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• How best to deal with warning c4305 when type could change?

  - by identitycrisisuk

  I'm using both Ogre and NxOgre, which both have a Real typedef that is either float or double depending on a compiler flag. This has resulted in most of our compiler warnings now being: warning C4305: 'argument' : truncation from 'double' to 'Ogre::Real' When initialising variables with 0.1 for example. Normally I would use 0.1f but then if you change the compiler flag to double precision then you would get the reverse warning. I guess it's probably best to pick one and stick with it but I'd like to write these in a way that would work for either configuration if possible. One fix would be to use #pragma warning (disable : 4305) in files where it occurs, I don't know if there are any other more complex problems that can be hidden by not having this warning. I understand I would push and pop these in header files too so that they don't end up spreading across code. Another is to create some macro based on the accuracy compiler flag like: #if OGRE_DOUBLE_PRECISION #define INIT_REAL(x) (x) #else #define INIT_REAL(x) static_cast<float>( x ) #endif which would require changing all the variable initialisation done so far but at least it would be future proof. Any preferences or something I haven't thought of?

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• How can I create an Image in GDI+ from a Base64-Encoded string in C++?

  - by Schnapple

  I have an application, currently written in C#, which can take a Base64-encoded string and turn it into an Image (a TIFF image in this case), and vice versa. In C# this is actually pretty simple. private byte[] ImageToByteArray(Image img) { MemoryStream ms = new MemoryStream(); img.Save(ms, System.Drawing.Imaging.ImageFormat.Tiff); return ms.ToArray(); } private Image byteArrayToImage(byte[] byteArrayIn) { MemoryStream ms = new MemoryStream(byteArrayIn); BinaryWriter bw = new BinaryWriter(ms); bw.Write(byteArrayIn); Image returnImage = Image.FromStream(ms, true, false); return returnImage; } // Convert Image into string byte[] imagebytes = ImageToByteArray(anImage); string Base64EncodedStringImage = Convert.ToBase64String(imagebytes); // Convert string into Image byte[] imagebytes = Convert.FromBase64String(Base64EncodedStringImage); Image anImage = byteArrayToImage(imagebytes); (and, now that I'm looking at it, could be simplified even further) I now have a business need to do this in C++. I'm using GDI+ to draw the graphics (Windows only so far) and I already have code to decode the string in C++ (to another string). What I'm stumbling on, however, is getting the information into an Image object in GDI+. At this point I figure I need either a) A way of converting that Base64-decoded string into an IStream to feed to the Image object's FromStream function b) A way to convert the Base64-encoded string into an IStream to feed to the Image object's FromStream function (so, different code than I'm currently using) c) Some completely different way I'm not thinking of here. My C++ skills are very rusty and I'm also spoiled by the managed .NET platform, so if I'm attacking this all wrong I'm open to suggestions.

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• Objective-C / Cocoa: Uploading Images, Working Memory, And Storage.

  - by Finley Still

  Hello. I'm in the process of porting an application originally in java to cocoa, but I'm rewriting it to make it much better, since I prefer cocoa a lot anyway. One of the problems I had in the application, was that when you uploaded images to it, I had the images created, (as say an NSImage object) and then I just had them sitting in memory, the more I uploaded the more memory they took up, and I ended up running out of memory. My question is this: if I am going to have users upload images to this application in cocoa, how should I go about storing them? I don't just want to copy the file paths, because I want what is saved to contain the images, etc. Is there any way to upload an image and copy it into a different place only for my application? Then load that image with the new path name as needed? Only I would like it all to be consolidated. I'm going to implement saving by archiving one "master" object into an NSData*- so I'd like the images to be saved with that. Is there a temporary location maybe where I could write the images to disk for my application, and then when I saved, they would all be archived into a single file? Also, how do I do this? Thanks.

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• Java Swing custom shapes (2D Graphics)

  - by juFo

  I need to draw custom shapes. Now when a user clicks on several points on the panel I create a shape using a polygon. public void mouseClicked(MouseEvent e) { polygon.addPoint(e.getX(), e.getY()); repaint(); } But I don't know if this is the best way to draw custom shapes. It should be possible to edit a drawn shape: resize change its fill color change the stroke color copy/paste it move a single point of the polygon ... I have seen people creating an own class implementing the Shape class and using a GeneralPath. But again I have no idea if this is a good way. Now I can create my own shape with a polygon (or with a GeneralPath) but I have no clue how to attach all the edit functions to my own shape (the edit functions I mean the resize, move, etc from above). I hope somebody could show me a way to do this or maybe write a little bit of code to demonstrate this. Thanks in advance!!

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• Why do I get a security warning in visual studio 2008 when creating a project?

  - by MikeG

  This is the error, it's basically a security warning (And here's the text grabbed off the dialog box) Security Warning for WindowsApplication4 __________________________I The WindowsApplication4 project file has been customized and could present a security risk by executing custom build steps when opened in Microsoft Visual Studio. If this project came from an untrustwoithy source, it could cause damage to your computer or compromise your private information. More Details Project load options 0 Load project for browsing Opens the project in Microsoft Visual Studio with increased security. This option allows you to browse the contents of the project, but some functionality, such as IntelliSense, is restricted, When a project is loaded for browsing, actions such as building, cleaning, publishing, or opening designers could still remain unsafe. Load project normally Opens the project normally in Microsoft Visual Studio. Use this option if you trust the source and understand the potential risks involved. Microsoft Visual Studio does not restrict any project functionality and will not prompt you again for this project. Ask me for every project in this solution OK L Cancel When click the more details button get this: Microsoft Visual Studio __ An item referring to the file was found in the project file “C:\Users\mgriffiths\Documents\Visual Studio 2008\ProjectATemp\Win dowsApplication4\WindowsApplicdtion4\W in dowsApplication4.vbproj”. Since this file is located within a system directory, root directory, or network share, it could be harmful to write to this file. OK

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• How to handle 'this' pointer in constructor?

  - by Kyle

  I have objects which create other child objects within their constructors, passing 'this' so the child can save a pointer back to its parent. I use boost::shared_ptr extensively in my programming as a safer alternative to std::auto_ptr or raw pointers. So the child would have code such as shared_ptr<Parent>, and boost provides the shared_from_this() method which the parent can give to the child. My problem is that shared_from_this() cannot be used in a constructor, which isn't really a crime because 'this' should not be used in a constructor anyways unless you know what you're doing and don't mind the limitations. Google's C++ Style Guide states that constructors should merely set member variables to their initial values. Any complex initialization should go in an explicit Init() method. This solves the 'this-in-constructor' problem as well as a few others as well. What bothers me is that people using your code now must remember to call Init() every time they construct one of your objects. The only way I can think of to enforce this is by having an assertion that Init() has already been called at the top of every member function, but this is tedious to write and cumbersome to execute. Are there any idioms out there that solve this problem at any step along the way?

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• Writing to a new log file each day with TraceSource

  - by Cipher

  I am using a logger in my application to write to files. The source, switch and listeners have been defined in the app.config file as follows: <system.diagnostics> <sources> <source name="LoggerApp" switchName="sourceSwitch" switchType="System.Diagnostics.SourceSwitch"> <listeners> <add name="myListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="myListener.log" /> </listeners> </source> </sources> <switches> <add name="sourceSwitch" value="Information" /> </switches> </system.diagnostics> Inside, my .cs code, I use the logger as follows: private static TraceSource logger = new TraceSource("LoggerApp"); logger.TraceEvent(TraceEventType.Information, 1, "{0} : Started the application", DateTime.Now); What would I have to do to create a new log file each day instead of writing to the same log file every time?

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• CSS to specify positions over a scanned document

  - by itsols

  I'm trying to write the CSS rules to position text over a scanned document. Reason: The document is a pre-printed form. I am trying to position the text on-screen so that it relates to the 'spaces' on the actual form. Issue: Although I position the values using centimeters, they don't seem to get aligned with the ones on the actual page. I can see this misalignment since my scanned image is in the background of the page. What I've tried: I used a ruler to physically measure the locations and specify them with CSS. But on-screen, it doesn't tally. I used the scanned image to position the CSS values. Then the printout is not correct. I even scaled the scanned page using Inkscape to the exact dimensions in centimeters and took into account all margins, etc... What I need: I am trying to correctly show the output values on-screen AND have them print in the correct manner as well. I know that using two CSS sheets (one for print) is an option. But I'm developing this program away from where the actual printing is to be done. So is there a convenient way of matching the exact screen locations with those on the actual/final prinout? Thanks!

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• What good open source programs exist for fuzzing popular image file types?

  - by JohnnySoftware

  I am looking for a free, open source, portable fuzzing tool for popular image file types that is written in either Java, Python, or Jython. Ideally, it would accept specifications for the fuzzable fields using some kind of declarative constraints. Non-procedural grammar for specifying constraints are greatly preferred. Otherwise, might as well write them all in Python or whatever. Just specifying ranges of valid values or expressions for them. Ideally, it would support some kind of generative programming to export the fuzzer into various programming languages to suit cases where more customization was required. If it supported a direct-manipulation GUI for controlling parameter values and ranges, that would be nice too. The file formats that should be supported are: GIF JPEG PNG So basically, it should be sort of a toolkit consisting of ready-to-run utility, a framework or library, and be capable of generating the fuzzed files directly as well as from programs it generates. It needs to be simple so that test images can be created quickly. It should have a batch capability for creating a series of images. Creating just one at a time would be too painful. I do not want a hacking tool, just a QA tool. Basically, I just want to address concerns that it is taking too long to get commonplace image rendering/parsing libraries stable and trustworthy.

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• Programmatically configure MATLAB

  - by Richie Cotton

  Since MathWorks release a new version of MATLAB every six months, it's a bit of hassle having to set up the latest version each time. What I'd like is an automatic way of configuring MATLAB, to save wasting time on administrative hassle. The sorts of things I usually do when I get a new version are: Add commonly used directories to the path. Create some toolbar shortcuts. Change some GUI preferences. The first task is easy to accomplish programmatically with addpath and savepath. The next two are not so simple. Details of shortcuts are stored in the file 'shortcuts.xml' in the folder given by prefdir. My best idea so far is to use one of the XML toolboxes in the MATLAB Central File Exchange to read in this file, add some shortcut details and write them back to file. This seems like quite a lot of effort, and that usually means I've missed an existing utility function. Is there an easier way of (programmatically) adding shortcuts? Changing the GUI preferences seems even trickier. preferences just opens the GUI preference editor (equivalent to File - Preferences); setpref doesn't seems to cover GUI options. The GUI preferences are stored in matlab.prf (again in prefdir); this time in traditional name=value config style. I could try overwriting values in this directly, but it isn't always clear what each line does, or how much the names differ between releases, or how broken MATLAB will be if this file contains dodgy values. I realise that this is a long shot, but are the contents of matlab.prf documented anywhere? Or is there a better way of configuring the GUI? For extra credit, how do you set up your copy of MATLAB? Are there any other tweaks I've missed, that it is possible to alter via a script?

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• How can I go through a Set in JSP? (Hibernate Associations)

  - by Parris

  Hi All, So I am pretty new to JSP. I have tried this a few ways. Ways that would make sense in PHP or automagicy frameworks... I am probably thinking too much in fact... I have a hibernate one to many association. That is class x has many of class y. In class x's view.jsp. I would like to grab all of class y, where the foreign key of y matches the primary key of x and display them. It seems that hibernate properly puts this stuff into a set. Now, the question is how can I iterate through this set and then output it's contents... I am kind of stumped here. I tried to write a scriptlet, <% java.util.Iterator iter = aBean.getYs().iter(); // aBeans is the bean name // getYs would return the set and iter would return an iterator for the set while(iter.hasNext) { model.X a = new iter.next() %> <h1><%=a.getTitle()%></h1> <% } %> It would seem that that sort of thing should work? Hmmmmmm

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• User to kernel mode big picture?

  - by fsdfa

  I've to implement a char device, a LKM. I know some basics about OS, but I feel I don't have the big picture. In a C programm, when I call a syscall what I think it happens is that the CPU is changed to ring0, then goes to the syscall vector and jumps to a kernel memmory space function that handle it. (I think that it does int 0x80 and in eax is the offset of the syscall vector, not sure). Then, I'm in the syscall itself, but I guess that for the kernel is the same process that was before, only that it is in kernel mode, I mean the current PCB is the process that called the syscall. So far... so good?, correct me if something is wrong. Others questions... how can I write/read in process memory?. If in the syscall handler I refer to address, say, 0xbfffffff. What it means that address? physical one? Some virtual kernel one?

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• XSLT for-each from query results

  - by Ben Record

  I've been on a hunt for a while trying to find a solution to this but I cannot find anywhere that addresses this problem. I'm running a SQL query through XSLT which will return three rows. Here is the query: <query name="OrderedProductNames" rowElementName ="OrderedItem"> <sql> <![CDATA[ select OrderedProductName, Quantity from Orders_ShoppingCart where OrderNumber = 101689 // Hard coded order number for testing purposes. ]]> </sql> </query> Ideally, I would like to iterate through each row returned and do a choose when which is tested on a variable from the current row being inspected in the for-each loop, but I am not entirely sure thhis is possible. My secondary thought would be to use the for-each loop as a way to inject hidden HTML input elements with the values I would need, then I could write a javascript function to complete what I'm trying to do. Any suggestion on how I would go about completing either task would be greatly appreciated.

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• How do I DRY up business logic between sever-side Ruby and client-side Javascript?

  - by James A. Rosen

  I have a Widget model with inheritance (I'm using Single-Table Inheritance, but it's equally valid for Class-per-Table). Some of the subclasses require a particular field; others do not. class Widget < ActiveRecord ALL_WIDGET_TYPES = [FooWidget, BarWidget, BazWidget] end class FooWidget < Widget validates_presence_of :color end class BarWidget < Widget # no color field end class BazWidget < Widget validates_presence_of :color end I'm building a "New Widget" form (app/views/widgets/new.html.erb) and would like to dynamically show/hide the color field based on a <select> for widget_type. <% form_for @widget do |f| %> <%= f.select :type, Widget::ALL_WIDGET_TYPES %> <div class='hiddenUnlessWidgetTypeIsFooOrBaz'> <%= f.label :color %> <%= f.text_field :color %> </div> <% end %> I can easily write some jQuery to watch for onChange events on widget_type, but that would mean putting some sort of WidgetTypesThatRequireColor constant in my Javascript. Easy enough to do manually, but it is likely to get disconnected from the Widget model classes. I would prefer not to output Javascript directly in my view, though I have considered using content_for(:js) and have a yield :js in my template footer. Any better ideas?

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• What are the skills a Drupal Developer needs?

  - by hfidgen

  I'm trying to write out a list of key Drupal competencies, mainly so I can confirm what I know, don't know and don't know I don't know. (Thanks D. Rumsfeld for that quote!) I think some of these are really broad, for instance there's quite a difference between making a functional theme and creating a theme with good SEO, load times and so on, but I'm hoping you could assume that a half decent web developer would look after that anyway. Just interested to see what people here feel is also important. Able to install Drupal on a server (pretty obvious). Able to research and install modules to meet project requirements Able to configure all the basic modules and core settings to get a site running Able to create a custom Theme from scratch which validates with good HTML/CSS and also pays attention to usability and accessibility. (Whilst still looking kick-ass). Able to use Hooks in the theme template.php to alter forms, page layout and other core functionality Can make forms from scratch using the API - with validation and posting back to the DB/email Can use Views to create blocks or pages, use php snippets as arguments, etc. Can create custom modules from scratch utilising core hooks and other hooks.

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• NoSQL for filesystem storage organization and replication?

  - by wheaties

  We've been discussing design of a data warehouse strategy within our group for meeting testing, reproducibility, and data syncing requirements. One of the suggested ideas is to adapt a NoSQL approach using an existing tool rather than try to re-implement a whole lot of the same on a file system. I don't know if a NoSQL approach is even the best approach to what we're trying to accomplish but perhaps if I describe what we need/want you all can help. Most of our files are large, 50+ Gig in size, held in a proprietary, third-party format. We need to be able to access each file by a name/date/source/time/artifact combination. Essentially a key-value pair style look-up. When we query for a file, we don't want to have to load all of it into memory. They're really too large and would swamp our server. We want to be able to somehow get a reference to the file and then use a proprietary, third-party API to ingest portions of it. We want to easily add, remove, and export files from storage. We'd like to set up automatic file replication between two servers (we can write a script for this.) That is, sync the contents of one server with another. We don't need a distributed system where it only appears as if we have one server. We'd like complete replication. We also have other smaller files that have a tree type relationship with the Big files. One file's content will point to the next and so on, and so on. It's not a "spoked wheel," it's a full blown tree. We'd prefer a Python, C or C++ API to work with a system like this but most of us are experienced with a variety of languages. We don't mind as long as it works, gets the job done, and saves us time. What you think? Is there something out there like this?

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• gl_FragColor and glReadPixels

  - by chun0216

  I am still trying to read pixels from fragment shader and I have some questions. I know that gl_FragColor returns with vec4 meaning RGBA, 4 channels. After that, I am using glReadPixels to read FBO and write it in data GLubyte *pixels = new GLubyte[640*480*4]; glReadPixels(0, 0, 640,480, GL_RGBA, GL_UNSIGNED_BYTE, pixels); This works fine but it really has speed issue. Instead of this, I want to just read RGB so ignore alpha channels. I tried: GLubyte *pixels = new GLubyte[640*480*3]; glReadPixels(0, 0, 640,480, GL_RGB, GL_UNSIGNED_BYTE, pixels); instead and this didn't work though. I guess it's because gl_FragColor returns 4 channels and maybe I should do something before this? Actually, since my returned image (gl_FragColor) is grayscale, I did something like float gray = 0.5 //or some other values gl_FragColor = vec4(gray,gray,gray,1.0); So is there any efficient way to use glReadPixels instead of using the first 4 channels method? Any suggestion? By the way, this is on opengl es 2.0 code.

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• How to parallelize this groovy code?

  - by lucas

  I'm trying to write a reusable component in Groovy to easily shoot off emails from some of our Java applications. I would like to pass it a List, where Email is just a POJO(POGO?) with some email info. I'd like it to be multithreaded, at least running all the email logic in a second thread, or make one thread per email. I am really foggy on multithreading in Java so that probably doesn't help! I've attempted a few different ways, but here is what I have right now: void sendEmails(List<Email> emails) { def threads = [] def sendEm = emails.each{ email -> def th = new Thread({ Random rand = new Random() def wait = (long)(rand.nextDouble() * 1000) println "in closure" this.sleep wait sendEmail(email) }) println "putting thread in list" threads << th } threads.each { it.run() } threads.each { it.join() } } I was hoping the sleep would randomly slow some threads down so the console output wouldn't be sequential. Instead, I see this: putting thread in list putting thread in list putting thread in list putting thread in list putting thread in list putting thread in list putting thread in list putting thread in list putting thread in list putting thread in list in closure sending email1 in closure sending email2 in closure sending email3 in closure sending email4 in closure sending email5 in closure sending email6 in closure sending email7 in closure sending email8 in closure sending email9 in closure sending email10 sendEmail basically does what you'd expect, including the println statement, and the client that calls this follows, void doSomething() { Mailman emailer = MailmanFactory.getExchangeEmailer() def to = ["one","two"] def from = "noreply" def li = [] def email (1..10).each { email = new Email(to,null,from,"email"+it,"hello") li << email } emailer.sendEmails li }

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• KaZip for C++Builder2009/Delphi

  - by Katsumi

  Hi. I have download and install KaZip2.0 on C++Builder2009 (with little minor changes = only set type String to AnsiString). I have write: KAZip1->FileName = "test.zip"; KAZip1->CreateZip("test.zip"); KAZip1->Active = true; KAZip1->Entries->AddFile("pack\\text.txt","xxx.txt"); KAZip1->Active = false; KAZip1->Close(); now he create a test.zip with included xxx.txt (59byte original, 21byte packed). I open the archiv in WinRAR successful and want open the xxx.txt, but WinRAR says file is corrupt. :( What is wrong? Can somebody help me? Extract not working, because file is corrupt? KAZip1->FileName = "test.zip"; KAZip1->Active = true; KAZip1->Entries->ExtractToFile("xxx.txt","zzz.txt"); KAZip1->Active = false; KAZip1->Close();

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• Which web framework or technologies would suit me?

  - by Suraj Chandran

  Hi, I had been working on desktop apps and server side(non web) for some time and now I am diving in to web first time. I plan to write a scalable enterprise level app. I have worked with Java, Javascript, Jquery etc. but I absolutely hate jsp. So is there any framework that focuses on developing enterprise level web apps without jsp. I liked Wicket's approach, but I think there is a little lack of support of dynamic html in it and jquery(yes i looked at wiquery). Also I feel making wicket apps scalable would take some sweat. Can Spring MVC, Struts2 etc. help me make with this with just using say Java, JavaScript, and JQuery. Or are there any other options for me like Wicket. Please do forgive if anything above looks insane, I am still working on my understanding with enterprise web apps. NOTE: If you think that I should take a different direction or approach, please do suggest!

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• Intel MKL memory management and exceptions

  - by Andrew

  Hello everyone, I am trying out Intel MKL and it appears that they have their own memory management (C-style). They suggest using their MKL_malloc/MKL_free pairs for vectors and matrices and I do not know what is a good way to handle it. One of the reasons for that is that memory-alignment is recommended to be at least 16-byte and with these routines it is specified explicitly. I used to rely on auto_ptr and boost::smart_ptr a lot to forget about memory clean-ups. How can I write an exception-safe program with MKL memory management or should I just use regular auto_ptr's and not bother? Thanks in advance. EDIT http://software.intel.com/sites/products/documentation/hpc/mkl/win/index.htm this link may explain why I brought up the question UPDATE I used an idea from the answer below for allocator. This is what I have now: template <typename T, size_t TALIGN=16, size_t TBLOCK=4> class aligned_allocator : public std::allocator<T> { public: pointer allocate(size_type n, const void *hint) { pointer p = NULL; size_t count = sizeof(T) * n; size_t count_left = count % TBLOCK; if( count_left != 0 ) count += TBLOCK - count_left; if ( !hint ) p = reinterpret_cast<pointer>(MKL_malloc (count,TALIGN)); else p = reinterpret_cast<pointer>(MKL_realloc((void*)hint,count,TALIGN)); return p; } void deallocate(pointer p, size_type n){ MKL_free(p); } }; If anybody has any suggestions, feel free to make it better.

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• Capturing stdout from an imported module in wxpython and sending it to a textctrl, without blocking the GUI

  - by splafe

  There are alot of very similar questions to this but I can't find one that applies specifically to what I'm trying to do. I have a simulation (written in SimPy) that I'm writing a GUI for, the main output of the simulation is text - to the console from 'print' statements. Now, I thought the simplest way would be to create a seperate module GUI.py, and import my simulation program into it: import osi_model I want all the print statements to be captured by the GUI and appear inside a Textctrl, which there's countless examples of on here, along these lines: class MyFrame(wx.Frame): def __init__(self, *args, **kwds): <general frame initialisation stuff..> redir=RedirectText(self.txtCtrl_1) sys.stdout=redir class RedirectText: def __init__(self,aWxTextCtrl): self.out=aWxTextCtrl def write(self,string): self.out.WriteText(string) I am also starting my simulation from a 'Go' button: def go_btn_click(self, event): print 'GO' self.RT = threading.Thread(target=osi_model.RunThis()) self.RT.start() This all works fine, and the output from the simulation module is captured by the TextCtrl, except the GUI locks up and becomes unresponsive - I still need it to be accessible (at the very minimum to have a 'Stop' button). I'm not sure if this is a botched attempt at creating a new thread that I've done here, but I assume a new thread will be needed at some stage in this process. People suggest using wx.CallAfter, but I'm not sure how to go about this considering the imported module doesn't know about wx, and also I can't realistically go through the entire simulation architecture and change all the print statements to wx.CallAfter, and any attempt to capture the shell from inside the imported simulation program leads to the program crashing. Does anybody have any ideas about how I can best achieve this? So all I really need is for all console text to be captured by a TextCtrl while the GUI remains responsive, and all text is solely coming from an imported module. (Also, secondary question regarding a Stop button - is it bad form to just kill the simulation thread?). Thanks, Duncan

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• How to speed-up python nested loop?

  - by erich

  I'm performing a nested loop in python that is included below. This serves as a basic way of searching through existing financial time series and looking for periods in the time series that match certain characteristics. In this case there are two separate, equally sized, arrays representing the 'close' (i.e. the price of an asset) and the 'volume' (i.e. the amount of the asset that was exchanged over the period). For each period in time I would like to look forward at all future intervals with lengths between 1 and INTERVAL_LENGTH and see if any of those intervals have characteristics that match my search (in this case the ratio of the close values is greater than 1.0001 and less than 1.5 and the summed volume is greater than 100). My understanding is that one of the major reasons for the speedup when using NumPy is that the interpreter doesn't need to type-check the operands each time it evaluates something so long as you're operating on the array as a whole (e.g. numpy_array * 2), but obviously the code below is not taking advantage of that. Is there a way to replace the internal loop with some kind of window function which could result in a speedup, or any other way using numpy/scipy to speed this up substantially in native python? Alternatively, is there a better way to do this in general (e.g. will it be much faster to write this loop in C++ and use weave)? ARRAY_LENGTH = 500000 INTERVAL_LENGTH = 15 close = np.array( xrange(ARRAY_LENGTH) ) volume = np.array( xrange(ARRAY_LENGTH) ) close, volume = close.astype('float64'), volume.astype('float64') results = [] for i in xrange(len(close) - INTERVAL_LENGTH): for j in xrange(i+1, i+INTERVAL_LENGTH): ret = close[j] / close[i] vol = sum( volume[i+1:j+1] ) if ret > 1.0001 and ret < 1.5 and vol > 100: results.append( [i, j, ret, vol] ) print results

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• What do you mean by the expressiveness in programming lanuguage?

  - by prosseek

  I see a lot of the word 'expressiveness' when people want to stress one language is better than the other. But I don't see exactly what they mean by it. Is it the verboseness/succinctness? I mean, if one language can write down something shorter than the other, does that mean expressiveness? Please refer to my other question - http://stackoverflow.com/questions/2411772/article-about-code-density-as-a-measure-of-programming-language-power Is it the power of the language? Paul Graham says that one language is more powerful than the other language in a sense that one language can do that the other language can't do (for example, LISP can do something with macro that the other language can't do). Is it just something that makes life easier? Regular expression can be one of the examples. Is it a different way of solving the same problem: something like SQL to solve the search problem? What do you think about the expressiveness of a programming lanuage? Can you show the expressiveness using some code? What's the relationship with the expressiveness and DSL? Do people come up with DSL to get the expressiveness?

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• Producing a static HTML site from XML content

  - by Skilldrick

  I have a long document in XML from which I need to produce static HTML pages (for distribution via CD). I know (to varying degrees) JavaScript, PHP and Python. The current options I've considered are listed here: I'm not ruling out JavaScript, so one option would be to use ajax to dynamically load the XML content into HTML pages. Learn some basic XSLT and produce HTML to the correct spec this way. Produce the site with PHP (for example) and then generate a static site. Write a script (in Python for example) to convert the XML into HTML. This is similar to the XSLT option but without having to learn XSLT. Useful information: The XML will likely change at some point, so I'd like to be able to easily regenerate the site. I'll have to produce some kind of menu for jumping around the document (so I'll need to produce some kind of index of the content). I'd like to know if anyone has any better ideas that I haven't thought of. If not, I'd like you to tell me which of my options seems the most sensible. I think I know what I'm going to do, but I'd like a second opinion. Thanks.

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