something am missing. Does anyone know any book that truly makes a strong case for the Workflow way? The book has to (i) teach WF well, and (ii) show using appropriate use cases that WF made an implementation easy to do than if we just did our regular straight coding. I will appreciate it.

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• Touchscreen using sound input?

  - by ricardowong

  Hi, i don't really know if it is actually possible, but i believe that it can be made. How possible is it to make a program that recognizes different sound bouncing from the screen and turn it into a position that will obviously be later fed to the mouse. I know that it sounds kind of dumb, but lately i've been noticing that a very dull, strong sound is made when touching the screen, and that sound varies when doing so at different positions. Probably the microphone "hears" differently because the screen acts as a drum with the casing. Anyways, what do you think, anyone has any experience programming with sound?

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• How significant is the bazaar performance factor?

  - by memodda

  I hear all this stuff about bazaar being slower than git. I haven't used too much distributed version control yet, but in Bazaar vs. Git on the bazaar site, they say that most complaints about performance aren't true anymore. Have you found this to be true? Is performance pretty much on par now? I've heard that speed can affect workflow (people are more likely to do good thing X if X is fast). What specific cases does performance currently affect workflow in bazaar vs other systems (especially git), and how? I'm just trying to get at why performance is of particular importance. Usually when I check something in or update it, I expect it to take a little while, but it doesn't matter. I commit/update when I have a second, so it doesn't interfere with my productivity. But then I haven't used DVCS yet, so maybe that has something to do with it?

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• Does anyone know of a library in Java that can parse ESRI Shapefiles?

  - by KingNestor

  I'm interested in writing a visualization program for the road data in the 2009 Tiger/Line Shapefiles. I'd like to draw the line data to display all the roads for my county. The ESRI Shapefile or simply a shapefile is a popular geospatial vector data format for geographic information systems software. It is developed and regulated by ESRI as a (mostly) open specification for data interoperability among ESRI and other software products.1 A "shapefile" commonly refers to a collection of files with ".shp", ".shx", ".dbf", and other extensions on a common prefix name (e.g., "lakes.*"). The actual shapefile relates specifically to files with the ".shp" extension, however this file alone is incomplete for distribution, as the other supporting files are required. Does anyone know of existing libraries for parsing and reading in the line data for Shapefiles?

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• iPhone Foundation - performance implications of mutable and xxxWithCapacity:0

  - by Adam Eberbach

  All of the collection classes have two versions - mutable and immutable, such as NSArray and NSMutableArray. Is the distinction merely to promote careful programming by providing a const collection or is there some performance hit when using a mutable object as opposed to immutable? Similarly each of the collection classes has a method xxxxWithCapacity, like [NSMutableArray arrayWithCapacity:0]. I often use zero as the argument because it seems a better choice than guessing wrongly how many objects might be added. Is there some performance advantage to creating a collection with capacity for enough objects in advance? If not why isn't the function something like + (id)emptyArray?

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• How to check misspelled email during user registration

  - by Nulldevice

  I use an email registration and confirmation in my project (yes, I know about OpenID. In my counry, a main email service lack it). Sometimes users misspell their email addresses. I know about this due to "message could not be delivered" letters in a mailbox. A misspelled address is absolutely correct, because I check it with a regular expression - say, [email protected] intstead of [email protected]. And I do not want to duplicate a email field in a registration form (who likes it?). Request processing routine cannot wait for email delivery - it could take an unpredictable time. So, my script will return to user a confirmation message "An email was sent". And the user will wait for it forever (of cause, not - he/she will turn to an alternative project with a more perfect registration system). Does someone knows how it can be improved (in any programming language)?

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• displaying web pages over web views in collection view using cocoa bindings

  - by Miraaj

  Hi all, I tried sample example given at this link - Collection View Programming Guide It is simple and it worked. Considering it as a reference I tried a simple application which will show a collection view of web views with some web page displayed over each web view. The model class has two properties: NSString *pageName, and NSURL *pageURL. I then followed each and every step written in tutorial above with required modifications but I was caught in the step - How to bind web view to collection view item? In binding tab it shows three possibilities : Editable, Hidden, Tool tip but none of these is working. Can anyone suggest me way to accomplish my requirement? Thanks, Miraaj

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• Distributing APNS providers

  - by Sam

  I'm writing a business-focused iPhone app which includes a self-hosted server component. I'd like to include push notification functionality in the server; reading through the programming guide it looks as if this would involve either: Distributing the provider certificate with the server component - this doesn't sound like a terribly good idea (even if Apple permits it?) Hosting a shared notification provider and forwarding notifications to APNS from the servers. For an ongoing, high-availability service, this is likely to require including a subscription pricing component, which I would prefer to avoid. Require customers to apply for their own provider certificate. However, it's not clear whether multiple organisations are allowed to apply for provider certificates with a single bundle ID, and it would significantly increase the barrier to adoption. APNS looks to me as if it's specifically geared for centrally hosted services. Is anyone distributing self-hosted notification providers? Are there any other options?

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• Php character coding

  - by out_sider

  I have a file named index.php which using a mysql server gets a simple username. The mysql server is running on centOS and I have two different systems running apache serving as web servers. One is my own windows pc using a "wamp" solution which uses the mysql server refereed before and the other is the centOS server itself. I use this so I can develop in my laptop and run the final on the centOS box. The problem is this: Accessing centOS box I get (on hxxp://centos): out_sider 1lu?s 2oi Using wamp on windows I get (on hxxp://localhost): out_sider 1luís 2oi The mysql database is configured correctly seeing that both use the same and I used svn repository to move files from windows to centOS so the file is the same. Does anyone have any suggestions? Thanks in advnce

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• SQlite: Column format for unix timestamp; Integer types

  - by SF.

  Original problem: What is the right column format for a unix timestamp? The net is full of confusion: some posts claim SQLite has no unsigned types - either whatsoever, or with exception of the 64bit int type (but there are (counter-)examples that invoke UNSIGNED INTEGER). The data types page mentions it only in a bigint example. It also claims there is a 6-byte integer but doesn't give a name for it. Of course standard INTEGER being 4-byte signed signed stores unix timestamps as negative numbers. I've heard that some systems return 64-bit timestamps too. OTOH I'm not too fond of wasting 4 bytes to store 1 extra bit (top bit of timestamp), and even if I have to pick a bigger data format, I'd rather go for the 6-byte one. I've even seen a post that claims SQLite unix timestamp is of type REAL... Complete problem: Could someone please clarify that mess?

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• SCM/VCS: Tracking directories

  - by Roger Pate

  When I first found out that Mercurial tracked files and not directories, I was a bit disappointed. (This means you can't represent an empty directory in the repo.) However, it doesn't seem to be an issue in practice, and makes some things a tad easier for me. How about other SCM systems? (Edit this post to add them.) What advantages or disadvantages have you found by not tracking directories? (Each one separately in an answer, please.) Do track directories: Subversion Bazaar/bzr (add one!) Do NOT track directories: Mercurial/hg git (add one!)

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• Looking for programs on audio tape/cassette containing programs for Sinclair Z80 PC?

  - by DVK

  OK, so back before ice age, I recall having a Sinclair ZX80 PC (with TV as a display, and a cassette tape player as storage device). Obviously, the programs on cassette tapes made a very distinct sound (er... noise) when playing the tape... I was wondering if someone still had those tapes? The reason (and the reason this Q is programming related) is that IIRC different languages made somewhat different pitched noises, but I would like to run the tape and listen myself to confirm if that was really the case...

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• What way to use the CGContext to draw is suitable?

  - by Tattat

  I know that the CGContext cannot call it to draw directly, and it needs to fill the drawing logic in the drawInContext, and call the CGContext to draw using "setNeedsDisplay", so, I designed a cmd to execute, but it cause some problems... like this : http://stackoverflow.com/questions/2617827/why-i-cant-draw-in-a-loop-using-uiview-in-iphone I think the CGContext is very different from my previous programming experience....(I used HTML5 canvas, that allow me add more details, after I draw, so do the Java Swing) Actually, I want to know what is the suitable to implement these kind of thing in Apples' programmer mind. Thz.

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• posix pthreads in c

  - by Codenotguru

  Iam new to c programming and needs some help. long *taskids[NUM_THREADS]; for(t=0; t<NUM_THREADS; t++) { taskids[t] = (long *) malloc(sizeof(long)); *taskids[t] = t; printf("Creating thread %ld\n", t); rc = pthread_create(&threads[t], NULL, PrintHello, (void *) taskids[t]); ... } This code fragment demonstrates how to pass a simple integer to each thread. The calling thread uses a unique data structure for each thread, insuring that each thread's argument remains intact throughout the program. Iam not able to understand how this is happening can somebody explain it??

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• Storing and comparing biometric information

  - by Chathuranga Chandrasekara

  I am not sure whether this is the best place to post this. But this is strongly related with programming so decided to put this here. In general we use biometrics in computer applications say for authentication. Lets get 2 examples finger prints and facial recognition. In those cases how we keep the information for comparison. As an example we can't keep a image and process it every time. So what are the methodologies we use to store/determine the similarity in such cases? Are there any special algorithms that designed for that purposes.? (Ex : To return a approximately equal value for a finger print of a certain person every time)

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• How to sketch out an event-driven system?

  - by Jordan

  I'm trying to design a system in Node.js (an attempt at solving one of my earlier problems, using Node's concurrency) but I'm running into trouble figuring out how to draw a plan of how the thing should operate. I'm getting very tripped up thinking in terms of callbacks instead of returned values. The flow isn't linear, and it's really boggling my ability to draft it. How does one draw out an operational flow for an event-driven system? I need something I can look at and say "Ok, yes, that's how it will work. I'll start it over here, and it will give me back these results over here." Pictures would be very helpful for this one. Thanks. Edit: I'm looking for something more granular than UML, specifically, something that will help me transition from a blocking and object-oriented programming structure, where I'm comfortable, to a non-blocking and event driven structure, where I'm unfamiliar.

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• Android WakeLock and KeyGuard

  - by KimAMartinsen

  Hi! I'm just wondering if I do this correctly; I'm programming a notification app which can display a notification when the phone is sleeping Disable keyguard lock Aquire a wake lock show notification Set alarm for timeout and reenabling keyguard and release wakelock is the user dont touches the screen. 4.1 User touches the screen, and I disable the timer. Do nothing more. Done and done 4.2 User dont touch the screen, so reenable keyguard and release wakelock. Phone sleeps again Basically I'm wondering about point 4.1 the most. cancel the pendingintent for the alarm, and do nothing more? or should the keyguard and wakelock that are set be dealt with in some way?

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• What's the best way to explain parsing to a new programmer?

  - by Daisetsu

  I am a college student getting my Computer Science degree. A lot of my fellow students really haven't done a lot of programming. They've done their class assignments, but let's be honest here those questions don't really teach you how to program. I have had several other students ask me questions about how to parse things, and I'm never quite sure how to explain it to them. Is it best to start just going line by line looking for substrings, or just give them the more complicated lecture about using proper lexical analysis, etc. to create tokens, use BNF, and all of that other stuff? They never quite understand it when I try to explain it. What's the best approach to explain this without confusing them or discouraging them from actually trying.

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• What's the thought behind Children and Controls properties in WPF?

  - by Mathias Lykkegaard Lorenzen

  I don't know if this should go on Programmers, but I thought it was relevant here. Being a skilled WPF programmer myself, I often wonder what people were thinking when they designed WPF in terms of naming conventions. Why would you sometimes have a property called Children for accessing the children of the control, and then sometimes have an equivalent property, just called Controls instead? What were they thinking here? Another example is the Popup control. Instead of a Content property, it has a Child property. Why would you do that? To me that's just confusing. So I'm wondering if there's a logical reason for it, which would probably also help me understand what the properties are called next time I need to do some speed-programming. If there's no reason behind it, then all I can say is WAT.

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• Disable CTRL+P in WPF DocumentViewer

  - by Groupal

  I'm working on a new presenation component for one of our applications. I am building a Custom WPF Control that just has a DocumentViewer in it and hosting that CC in a Windows Forms application with an ElementHost. I'm using Visual Studio 2008 with C#. I have customized everything through the XAML to give it the look and feel that integrates it perfecting into our application, but one thing remains... If you press CTRL+P the print dialog still comes up. I'm at a complete loss as to how to disable that fuction. The use of this CC is to allow the users to pull up and view the Manuals for the systems installed at that site, but we don't want them to accidently print them (100s of pages). Please help, -G

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• Forbidden Not authorized to access this feed

  - by user302593

  Hai, I want to create a sites by using java programming. but it contain error like this... Exception in thread "main" com.google.gdata.util.ServiceForbiddenException: Forbidden Not authorized to access this feed at com.google.gdata.client.http.HttpGDataRequest.handleErrorResponse(HttpGDataRequest.java:561) at com.google.gdata.client.http.GoogleGDataRequest.handleErrorResponse(GoogleGDataRequest.java:563) at com.google.gdata.client.http.HttpGDataRequest.checkResponse(HttpGDataRequest.java:536) at com.google.gdata.client.http.HttpGDataRequest.execute(HttpGDataRequest.java:515) at com.google.gdata.client.http.GoogleGDataRequest.execute(GoogleGDataRequest.java:535) at com.google.gdata.client.Service.getFeed(Service.java:1073) at com.google.gdata.client.Service.getFeed(Service.java:936) at com.google.gdata.client.GoogleService.getFeed(GoogleService.java:631) at com.google.gdata.client.Service.getFeed(Service.java:955) at lsites.getSiteFeed(lsites.java:25) at lsites.main(lsites.java:40) what i want to do? Regards, Bhuvana

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• "TypeError: CreateText() takes exactly 8 arguments (5 given)" with default arguments

  - by Eli Nahon

  def CreateText(win, text, x, y, size, font, color, style): txtObject = Text(Point(x,y), text) if size==None: txtObject.setSize(12) else: txtObject.setSize(size) if font==None: txtObject.setFace("courier") else: txtObject.setFace(font) if color==None: txtObject.setTextColor("black") else: txtObject.setTextColor(color) if style==None: txtObject.setStyle("normal") else: txtObject.setStyle(style) return txtObject def FlashingIntro(win, numTimes): txtIntro = CreateText(win, "CELSIUS CONVERTER!", 5,5,28) for i in range(numTimes): txtIntro.draw(win) sleep(.5) txtIntro.undraw() sleep(.5) I'm trying to get the CreateText function to create a text object with my "default" values if the parameters are not used. (I've tried it with blank strings "" instead of None and no luck) I'm fairly new to Python and have little programming knowledge.

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• How to write Asynchronous LINQ query?

  - by Morgan Cheng

  After I read a bunch of LINQ related stuff, I suddenly realized that no articles introduce how to write asynchronous LINQ query. Suppose we use LINQ to SQL, below statement is clear. However, if the SQL database responds slowly, then the thread using this block of code would be hindered. var result = from item in Products where item.Price > 3 select item.Name; foreach (var name in result) { Console.WriteLine(name); } Seems that current LINQ query spec doesn't provide support to this. Is there any way to do asynchronous programming LINQ? It works like there is a callback notification when results are ready to use without any blocking delay on I/O.

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