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  • SQL Server Management Studio Color Schemes?

    - by sunpech
    Is there a way to apply color schemes and themes to SQL Server Management Studio? I really enjoy the ones for Visual Studio 2005/2008/2010 and would love to have something like that. Color Schemes for Visual Studio: Create and share Visual Studio color schemes

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  • Get image pixels of prescribed color

    - by ohadsc
    Hi, I have an image (PNG or JPG) inside which there is at least one pixel of a certain RGB color I know in advance I want to find the pixel(s) of that color For example, I may have image.jpg inside which I know some pixel has the RGB value 255,100,200. I want a program that will give me the list of pixels (if any) of that color in the image Anyone know of a tool to help me with that ? Thanks !

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  • Selecting a Color Selector

    - by RCIX
    I'm looking for a nice full featured color selector program, i currently use Color Cop but i feel its missing some features (mainly a nice interface for selecting a color from a spectrum). Does anyone have any other suggestions?

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  • What is the best color combination for readability, easy of use, and reduced eye strain?

    - by Nick Berardi
    I am trying to pick out the optimal set of colors for a new website project. I want to do a traditional black on white look and feel for the main content. However my partner on the project wants to do a color combination that more looks like the traditional Windows Forms look and feel. Is there any research available on the best color combination's to use for readability, ease of use, and reduced eye strain?

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  • http request to cgi python script successful, but the script doesn't seem to run

    - by chipChocolate.py
    I have configured cgi scripts for my apache2 web server. Here is what I want to do: Client uploads the image to the server. (this already works) On success, I want to execute the python script to resize the image. I tried the following and the success function does execute but my python script does not seem to execute: Javascript code that sends the request: var input = document.getElementById('imageLoader'); imageName = input.value; var file = input.files[0]; if(file != undefined){ formData= new FormData(); console.log(formData.length); if(!!file.type.match(/image.*/)){ formData.append("image", file); $.ajax({ url: "upload.php", type: "POST", processData: false, contentType: false, success: function() { var input = document.getElementById('imageLoader'); imageName = input.value; var file = input.files[0]; formData = new FormData(); formData.append("filename", file); $.ajax({ url: "http://localhost/Main/cgi-bin/resize.py", type: "POST", data: formData, processData: false, contentType: false, success: function(data) { console.log(data); } }); // code continues... resize.py: #!/usr/bin/python import cgi import cgitb import Image cgitb.enable() data = cgi.FieldStorage() filename = data.getvalue("filename") im = Image.open("../JS/upload/" + filename) (width, height) = im.size maxWidth = 600 maxHeight = 400 if width > maxWidth: d = float(width) / maxWidth height = int(height / d) width = maxWidth if height > maxHeight: d = float(height) / maxHeight width = int(width / d) height = maxHeight size = (width, height) im = im.resize(size, Image.ANTIALIAS) im.save("../JS/upload/" + filename, quality=100) This is the apache2.conf: <Directory /var/www/html/Main/cgi-bin> AllowOverride None Options +ExecCGI SetHandler cgi-script AddHandler cgi-script .py .cgi Order allow,deny Allow from all </Directory> cgi-bin and python script file permissions: drwxrwxr-x 2 mou mou 4096 Aug 24 03:28 cgi-bin -rwxrwxrwx 1 mou mou 1673 Aug 24 03:28 resize.py Edit: Executing this code $.ajax({ url: "http://localhost/Main/cgi-bin/resize.py", type: "POST", data: formData, // formData = {"filename" : "the filename which was saved in a variable whie the image was uploaded"} processData: false, contentType: false, success: function(data) { alert(data); } }); it alerts the following: <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> <body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> --> </font> </font> </font> </script> </object> </blockquote> </pre> </table> </table> </table> </table> </table> </font> </font> </font><body bgcolor="#f0f0f8"> <table width="100%" cellspacing=0 cellpadding=2 border=0 summary="heading"> <tr bgcolor="#6622aa"> <td valign=bottom>&nbsp;<br> <font color="#ffffff" face="helvetica, arial">&nbsp;<br><big><big><strong>&lt;type 'exceptions.TypeError'&gt;</strong></big></big></font></td ><td align=right valign=bottom ><font color="#ffffff" face="helvetica, arial">Python 2.7.6: /usr/bin/python<br>Sun Aug 24 17:24:15 2014</font></td></tr></table> <p>A problem occurred in a Python script. Here is the sequence of function calls leading up to the error, in the order they occurred.</p> <table width="100%" cellspacing=0 cellpadding=0 border=0> <tr><td bgcolor="#d8bbff"><big>&nbsp;</big><a href="file:///var/www/html/Main/cgi-bin/resize.py">/var/www/html/Main/cgi-bin/resize.py</a> in <strong><module></strong>()</td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;&nbsp;&nbsp;10</small>&nbsp;<br> </tt></font></td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;&nbsp;&nbsp;11</small>&nbsp;filename&nbsp;=&nbsp;data.getvalue("filename")<br> </tt></font></td></tr> <tr><td bgcolor="#ffccee"><tt>=&gt;<small>&nbsp;&nbsp;&nbsp;12</small>&nbsp;im&nbsp;=&nbsp;Image.open("../JS/upload/"&nbsp;+&nbsp;filename)<br> </tt></td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;&nbsp;&nbsp;13</small>&nbsp;<br> </tt></font></td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;&nbsp;&nbsp;14</small>&nbsp;(width,&nbsp;height)&nbsp;=&nbsp;im.size<br> </tt></font></td></tr> <tr><td><small><font color="#909090">im <em>undefined</em>, <strong>Image</strong>&nbsp;= &lt;module 'Image' from '/usr/lib/python2.7/dist-packages/PILcompat/Image.pyc'&gt;, Image.<strong>open</strong>&nbsp;= &lt;function open&gt;, <strong>filename</strong>&nbsp;= '<font color="#c040c0">\xff\xd8\xff\xe0\x00\x10</font>JFIF<font color="#c040c0">\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xdb\x00</font>C<font color="#c040c0">\x00\x06\x04\x05\x06\x05\x04\x06\x06\x05\x06\x07\x07\x06\x08\n\x10\n\n\t\t\n\x14\x0e</font>...<font color="#c040c0">\x94\r\x17\x11</font>b<font color="#c040c0">\xcd\xdc\x1a\xfe\xf1\x05\x1b\x15\xd1</font>R<font color="#c040c0">\xce\xe9</font>*<font color="#c040c0">\xb5\x8e</font>b<font color="#c040c0">\x97\x82\x87</font>R<font color="#c040c0">\xf4\xaa</font>K<font color="#c040c0">\x83</font>6<font color="#c040c0">\xbf\xfb</font>0<font color="#c040c0">\xa0\xb6</font>8<font color="#c040c0">\xa9</font>C<font color="#c040c0">\x86\x8d\x96</font>n+E<font color="#c040c0">\xd3\x7f\x99\xff\xd9</font>'</font></small></td></tr></table> <table width="100%" cellspacing=0 cellpadding=0 border=0> <tr><td bgcolor="#d8bbff"><big>&nbsp;</big><a href="file:///usr/lib/python2.7/dist-packages/PIL/Image.py">/usr/lib/python2.7/dist-packages/PIL/Image.py</a> in <strong>open</strong>(fp='../JS/upload/<font color="#c040c0">\xff\xd8\xff\xe0\x00\x10</font>JFIF<font color="#c040c0">\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xdb\x00</font>C<font color="#c040c0">\x00\x06\x04\x05\x06\x05\x04\x06\x06\x05\x06</font>...<font color="#c040c0">\x94\r\x17\x11</font>b<font color="#c040c0">\xcd\xdc\x1a\xfe\xf1\x05\x1b\x15\xd1</font>R<font color="#c040c0">\xce\xe9</font>*<font color="#c040c0">\xb5\x8e</font>b<font color="#c040c0">\x97\x82\x87</font>R<font color="#c040c0">\xf4\xaa</font>K<font color="#c040c0">\x83</font>6<font color="#c040c0">\xbf\xfb</font>0<font color="#c040c0">\xa0\xb6</font>8<font color="#c040c0">\xa9</font>C<font color="#c040c0">\x86\x8d\x96</font>n+E<font color="#c040c0">\xd3\x7f\x99\xff\xd9</font>', mode='r')</td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;1994</small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;isPath(fp):<br> </tt></font></td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;1995</small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filename&nbsp;=&nbsp;fp<br> </tt></font></td></tr> <tr><td bgcolor="#ffccee"><tt>=&gt;<small>&nbsp;1996</small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;fp&nbsp;=&nbsp;builtins.open(fp,&nbsp;"rb")<br> </tt></td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;1997</small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else:<br> </tt></font></td></tr> <tr><td><font color="#909090"><tt>&nbsp;&nbsp;<small>&nbsp;1998</small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filename&nbsp;=&nbsp;""<br> </tt></font></td></tr> <tr><td><small><font color="#909090"><strong>fp</strong>&nbsp;= '../JS/upload/<font color="#c040c0">\xff\xd8\xff\xe0\x00\x10</font>JFIF<font color="#c040c0">\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00\xff\xdb\x00</font>C<font color="#c040c0">\x00\x06\x04\x05\x06\x05\x04\x06\x06\x05\x06</font>...<font color="#c040c0">\x94\r\x17\x11</font>b<font color="#c040c0">\xcd\xdc\x1a\xfe\xf1\x05\x1b\x15\xd1</font>R<font color="#c040c0">\xce\xe9</font>*<font color="#c040c0">\xb5\x8e</font>b<font color="#c040c0">\x97\x82\x87</font>R<font color="#c040c0">\xf4\xaa</font>K<font color="#c040c0">\x83</font>6<font color="#c040c0">\xbf\xfb</font>0<font color="#c040c0">\xa0\xb6</font>8<font color="#c040c0">\xa9</font>C<font color="#c040c0">\x86\x8d\x96</font>n+E<font color="#c040c0">\xd3\x7f\x99\xff\xd9</font>', <em>global</em> <strong>builtins</strong>&nbsp;= &lt;module '__builtin__' (built-in)&gt;, builtins.<strong>open</strong>&nbsp;= &lt;built-in function open&gt;</font></small></td></tr></table><p><strong>&lt;type 'exceptions.TypeError'&gt;</strong>: file() argument 1 must be encoded string without NULL bytes, not str <br><tt><small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</small>&nbsp;</tt>args&nbsp;= ('file() argument 1 must be encoded string without NULL bytes, not str',) <br><tt><small>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</small>&nbsp;</tt>message&nbsp;= 'file() argument 1 must be encoded string without NULL bytes, not str' <!-- The above is a description of an error in a Python program, formatted for a Web browser because the 'cgitb' module was enabled. In case you are not reading this in a Web browser, here is the original traceback: Traceback (most recent call last): File "/var/www/html/Main/cgi-bin/resize.py", line 12, in &lt;module&gt; im = Image.open("../JS/upload/" + filename) File "/usr/lib/python2.7/dist-packages/PIL/Image.py", line 1996, in open fp = builtins.open(fp, "rb") TypeError: file() argument 1 must be encoded string without NULL bytes, not str --> Does this mean that the formData I am sending over is empty?

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  • Using TypeScript in ASP.NET MVC Projects

    - by shiju
    In the previous blog post Microsoft TypeScript : A Typed Superset of JavaScript, I have given a brief introduction on TypeScript. In this post, I will demonstrate how to use TypeScript with ASP.NET MVC projects and how we can compile TypeScript within the ASP.NET MVC projects. Using TypeScript with ASP.NET MVC 3 Projects The Visual Studio plug-in for TypeScript provides an ASP.NET MVC 3 project template for TypeScript that lets you to compile TypeScript from the Visual Studio. The following screen shot shows the TypeScript template for ASP.NET MVC 3 project The “TypeScript Internet Application” template is just a ASP.NET MVC 3 internet application project template which will allows to compile TypeScript programs to JavaScript when you are building your ASP.NET MVC projects. This project template will have the following section in the .csproject file <None Include="Scripts\jquery.d.ts" /> <TypeScriptCompile Include="Scripts\site.ts" /> <Content Include="Scripts\site.js"> <DependentUpon>site.ts</DependentUpon> </Content> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } <Target Name="BeforeBuild"> <Exec Command="&amp;quot;$(PROGRAMFILES)\ Microsoft SDKs\TypeScript\0.8.0.0\tsc&amp;quot; @(TypeScriptCompile ->'&quot;%(fullpath)&quot;', ' ')" /> </Target> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The “BeforeBuild” target will allows you to compile TypeScript programs when you are building your ASP.NET MVC projects. The TypeScript project template will provide a typing reference file for the jQuery library named “jquery.d.ts”. The following default app.ts file referenced to jquery.d.ts 1: ///<reference path='jquery.d.ts' /> 2:   3: $(document).ready(function () { 4:   5: $(".btn-slide").click(function () { 6: $("#main").slideToggle("slow"); 7: $(this).toggleClass("active"); 8: }); 9:   10: }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Using TypeScript with ASP.NET MVC 4 Projects The current preview version of TypeScript is not providing a project template for ASP.NET MVC 4 projects. But you can use TypeScript with ASP.NET MVC 4 projects by editing the project’s .csproject file. You can take the necessary settings from ASP.NET MVC 3 project file. I have just added the following section in the end of the .csproj file of a ASP.NET MVC 4 project, which will allows to compile all TypeScript when building ASP.NET MVC 4 project. <ItemGroup> <TypeScriptCompile Include="$(ProjectDir)\**\*.ts" /> </ItemGroup> <Target Name="BeforeBuild"> <Exec Command="&amp;quot;$(PROGRAMFILES)\ Microsoft SDKs\TypeScript\0.8.0.0\tsc&amp;quot; @(TypeScriptCompile ->'&quot;%(fullpath)&quot;', ' ')" /> </Target> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }

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  • Mscorlib mocking minus the attribute

    - by mehfuzh
    Mocking .net framework members (a.k.a. mscorlib) is always a daunting task. It’s the breed of static and final methods and full of surprises. Technically intercepting mscorlib members is completely different from other class libraries. This is the reason it is dealt differently. Generally, I prefer writing a wrapper around an mscorlib member (Ex. File.Delete(“abc.txt”)) and expose it via interface but that is not always an easy task if you already have years old codebase. While mocking mscorlib members first thing that comes to people’s mind is DateTime.Now. If you Google through, you will find tons of example dealing with just that. May be it’s the most important class that we can’t ignore and I will create an example using JustMock Q2 with the same. In Q2 2012, we just get rid of the MockClassAtrribute for mocking mscorlib members. JustMock is already attribute free for mocking class libraries. We radically think that vendor specific attributes only makes your code smelly and therefore decided the same for mscorlib. Now, I want to fake DateTime.Now for the following class: public class NestedDateTime { public DateTime GetDateTime() { return DateTime.Now; } } It is the simplest one that can be. The first thing here is that I tell JustMock “hey we have a DateTime.Now in NestedDateTime class that we want to mock”. To do so, during the test initialization I write this: .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Mock.Replace(() => DateTime.Now).In<NestedDateTime>(x => x.GetDateTime());.csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } I can also define it for all the members in the class, but that’s just a waste of extra watts. Mock.Replace(() => DateTime.Now).In<NestedDateTime>(); Now question, why should I bother doing it? The answer is that I am not using attribute and with this approach, I can mock any framework members not just File, FileInfo or DateTime. Here to note that we already mock beyond the three but when nested around a complex class, JustMock was not intercepting it correctly. Therefore, we decided to get rid of the attribute altogether fixing the issue. Finally, I write my test as usual. [TestMethod] public void ShouldAssertMockingDateTimeFromNestedClass() { var expected = new DateTime(2000, 1, 1); Mock.Arrange(() => DateTime.Now).Returns(expected); Assert.Equal(new NestedDateTime().GetDateTime(), expected); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } That’s it, we are good. Now let me do the same for a random one, let’s say I want mock a member from DriveInfo: Mock.Replace<DriveInfo[]>(() => DriveInfo.GetDrives()).In<MsCorlibFixture>(x => x.ShouldReturnExpectedDriveWhenMocked()); Moving forward, I write my test: [TestMethod] public void ShouldReturnExpectedDriveWhenMocked() { Mock.Arrange(() => DriveInfo.GetDrives()).MustBeCalled(); DriveInfo.GetDrives(); Mock.Assert(()=> DriveInfo.GetDrives()); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here is one convention; you have to replace the mscorlib member before executing the target method that contains it. Here the call to DriveInfo is within the MsCorlibFixture therefore it should be defined during test initialization or before executing the test method. Hope this gives you the idea.

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  • Parenting Opengl with Groups in LibGDX

    - by Rudy_TM
    I am trying to make an object child of a Group, but this object has a draw method that calls opengl to draw in the screen. Its class its this public class OpenGLSquare extends Actor { private static final ImmediateModeRenderer renderer = new ImmediateModeRenderer10(); private static Matrix4 matrix = null; private static Vector2 temp = new Vector2(); public static void setMatrix4(Matrix4 mat) { matrix = mat; } @Override public void draw(SpriteBatch batch, float arg1) { // TODO Auto-generated method stub renderer.begin(matrix, GL10.GL_TRIANGLES); renderer.color(color.r, color.g, color.b, color.a); renderer.vertex(x0, y0, 0f); renderer.color(color.r, color.g, color.b, color.a); renderer.vertex(x0, y1, 0f); renderer.color(color.r, color.g, color.b, color.a); renderer.vertex(x1, y1, 0f); renderer.color(color.r, color.g, color.b, color.a); renderer.vertex(x1, y1, 0f); renderer.color(color.r, color.g, color.b, color.a); renderer.vertex(x1, y0, 0f); renderer.color(color.r, color.g, color.b, color.a); renderer.vertex(x0, y0, 0f); renderer.end(); } } In my screen class I have this, i call it in the constructor MyGroupClass spriteLab = new MyGroupClass(spriteSheetLab); OpenGLSquare square = new OpenGLSquare(); square.setX0(100); square.setY0(200); square.setX1(400); square.setY1(280); square.color.set(Color.BLUE); square.setSize(); //spriteLab.addActorAt(0, clock); spriteLab.addActor(square); stage.addActor(spriteLab); And the render in the screen I have @Override public void render(float arg0) { this.gl.glClear(GL10.GL_COLOR_BUFFER_BIT |GL10.GL_DEPTH_BUFFER_BIT); stage.draw(); stage.act(Gdx.graphics.getDeltaTime()); } The problem its that when i use opengl with parent, it resets all the other chldren to position 0,0 and the opengl renderer paints the square in the exact position of the screen and not relative to the parent. I tried using batch.enableBlending() and batch.disableBlending() that fixes the position problem of the other children, but not the relative position of the opengl drawing and it also puts alpha to the glDrawing. What am i doing wrong?:/

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  • Flex 3 color picker no color value

    - by kha.ya.ru
    I need "no color" value in flex 3/4 color picker component. Here are some options I've investigated: 1) External componet. Searched a lot but didn't managed to find a suitable one. There is a great color picker that meets my needs completely, but it is in action script 2 format. I need as3. 2) Enhance the existing built-in color picker component. So here I need your help. Do you have any ideas how the built-in color picker component can be enhanced in order to support "no color" value?

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  • Android - Convert Color Resource to Color in Domain Object

    - by Steve
    I have a domain object, where I created a method to return a text color based on the internal state of the domain object. I have defined the colors in a color.xml file as resources. The problem I have now, is that I would like to return a Color object instead of a resource ID from the domain object method. This way I can set the text color of a TextView by just calling textView.setTextColor(domainObj.getTextColor()) since it expects a Color object and not a resource ID. Currently, in an Activity, I can call getResources().getColor(domainObj.getTextColorResource()) to convert a resource ID to a color, but I would like this done in the domain object and I am not sure how I would do this when I do not have access to the getResources method. Are there any cleaner options than passing in a Resource object into the method, or domain object? Thanks

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  • How John Got 15x Improvement Without Really Trying

    - by rchrd
    The following article was published on a Sun Microsystems website a number of years ago by John Feo. It is still useful and worth preserving. So I'm republishing it here.  How I Got 15x Improvement Without Really Trying John Feo, Sun Microsystems Taking ten "personal" program codes used in scientific and engineering research, the author was able to get from 2 to 15 times performance improvement easily by applying some simple general optimization techniques. Introduction Scientific research based on computer simulation depends on the simulation for advancement. The research can advance only as fast as the computational codes can execute. The codes' efficiency determines both the rate and quality of results. In the same amount of time, a faster program can generate more results and can carry out a more detailed simulation of physical phenomena than a slower program. Highly optimized programs help science advance quickly and insure that monies supporting scientific research are used as effectively as possible. Scientific computer codes divide into three broad categories: ISV, community, and personal. ISV codes are large, mature production codes developed and sold commercially. The codes improve slowly over time both in methods and capabilities, and they are well tuned for most vendor platforms. Since the codes are mature and complex, there are few opportunities to improve their performance solely through code optimization. Improvements of 10% to 15% are typical. Examples of ISV codes are DYNA3D, Gaussian, and Nastran. Community codes are non-commercial production codes used by a particular research field. Generally, they are developed and distributed by a single academic or research institution with assistance from the community. Most users just run the codes, but some develop new methods and extensions that feed back into the general release. The codes are available on most vendor platforms. Since these codes are younger than ISV codes, there are more opportunities to optimize the source code. Improvements of 50% are not unusual. Examples of community codes are AMBER, CHARM, BLAST, and FASTA. Personal codes are those written by single users or small research groups for their own use. These codes are not distributed, but may be passed from professor-to-student or student-to-student over several years. They form the primordial ocean of applications from which community and ISV codes emerge. Government research grants pay for the development of most personal codes. This paper reports on the nature and performance of this class of codes. Over the last year, I have looked at over two dozen personal codes from more than a dozen research institutions. The codes cover a variety of scientific fields, including astronomy, atmospheric sciences, bioinformatics, biology, chemistry, geology, and physics. The sources range from a few hundred lines to more than ten thousand lines, and are written in Fortran, Fortran 90, C, and C++. For the most part, the codes are modular, documented, and written in a clear, straightforward manner. They do not use complex language features, advanced data structures, programming tricks, or libraries. I had little trouble understanding what the codes did or how data structures were used. Most came with a makefile. Surprisingly, only one of the applications is parallel. All developers have access to parallel machines, so availability is not an issue. Several tried to parallelize their applications, but stopped after encountering difficulties. Lack of education and a perception that parallelism is difficult prevented most from trying. I parallelized several of the codes using OpenMP, and did not judge any of the codes as difficult to parallelize. Even more surprising than the lack of parallelism is the inefficiency of the codes. I was able to get large improvements in performance in a matter of a few days applying simple optimization techniques. Table 1 lists ten representative codes [names and affiliation are omitted to preserve anonymity]. Improvements on one processor range from 2x to 15.5x with a simple average of 4.75x. I did not use sophisticated performance tools or drill deep into the program's execution character as one would do when tuning ISV or community codes. Using only a profiler and source line timers, I identified inefficient sections of code and improved their performance by inspection. The changes were at a high level. I am sure there is another factor of 2 or 3 in each code, and more if the codes are parallelized. The study’s results show that personal scientific codes are running many times slower than they should and that the problem is pervasive. Computational scientists are not sloppy programmers; however, few are trained in the art of computer programming or code optimization. I found that most have a working knowledge of some programming language and standard software engineering practices; but they do not know, or think about, how to make their programs run faster. They simply do not know the standard techniques used to make codes run faster. In fact, they do not even perceive that such techniques exist. The case studies described in this paper show that applying simple, well known techniques can significantly increase the performance of personal codes. It is important that the scientific community and the Government agencies that support scientific research find ways to better educate academic scientific programmers. The inefficiency of their codes is so bad that it is retarding both the quality and progress of scientific research. # cacheperformance redundantoperations loopstructures performanceimprovement 1 x x 15.5 2 x 2.8 3 x x 2.5 4 x 2.1 5 x x 2.0 6 x 5.0 7 x 5.8 8 x 6.3 9 2.2 10 x x 3.3 Table 1 — Area of improvement and performance gains of 10 codes The remainder of the paper is organized as follows: sections 2, 3, and 4 discuss the three most common sources of inefficiencies in the codes studied. These are cache performance, redundant operations, and loop structures. Each section includes several examples. The last section summaries the work and suggests a possible solution to the issues raised. Optimizing cache performance Commodity microprocessor systems use caches to increase memory bandwidth and reduce memory latencies. Typical latencies from processor to L1, L2, local, and remote memory are 3, 10, 50, and 200 cycles, respectively. Moreover, bandwidth falls off dramatically as memory distances increase. Programs that do not use cache effectively run many times slower than programs that do. When optimizing for cache, the biggest performance gains are achieved by accessing data in cache order and reusing data to amortize the overhead of cache misses. Secondary considerations are prefetching, associativity, and replacement; however, the understanding and analysis required to optimize for the latter are probably beyond the capabilities of the non-expert. Much can be gained simply by accessing data in the correct order and maximizing data reuse. 6 out of the 10 codes studied here benefited from such high level optimizations. Array Accesses The most important cache optimization is the most basic: accessing Fortran array elements in column order and C array elements in row order. Four of the ten codes—1, 2, 4, and 10—got it wrong. Compilers will restructure nested loops to optimize cache performance, but may not do so if the loop structure is too complex, or the loop body includes conditionals, complex addressing, or function calls. In code 1, the compiler failed to invert a key loop because of complex addressing do I = 0, 1010, delta_x IM = I - delta_x IP = I + delta_x do J = 5, 995, delta_x JM = J - delta_x JP = J + delta_x T1 = CA1(IP, J) + CA1(I, JP) T2 = CA1(IM, J) + CA1(I, JM) S1 = T1 + T2 - 4 * CA1(I, J) CA(I, J) = CA1(I, J) + D * S1 end do end do In code 2, the culprit is conditionals do I = 1, N do J = 1, N If (IFLAG(I,J) .EQ. 0) then T1 = Value(I, J-1) T2 = Value(I-1, J) T3 = Value(I, J) T4 = Value(I+1, J) T5 = Value(I, J+1) Value(I,J) = 0.25 * (T1 + T2 + T5 + T4) Delta = ABS(T3 - Value(I,J)) If (Delta .GT. MaxDelta) MaxDelta = Delta endif enddo enddo I fixed both programs by inverting the loops by hand. Code 10 has three-dimensional arrays and triply nested loops. The structure of the most computationally intensive loops is too complex to invert automatically or by hand. The only practical solution is to transpose the arrays so that the dimension accessed by the innermost loop is in cache order. The arrays can be transposed at construction or prior to entering a computationally intensive section of code. The former requires all array references to be modified, while the latter is cost effective only if the cost of the transpose is amortized over many accesses. I used the second approach to optimize code 10. Code 5 has four-dimensional arrays and loops are nested four deep. For all of the reasons cited above the compiler is not able to restructure three key loops. Assume C arrays and let the four dimensions of the arrays be i, j, k, and l. In the original code, the index structure of the three loops is L1: for i L2: for i L3: for i for l for l for j for k for j for k for j for k for l So only L3 accesses array elements in cache order. L1 is a very complex loop—much too complex to invert. I brought the loop into cache alignment by transposing the second and fourth dimensions of the arrays. Since the code uses a macro to compute all array indexes, I effected the transpose at construction and changed the macro appropriately. The dimensions of the new arrays are now: i, l, k, and j. L3 is a simple loop and easily inverted. L2 has a loop-carried scalar dependence in k. By promoting the scalar name that carries the dependence to an array, I was able to invert the third and fourth subloops aligning the loop with cache. Code 5 is by far the most difficult of the four codes to optimize for array accesses; but the knowledge required to fix the problems is no more than that required for the other codes. I would judge this code at the limits of, but not beyond, the capabilities of appropriately trained computational scientists. Array Strides When a cache miss occurs, a line (64 bytes) rather than just one word is loaded into the cache. If data is accessed stride 1, than the cost of the miss is amortized over 8 words. Any stride other than one reduces the cost savings. Two of the ten codes studied suffered from non-unit strides. The codes represent two important classes of "strided" codes. Code 1 employs a multi-grid algorithm to reduce time to convergence. The grids are every tenth, fifth, second, and unit element. Since time to convergence is inversely proportional to the distance between elements, coarse grids converge quickly providing good starting values for finer grids. The better starting values further reduce the time to convergence. The downside is that grids of every nth element, n > 1, introduce non-unit strides into the computation. In the original code, much of the savings of the multi-grid algorithm were lost due to this problem. I eliminated the problem by compressing (copying) coarse grids into continuous memory, and rewriting the computation as a function of the compressed grid. On convergence, I copied the final values of the compressed grid back to the original grid. The savings gained from unit stride access of the compressed grid more than paid for the cost of copying. Using compressed grids, the loop from code 1 included in the previous section becomes do j = 1, GZ do i = 1, GZ T1 = CA(i+0, j-1) + CA(i-1, j+0) T4 = CA1(i+1, j+0) + CA1(i+0, j+1) S1 = T1 + T4 - 4 * CA1(i+0, j+0) CA(i+0, j+0) = CA1(i+0, j+0) + DD * S1 enddo enddo where CA and CA1 are compressed arrays of size GZ. Code 7 traverses a list of objects selecting objects for later processing. The labels of the selected objects are stored in an array. The selection step has unit stride, but the processing steps have irregular stride. A fix is to save the parameters of the selected objects in temporary arrays as they are selected, and pass the temporary arrays to the processing functions. The fix is practical if the same parameters are used in selection as in processing, or if processing comprises a series of distinct steps which use overlapping subsets of the parameters. Both conditions are true for code 7, so I achieved significant improvement by copying parameters to temporary arrays during selection. Data reuse In the previous sections, we optimized for spatial locality. It is also important to optimize for temporal locality. Once read, a datum should be used as much as possible before it is forced from cache. Loop fusion and loop unrolling are two techniques that increase temporal locality. Unfortunately, both techniques increase register pressure—as loop bodies become larger, the number of registers required to hold temporary values grows. Once register spilling occurs, any gains evaporate quickly. For multiprocessors with small register sets or small caches, the sweet spot can be very small. In the ten codes presented here, I found no opportunities for loop fusion and only two opportunities for loop unrolling (codes 1 and 3). In code 1, unrolling the outer and inner loop one iteration increases the number of result values computed by the loop body from 1 to 4, do J = 1, GZ-2, 2 do I = 1, GZ-2, 2 T1 = CA1(i+0, j-1) + CA1(i-1, j+0) T2 = CA1(i+1, j-1) + CA1(i+0, j+0) T3 = CA1(i+0, j+0) + CA1(i-1, j+1) T4 = CA1(i+1, j+0) + CA1(i+0, j+1) T5 = CA1(i+2, j+0) + CA1(i+1, j+1) T6 = CA1(i+1, j+1) + CA1(i+0, j+2) T7 = CA1(i+2, j+1) + CA1(i+1, j+2) S1 = T1 + T4 - 4 * CA1(i+0, j+0) S2 = T2 + T5 - 4 * CA1(i+1, j+0) S3 = T3 + T6 - 4 * CA1(i+0, j+1) S4 = T4 + T7 - 4 * CA1(i+1, j+1) CA(i+0, j+0) = CA1(i+0, j+0) + DD * S1 CA(i+1, j+0) = CA1(i+1, j+0) + DD * S2 CA(i+0, j+1) = CA1(i+0, j+1) + DD * S3 CA(i+1, j+1) = CA1(i+1, j+1) + DD * S4 enddo enddo The loop body executes 12 reads, whereas as the rolled loop shown in the previous section executes 20 reads to compute the same four values. In code 3, two loops are unrolled 8 times and one loop is unrolled 4 times. Here is the before for (k = 0; k < NK[u]; k++) { sum = 0.0; for (y = 0; y < NY; y++) { sum += W[y][u][k] * delta[y]; } backprop[i++]=sum; } and after code for (k = 0; k < KK - 8; k+=8) { sum0 = 0.0; sum1 = 0.0; sum2 = 0.0; sum3 = 0.0; sum4 = 0.0; sum5 = 0.0; sum6 = 0.0; sum7 = 0.0; for (y = 0; y < NY; y++) { sum0 += W[y][0][k+0] * delta[y]; sum1 += W[y][0][k+1] * delta[y]; sum2 += W[y][0][k+2] * delta[y]; sum3 += W[y][0][k+3] * delta[y]; sum4 += W[y][0][k+4] * delta[y]; sum5 += W[y][0][k+5] * delta[y]; sum6 += W[y][0][k+6] * delta[y]; sum7 += W[y][0][k+7] * delta[y]; } backprop[k+0] = sum0; backprop[k+1] = sum1; backprop[k+2] = sum2; backprop[k+3] = sum3; backprop[k+4] = sum4; backprop[k+5] = sum5; backprop[k+6] = sum6; backprop[k+7] = sum7; } for one of the loops unrolled 8 times. Optimizing for temporal locality is the most difficult optimization considered in this paper. The concepts are not difficult, but the sweet spot is small. Identifying where the program can benefit from loop unrolling or loop fusion is not trivial. Moreover, it takes some effort to get it right. Still, educating scientific programmers about temporal locality and teaching them how to optimize for it will pay dividends. Reducing instruction count Execution time is a function of instruction count. Reduce the count and you usually reduce the time. The best solution is to use a more efficient algorithm; that is, an algorithm whose order of complexity is smaller, that converges quicker, or is more accurate. Optimizing source code without changing the algorithm yields smaller, but still significant, gains. This paper considers only the latter because the intent is to study how much better codes can run if written by programmers schooled in basic code optimization techniques. The ten codes studied benefited from three types of "instruction reducing" optimizations. The two most prevalent were hoisting invariant memory and data operations out of inner loops. The third was eliminating unnecessary data copying. The nature of these inefficiencies is language dependent. Memory operations The semantics of C make it difficult for the compiler to determine all the invariant memory operations in a loop. The problem is particularly acute for loops in functions since the compiler may not know the values of the function's parameters at every call site when compiling the function. Most compilers support pragmas to help resolve ambiguities; however, these pragmas are not comprehensive and there is no standard syntax. To guarantee that invariant memory operations are not executed repetitively, the user has little choice but to hoist the operations by hand. The problem is not as severe in Fortran programs because in the absence of equivalence statements, it is a violation of the language's semantics for two names to share memory. Codes 3 and 5 are C programs. In both cases, the compiler did not hoist all invariant memory operations from inner loops. Consider the following loop from code 3 for (y = 0; y < NY; y++) { i = 0; for (u = 0; u < NU; u++) { for (k = 0; k < NK[u]; k++) { dW[y][u][k] += delta[y] * I1[i++]; } } } Since dW[y][u] can point to the same memory space as delta for one or more values of y and u, assignment to dW[y][u][k] may change the value of delta[y]. In reality, dW and delta do not overlap in memory, so I rewrote the loop as for (y = 0; y < NY; y++) { i = 0; Dy = delta[y]; for (u = 0; u < NU; u++) { for (k = 0; k < NK[u]; k++) { dW[y][u][k] += Dy * I1[i++]; } } } Failure to hoist invariant memory operations may be due to complex address calculations. If the compiler can not determine that the address calculation is invariant, then it can hoist neither the calculation nor the associated memory operations. As noted above, code 5 uses a macro to address four-dimensional arrays #define MAT4D(a,q,i,j,k) (double *)((a)->data + (q)*(a)->strides[0] + (i)*(a)->strides[3] + (j)*(a)->strides[2] + (k)*(a)->strides[1]) The macro is too complex for the compiler to understand and so, it does not identify any subexpressions as loop invariant. The simplest way to eliminate the address calculation from the innermost loop (over i) is to define a0 = MAT4D(a,q,0,j,k) before the loop and then replace all instances of *MAT4D(a,q,i,j,k) in the loop with a0[i] A similar problem appears in code 6, a Fortran program. The key loop in this program is do n1 = 1, nh nx1 = (n1 - 1) / nz + 1 nz1 = n1 - nz * (nx1 - 1) do n2 = 1, nh nx2 = (n2 - 1) / nz + 1 nz2 = n2 - nz * (nx2 - 1) ndx = nx2 - nx1 ndy = nz2 - nz1 gxx = grn(1,ndx,ndy) gyy = grn(2,ndx,ndy) gxy = grn(3,ndx,ndy) balance(n1,1) = balance(n1,1) + (force(n2,1) * gxx + force(n2,2) * gxy) * h1 balance(n1,2) = balance(n1,2) + (force(n2,1) * gxy + force(n2,2) * gyy)*h1 end do end do The programmer has written this loop well—there are no loop invariant operations with respect to n1 and n2. However, the loop resides within an iterative loop over time and the index calculations are independent with respect to time. Trading space for time, I precomputed the index values prior to the entering the time loop and stored the values in two arrays. I then replaced the index calculations with reads of the arrays. Data operations Ways to reduce data operations can appear in many forms. Implementing a more efficient algorithm produces the biggest gains. The closest I came to an algorithm change was in code 4. This code computes the inner product of K-vectors A(i) and B(j), 0 = i < N, 0 = j < M, for most values of i and j. Since the program computes most of the NM possible inner products, it is more efficient to compute all the inner products in one triply-nested loop rather than one at a time when needed. The savings accrue from reading A(i) once for all B(j) vectors and from loop unrolling. for (i = 0; i < N; i+=8) { for (j = 0; j < M; j++) { sum0 = 0.0; sum1 = 0.0; sum2 = 0.0; sum3 = 0.0; sum4 = 0.0; sum5 = 0.0; sum6 = 0.0; sum7 = 0.0; for (k = 0; k < K; k++) { sum0 += A[i+0][k] * B[j][k]; sum1 += A[i+1][k] * B[j][k]; sum2 += A[i+2][k] * B[j][k]; sum3 += A[i+3][k] * B[j][k]; sum4 += A[i+4][k] * B[j][k]; sum5 += A[i+5][k] * B[j][k]; sum6 += A[i+6][k] * B[j][k]; sum7 += A[i+7][k] * B[j][k]; } C[i+0][j] = sum0; C[i+1][j] = sum1; C[i+2][j] = sum2; C[i+3][j] = sum3; C[i+4][j] = sum4; C[i+5][j] = sum5; C[i+6][j] = sum6; C[i+7][j] = sum7; }} This change requires knowledge of a typical run; i.e., that most inner products are computed. The reasons for the change, however, derive from basic optimization concepts. It is the type of change easily made at development time by a knowledgeable programmer. In code 5, we have the data version of the index optimization in code 6. Here a very expensive computation is a function of the loop indices and so cannot be hoisted out of the loop; however, the computation is invariant with respect to an outer iterative loop over time. We can compute its value for each iteration of the computation loop prior to entering the time loop and save the values in an array. The increase in memory required to store the values is small in comparison to the large savings in time. The main loop in Code 8 is doubly nested. The inner loop includes a series of guarded computations; some are a function of the inner loop index but not the outer loop index while others are a function of the outer loop index but not the inner loop index for (j = 0; j < N; j++) { for (i = 0; i < M; i++) { r = i * hrmax; R = A[j]; temp = (PRM[3] == 0.0) ? 1.0 : pow(r, PRM[3]); high = temp * kcoeff * B[j] * PRM[2] * PRM[4]; low = high * PRM[6] * PRM[6] / (1.0 + pow(PRM[4] * PRM[6], 2.0)); kap = (R > PRM[6]) ? high * R * R / (1.0 + pow(PRM[4]*r, 2.0) : low * pow(R/PRM[6], PRM[5]); < rest of loop omitted > }} Note that the value of temp is invariant to j. Thus, we can hoist the computation for temp out of the loop and save its values in an array. for (i = 0; i < M; i++) { r = i * hrmax; TEMP[i] = pow(r, PRM[3]); } [N.B. – the case for PRM[3] = 0 is omitted and will be reintroduced later.] We now hoist out of the inner loop the computations invariant to i. Since the conditional guarding the value of kap is invariant to i, it behooves us to hoist the computation out of the inner loop, thereby executing the guard once rather than M times. The final version of the code is for (j = 0; j < N; j++) { R = rig[j] / 1000.; tmp1 = kcoeff * par[2] * beta[j] * par[4]; tmp2 = 1.0 + (par[4] * par[4] * par[6] * par[6]); tmp3 = 1.0 + (par[4] * par[4] * R * R); tmp4 = par[6] * par[6] / tmp2; tmp5 = R * R / tmp3; tmp6 = pow(R / par[6], par[5]); if ((par[3] == 0.0) && (R > par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * tmp5; } else if ((par[3] == 0.0) && (R <= par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * tmp4 * tmp6; } else if ((par[3] != 0.0) && (R > par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * TEMP[i] * tmp5; } else if ((par[3] != 0.0) && (R <= par[6])) { for (i = 1; i <= imax1; i++) KAP[i] = tmp1 * TEMP[i] * tmp4 * tmp6; } for (i = 0; i < M; i++) { kap = KAP[i]; r = i * hrmax; < rest of loop omitted > } } Maybe not the prettiest piece of code, but certainly much more efficient than the original loop, Copy operations Several programs unnecessarily copy data from one data structure to another. This problem occurs in both Fortran and C programs, although it manifests itself differently in the two languages. Code 1 declares two arrays—one for old values and one for new values. At the end of each iteration, the array of new values is copied to the array of old values to reset the data structures for the next iteration. This problem occurs in Fortran programs not included in this study and in both Fortran 77 and Fortran 90 code. Introducing pointers to the arrays and swapping pointer values is an obvious way to eliminate the copying; but pointers is not a feature that many Fortran programmers know well or are comfortable using. An easy solution not involving pointers is to extend the dimension of the value array by 1 and use the last dimension to differentiate between arrays at different times. For example, if the data space is N x N, declare the array (N, N, 2). Then store the problem’s initial values in (_, _, 2) and define the scalar names new = 2 and old = 1. At the start of each iteration, swap old and new to reset the arrays. The old–new copy problem did not appear in any C program. In programs that had new and old values, the code swapped pointers to reset data structures. Where unnecessary coping did occur is in structure assignment and parameter passing. Structures in C are handled much like scalars. Assignment causes the data space of the right-hand name to be copied to the data space of the left-hand name. Similarly, when a structure is passed to a function, the data space of the actual parameter is copied to the data space of the formal parameter. If the structure is large and the assignment or function call is in an inner loop, then copying costs can grow quite large. While none of the ten programs considered here manifested this problem, it did occur in programs not included in the study. A simple fix is always to refer to structures via pointers. Optimizing loop structures Since scientific programs spend almost all their time in loops, efficient loops are the key to good performance. Conditionals, function calls, little instruction level parallelism, and large numbers of temporary values make it difficult for the compiler to generate tightly packed, highly efficient code. Conditionals and function calls introduce jumps that disrupt code flow. Users should eliminate or isolate conditionls to their own loops as much as possible. Often logical expressions can be substituted for if-then-else statements. For example, code 2 includes the following snippet MaxDelta = 0.0 do J = 1, N do I = 1, M < code omitted > Delta = abs(OldValue ? NewValue) if (Delta > MaxDelta) MaxDelta = Delta enddo enddo if (MaxDelta .gt. 0.001) goto 200 Since the only use of MaxDelta is to control the jump to 200 and all that matters is whether or not it is greater than 0.001, I made MaxDelta a boolean and rewrote the snippet as MaxDelta = .false. do J = 1, N do I = 1, M < code omitted > Delta = abs(OldValue ? NewValue) MaxDelta = MaxDelta .or. (Delta .gt. 0.001) enddo enddo if (MaxDelta) goto 200 thereby, eliminating the conditional expression from the inner loop. A microprocessor can execute many instructions per instruction cycle. Typically, it can execute one or more memory, floating point, integer, and jump operations. To be executed simultaneously, the operations must be independent. Thick loops tend to have more instruction level parallelism than thin loops. Moreover, they reduce memory traffice by maximizing data reuse. Loop unrolling and loop fusion are two techniques to increase the size of loop bodies. Several of the codes studied benefitted from loop unrolling, but none benefitted from loop fusion. This observation is not too surpising since it is the general tendency of programmers to write thick loops. As loops become thicker, the number of temporary values grows, increasing register pressure. If registers spill, then memory traffic increases and code flow is disrupted. A thick loop with many temporary values may execute slower than an equivalent series of thin loops. The biggest gain will be achieved if the thick loop can be split into a series of independent loops eliminating the need to write and read temporary arrays. I found such an occasion in code 10 where I split the loop do i = 1, n do j = 1, m A24(j,i)= S24(j,i) * T24(j,i) + S25(j,i) * U25(j,i) B24(j,i)= S24(j,i) * T25(j,i) + S25(j,i) * U24(j,i) A25(j,i)= S24(j,i) * C24(j,i) + S25(j,i) * V24(j,i) B25(j,i)= S24(j,i) * U25(j,i) + S25(j,i) * V25(j,i) C24(j,i)= S26(j,i) * T26(j,i) + S27(j,i) * U26(j,i) D24(j,i)= S26(j,i) * T27(j,i) + S27(j,i) * V26(j,i) C25(j,i)= S27(j,i) * S28(j,i) + S26(j,i) * U28(j,i) D25(j,i)= S27(j,i) * T28(j,i) + S26(j,i) * V28(j,i) end do end do into two disjoint loops do i = 1, n do j = 1, m A24(j,i)= S24(j,i) * T24(j,i) + S25(j,i) * U25(j,i) B24(j,i)= S24(j,i) * T25(j,i) + S25(j,i) * U24(j,i) A25(j,i)= S24(j,i) * C24(j,i) + S25(j,i) * V24(j,i) B25(j,i)= S24(j,i) * U25(j,i) + S25(j,i) * V25(j,i) end do end do do i = 1, n do j = 1, m C24(j,i)= S26(j,i) * T26(j,i) + S27(j,i) * U26(j,i) D24(j,i)= S26(j,i) * T27(j,i) + S27(j,i) * V26(j,i) C25(j,i)= S27(j,i) * S28(j,i) + S26(j,i) * U28(j,i) D25(j,i)= S27(j,i) * T28(j,i) + S26(j,i) * V28(j,i) end do end do Conclusions Over the course of the last year, I have had the opportunity to work with over two dozen academic scientific programmers at leading research universities. Their research interests span a broad range of scientific fields. Except for two programs that relied almost exclusively on library routines (matrix multiply and fast Fourier transform), I was able to improve significantly the single processor performance of all codes. Improvements range from 2x to 15.5x with a simple average of 4.75x. Changes to the source code were at a very high level. I did not use sophisticated techniques or programming tools to discover inefficiencies or effect the changes. Only one code was parallel despite the availability of parallel systems to all developers. Clearly, we have a problem—personal scientific research codes are highly inefficient and not running parallel. The developers are unaware of simple optimization techniques to make programs run faster. They lack education in the art of code optimization and parallel programming. I do not believe we can fix the problem by publishing additional books or training manuals. To date, the developers in questions have not studied the books or manual available, and are unlikely to do so in the future. Short courses are a possible solution, but I believe they are too concentrated to be much use. The general concepts can be taught in a three or four day course, but that is not enough time for students to practice what they learn and acquire the experience to apply and extend the concepts to their codes. Practice is the key to becoming proficient at optimization. I recommend that graduate students be required to take a semester length course in optimization and parallel programming. We would never give someone access to state-of-the-art scientific equipment costing hundreds of thousands of dollars without first requiring them to demonstrate that they know how to use the equipment. Yet the criterion for time on state-of-the-art supercomputers is at most an interesting project. Requestors are never asked to demonstrate that they know how to use the system, or can use the system effectively. A semester course would teach them the required skills. Government agencies that fund academic scientific research pay for most of the computer systems supporting scientific research as well as the development of most personal scientific codes. These agencies should require graduate schools to offer a course in optimization and parallel programming as a requirement for funding. About the Author John Feo received his Ph.D. in Computer Science from The University of Texas at Austin in 1986. After graduate school, Dr. Feo worked at Lawrence Livermore National Laboratory where he was the Group Leader of the Computer Research Group and principal investigator of the Sisal Language Project. In 1997, Dr. Feo joined Tera Computer Company where he was project manager for the MTA, and oversaw the programming and evaluation of the MTA at the San Diego Supercomputer Center. In 2000, Dr. Feo joined Sun Microsystems as an HPC application specialist. He works with university research groups to optimize and parallelize scientific codes. Dr. Feo has published over two dozen research articles in the areas of parallel parallel programming, parallel programming languages, and application performance.

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  • Apache + Passenger not passing on custom status codes

    - by harm
    I'm currently building an API. This API communicates with the client via status codes. I created several custom status codes (as per http://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html#sec6) in order to inform the client on certain things. For example I introduced the 481 status code to signify a specific client error. The Rails app I wrote works like a charm. But when Apache and Passenger are serving it things run aground. When I provoke a 481 error the response header looks like this: HTTP/1.1 500 Internal Server Error Date: Wed, 19 May 2010 06:37:05 GMT Server: Apache/2.2.9 (Debian) Phusion_Passenger/2.2.5 mod_ssl/2.2.9 OpenSSL/0.9.8g X-Powered-By: Phusion Passenger (mod_rails/mod_rack) 2.2.5 Cache-Control: no-cache X-Runtime: 1938 Set-Cookie: _session_id=32bc259dc763193ad57ae7dc19d5f57e; path=/; HttpOnly Content-Length: 62 Status: 481 Content-Type: application/json; charset=utf-8 As you can see the original Status header is still there almost a the end. But the 'true' status header (the very first line) is quiet different. It seems that Apache doesn't like Status headers it has no knowledge of and thus assumes an error. Is there anyway to fix this? Maybe via the mod_headers ( http://httpd.apache.org/docs/2.2/mod/mod_headers.html) module? I don't know enough of Apache to figure this out on my own. Thanks,

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  • Color Profiles in Windows 7 vs. XP

    - by flxkid
    I have a Brother Color Laser Printer and an HP 8150DN. I have a local Windows 7 Pro machine that I do graphics work on. I created a letterhead that when printed from my machine looks dark and rich on either the mono HP or the color Brother laser. I take this same letterhead, and move it onto our network for use by our users which are all on XP. Then they print the same file, it is washed out on either printer. I've confirmed that the printer settings we're using are identical. I've confirmed that its not related to the program or even specifically to the letterhead. I can duplicate this with other files too. I'm down to XP vs Windows 7 being the issue. I'm fairly certain now that color profiles are involved. I have no clue how to fix it though. Any suggestions would be much appreciated.

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  • Color Profiles in Windows 7 vs. XP

    - by flxkid
    I have a Brother Color Laser Printer and an HP 8150DN. I have a local Windows 7 Pro machine that I do graphics work on. I created a letterhead that when printed from my machine looks dark and rich on either the mono HP or the color Brother laser. I take this same letterhead, and move it onto our network for use by our users which are all on XP. Then they print the same file, it is washed out on either printer. I've confirmed that the printer settings we're using are identical. I've confirmed that its not related to the program or even specifically to the letterhead. I can duplicate this with other files too. I'm down to XP vs Windows 7 being the issue. I'm fairly certain now that color profiles are involved. I have no clue how to fix it though. Any suggestions would be much appreciated.

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  • Color Management, Linux, Photoshop C2 via Wine

    - by Kyle Brandt
    I am new to Color Management CMS, so doing it on Linux, and then throw Wine into the mix ... and I am a little lost. However, I have Photoshop CS2 running okay with Crossover Professional on Ubuntu 9.10. I have a Canon 450D (Rebel XSI) and I imagine I will be able to find a profile for my printer. I ordered a Huey Calibrator (yet to come). I guess I will run into problems with Nvidia Twinview, but one calibrated monitor is good enough for now. Am I going to be able to get color management from Camera -- Monitor -- Print? Most specifically, when I get the Monitor profile loaded with something like xcalib, will Photoshop CS2 run through wine (crossover Pro) understand that? Will I need to select specific things / profiles in photoshop under the edit::Color Settings menu? I found several pages on http://jcornuz.wordpress.com/ helpful, but am wondering about the Wine issue, and anything else anyone can do to help.

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  • Color Calibrate Dual Monitor XP SP2

    - by Laramie
    This topic has been touched on before but not really answered. I have a dual monitor system and the colors differ wildly. I currently live Buenos Aires where color correction hardware costs premium prices. I do some graphic design, but don't require a pro-level calibration. That said, I'd like my monitors to be set as close to "true color" as possible. I've located the useful and free Monitor Calibration Wizard, but it seems to adjust the entire system internally at startup. I could use the Microsoft Color Control Panel Applet to set a different ICC or ICM profile for each monitor, but the Monitor Calibration Wizard outputs its own format for profiles.

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  • Lost "VGA Display" color profile in OS X

    - by Justin Love
    OS X Display settings used to have a color profile named VGA Display, which I found quite usefully for finding color problems before hooking up a projector. Currently, this profile (along with a number of others I've collected from projectors in the past year) is not available. I'm currently OS X 10.6.6 and my best guess is the profiles got wiped out during the last upgrade. None of the available color profiles seem to stink quite enough. Am I overlooking a renamed profile? Is there somewhere I could get a 'VGA Display' profile to install on my computer?

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  • Color Calibrate Dual Monitor XP SP2

    - by Laramie
    This topic has been touched on before but not really answered. I have a dual monitor system and the colors differ wildly. I currently live Buenos Aires where color correction hardware costs premium prices. I do some graphic design, but don't require a pro-level calibration. That said, I'd like my monitors to be set as close to "true color" as possible. I've located the useful and free Monitor Calibration Wizard, but it seems to adjust the entire system internally at startup. I could use the Microsoft Color Control Panel Applet to set a different ICC or ICM profile for each monitor, but the Monitor Calibration Wizard outputs its own format for profiles.

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  • ActionScript black color value is NaN

    - by TheDarkIn1978
    i'm trying to determine if a color has been supplied as an optional argument to a function. in order to determine this, i'm simply writing if(color){...} and supplying NaN if i don't want there to be a color. however, it seems that the color black (0x000000) also equates to NaN. how can i determine if a supplied color number argument is present and black if 0x000000 is passed as the argument?

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  • List of phone number country codes

    - by jesperlind
    On this Wikipedia entry I found out that ITU Telecommunication Standardization Sector (ITU-T) is providing such list of country calling codes. Here is a pdf: http://www.itu.int/dms_pub/itu-t/opb/sp/T-SP-E.164D-2009-PDF-E.pdf I wonder where to find this in a xml file or similar? I need to do find out which country a phone number is from, both in javascript and c#.

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  • JLabel wont change color twice

    - by Aly
    Hi, I have the following code: public class Test extends JFrame implements ActionListener{ private static final Color TRANSP_WHITE = new Color(new Float(1), new Float(1), new Float(1), new Float(0.5)); private static final Color TRANSP_RED = new Color(new Float(1), new Float(0), new Float(0), new Float(0.1)); private static final Color[] COLORS = new Color[]{ TRANSP_RED, TRANSP_WHITE}; private int index = 0; private JLabel label; private JButton button; public Test(){ super(); setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS)); label = new JLabel("hello world"); label.setOpaque(true); label.setBackground(TRANSP_WHITE); getContentPane().add(label); button = new JButton("Click Me"); button.addActionListener(this); getContentPane().add(button); pack(); setVisible(true); } @Override public void actionPerformed(ActionEvent e) { if(e.getSource().equals(button)){ label.setBackground(COLORS[index % (COLORS.length - 1)]); } } public static void main(String[] args) { new Test(); } } When I run it I get the label with the TRANSP_WHITE background and then when I click the button this color changes to TRANSP_RED but when I click it again I see no change in color. Does anyone know why? Thanks

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