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  • SASS mixin for swapping images / floats on site language (change)

    - by DBUK
    Currently using SASS on a website build. It is my first project using it, tried a little LESS before and liked it. I made a few basic mixins and variables with LESS, super useful stuff! I am trying to get my head around SASS mixins, and syntax, specifically for swapping images when the page changes to a different language, be that with body ID changing or <html lang="en">. And, swapping floats around if, for example, a website changed to chinese. So a mixin where float left is float left unless language is AR and then it becomes float right. With LESS I think it would be something like: .headerBg() when (@lang = en) {background-image:url(../img/hello.png);} .headerBg() when (@lang = it) {background-image:url(../img/ciao.png);} .header {.headerBg(); width: 200px; height:100px} .floatleft() when (@lang = en) { float: left;} .floatleft() when (@lang = ar) { float: right;} .logo {.floatleft();} Its the syntax I am having problems with combined with a brain melting day.

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  • Structure map and generics (in XML config)

    - by James D
    Hi I'm using the latest StructureMap (2.5.4.264), and I need to define some instances in the xml configuration for StructureMap using generics. However I get the following 103 error: Unhandled Exception: StructureMap.Exceptions.StructureMapConfigurationException: StructureMap configuration failures: Error: 103 Source: Requested PluginType MyTest.ITest`1[[MyTest.Test,MyTest]] configured in Xml cannot be found Could not create a Type for 'MyTest.ITest`1[[MyTest.Test,MyTest]]' System.ApplicationException: Could not create a Type for 'MyTest.ITest`1[[MyTest.Test,MyTest]]' ---> System.TypeLoadException: Could not loa d type 'MyTest.ITest`1' from assembly 'StructureMap, Version=2.5.4.264, Culture=neutral, PublicKeyToken=e60ad81abae3c223'. at System.RuntimeTypeHandle._GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, Boolean loadTypeFromPartialName) at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) at System.RuntimeType.PrivateGetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& s tackMark) at System.Type.GetType(String typeName, Boolean throwOnError) at StructureMap.Graph.TypePath.FindType() --- End of inner exception stack trace --- at StructureMap.Graph.TypePath.FindType() at StructureMap.Configuration.GraphBuilder.ConfigureFamily(TypePath pluginTypePath, Action`1 action) A simply replication of the code is as follows: public interface ITest<T> { } public class Test { } public class Concrete : ITest<Test> { } Which I then wish to define in the XML configuration something as follows: <DefaultInstance PluginType="MyTest.ITest`1[[MyTest.Test,MyTest]],MyTest" PluggedType="MyTest.Concrete,MyTest" Scope="Singleton" /> I've been racking my brain, however I can't see what I'm doing wrong - I've used Type.GetType to verify the type actually is valid which it is. Anyone have any ideas? Thanks !

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  • Is it possible to pull a webpage or content from the web into a widget on the android home screen

    - by cdg
    Hi there. I have a php web page that will randomize an image that is 158x154. I was able to get the android application to work, but would also like to get it to work as a widget. How the heck can I get a widget to pull information from the net? I got the widget to work and layout correctly with a black sample image. I have tried to look at the wiki sample, but it is a bit too complicated for my little brain to grasp. The data that gets pulled looks something like: <html><body bgcolor="#000000">center> <a href="http://www.website.com" target="_blank"> <img border="0" src="http://www.webiste.com//0.gif"></a> <img src="http://www.webiste.com" style="border:none;" /> </center></body></html> Help please. I am pulling my hair out trying to figure this out.

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  • efficient sort with custom comparison, but no callback function

    - by rob
    I have a need for an efficient sort that doesn't have a callback, but is as customizable as using qsort(). What I want is for it to work like an iterator, where it continuously calls into the sort API in a loop until it is done, doing the comparison in the loop rather than off in a callback function. This way the custom comparison is local to the calling function (and therefore has access to local variables, is potentially more efficient, etc). I have implemented this for an inefficient selection sort, but need it to be efficient, so prefer a quick sort derivative. Has anyone done anything like this? I tried to do it for quick sort, but trying to turn the algorithm inside out hurt my brain too much. Below is how it might look in use. // the array of data we are sorting MyData array[5000], *firstP, *secondP; // (assume data is filled in) Sorter sorter; // initialize sorter int result = sortInit (&sorter, array, 5000, (void **)&firstP, (void **)&secondP, sizeof(MyData)); // loop until complete while (sortIteration (&sorter, result) == 0) { // here's where we do the custom comparison...here we // just sort by member "value" but we could do anything result = firstP->value - secondP->value; }

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  • Pre Project Documentation

    - by DeanMc
    I have an issue that I feel many programmers can relate to... I have worked on many small scale projects. After my initial paper brain storm I tend to start coding. What I come up with is usually a rough working model of the actual application. I design in a disconnected fashion so I am talking about underlying code libraries, user interfaces are the last thing as the library usually dictates what is needed in the UI. As my projects get bigger I worry that so should my "spec" or design document. The above paragraph, from my investigations, is echoed all across the internet in one fashion or another. When a UI is concerned there is a bit more information but it is UI specific and does not relate to code libraries. What I am beginning to realise is that maybe code is code is code. It seems from my extensive research that there is no 1:1 mapping between a design document and the code. When I need to research a topic I dump information into OneNote and from there I prioritise features into versions and then into related chunks so that development runs in a fairly linear fashion, my tasks tend to look like so: Implement Binary File Reader Implement Binary File Writer Create Object to encapsulate Data for expression to the caller Now any programmer worth his salt is aware that between those three to do items could be a potential wall of code that could expand out to multiple files. I have tried to map the complete code process for each task but I simply don't think it can be done effectively. By the time one mangles pseudo code it is essentially code anyway so the time investment is negated. So my question is this: Am I right in assuming that the best documentation is the code itself. We are all in agreement that a high level overview is needed. How high should this be? Do you design to statement, class or concept level? What works for you?

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  • Looking for Simplified Overview of EJB3

    - by sdoca
    Hi I'm looking for a simplified overview of EJB3 components. I seem to understand most of the pieces of the puzzle, but can't quite get them to fit together in my brain as a full picture. I've developed numerous web applications (wars) that have been deployed on Tomcat before, but not a full-fledged EE application (ear). I would like the overview to be as generic as possible. I'm not looking for a tutorial on how to set up EJB3 on Glassfish built in NetBeans or some other vendor specific tutorial that's more about the IDE than the technology. I keep reading about Java, ejb-jar, web and ear modules but am not clear on what these different modules contain and how to use them to put together my app. In my case, I want to write a simple database CRUD web application. The first step is simple; create entity classes that model the database tables my app will be using. I plan on using annotations. Should I create a jar that contains just these enity classes? Is this the ejb-jar module (sometimes referred to as the Java module)? Next, I'll need some business logic classes that make use of the entity classes. These are the session beans (stateless or stateful) correct? Should these be packaged in the same jar as the entity classes or a separate jar? Finally, I'll need some sort of web interface (I'll be creating a JSF portlet) application that makes use of the both the session and entity beans. Together with the above jar(s), this will be my war? Assuming the above to be correct, what is involved in creating an ear? Forgive me if this post is vague, but I'm having a hard time defining what it is I don't understand. Thanks for any help!

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  • Reflection and Operator Overloads in C#

    - by TenshiNoK
    Here's the deal. I've got a program that will load a given assembly, parse through all Types and their Members and compile a TreeView (very similar to old MSDN site) and then build HTML pages for each node in the TreeView. It basically takes a given assembly and allows the user to create their own MSDN-like library for it for documentation purposes. Here's the problem I've run into: whenever an operator overload is encounted in a defined class, reflection returns that as a "MethodInfo" with the name set to something like "op_Assign" or "op_Equality". I want to be able to capture these and list them properly, but I can't find anything in the MethodInfo object that is returned to accurately identify that I'm looking at an operator. I definitely don't want to just capture everything that starts with "op_", since that will most certainly (at some point) will pick up a method it's not supposed to. I know that other methods and properties that are "special cases" like this one have the "IsSpecialName" property set, but appearantly that's not the case with operators. I've been scouring the 'net and wracking my brain to two days trying to figure this one out, so any help will be greatly appreciated.

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  • Can I get a reference to an object created in a jQuery plugin?

    - by gargantaun
    Perhaps my brain is fried, but I'm writing a plugin that created an tweaks an element, but also creates an object that i'd like access to. So the plugin looks like this (function ($) { $.fn.myPlugin = function () { return this.each(function () { // do some stuff to the element... this.objectInstance = new usefulObject(); }); }; })(jQuery); function usefulObject(){ // useful object properties and methods.... this.doSomething = function(){ alert("Don't google Google. You'll break the internet."); } } so when I call the plugin, I also want to be able to get access to that usefulObject that I created. I thought something like this might work.... tweakedElement = $("#someDiv").myPlugin(); tweakedElement.objectInstance.doSomething(); ... but that's not working. How can I achieve this? Can I achieve this? Answers on a postcard, or down below, whichever suits you.

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  • Set DetailsView as selected row of GridView

    - by Nix
    I am afraid this is a brain fart question. But I have searched around and have not been able to find the answer. I am creating a GridView/DetailsView page. I have a grid that displays a bunch of rows, when a row is selected it uses a DetailsView to allow for Insert/Update. My question is what is the best way to link these? I do not want to reach out to the web service again, all the data i need is in the selected grid view row. I basically have 2 separate data sources that share the same "DataObjectTypeName", the first data source retrieves the data, and the other to do the CRUD. What is the best way to transfer the Selected Grid View row to the Details View? Am I going to have to manualy handle the Insert/Update events and call the data source myself? <asp:GridView ID="gvDetails" runat="server" DataKeyNames="ID, Code" DataSourceID="odsSearchData" > <Columns> <asp:BoundField DataField="RowA" HeaderText="A" SortExpression="RowA" /> <asp:BoundField DataField="RowB" HeaderText="B" SortExpression="RowB" /> <asp:BoundField DataField="RowC" HeaderText="C" SortExpression="RowC" /> ....Code... <asp:DetailsView ID="dvDetails" runat="server" DataKeyNames="ID, Code" DataSourceID="odsCRUD" GridLines="None" DefaultMode="Edit" AutoGenerateRows="false" Visible="false" Width="100%"> <Fields> <asp:BoundField DataField="RowA" HeaderText="A" SortExpression="RowA" /> <asp:BoundField DataField="RowB" HeaderText="B" SortExpression="RowB" /> <asp:BoundField DataField="RowC" HeaderText="C" SortExpression="RowC" /> ...

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  • WPF app startup problems

    - by Dave
    My brain is all over the map trying to fully understand Unity right now. So I decided to just dive in and start adding it in a branch to see where it takes me. Surprisingly enough (or maybe not), I am stuck just getting my darn Application to load properly. It seems like the right way to do this is to override OnStartup in App.cs. I've removed my StartupUri from App.xaml so it doesn't create my GUI XAML. My App.cs now looks something like this: public partial class App : Application { private IUnityContainer container { get; set; } protected override void OnStartup(StartupEventArgs e) { container = new UnityContainer(); GUI gui = new GUI(); gui.Show(); } protected override void OnExit(ExitEventArgs e) { container.Dispose(); base.OnExit(e); } } The problem is that nothing happens when I start the app! I put a breakpoint at the container assignment, and it never gets hit. What am I missing? App.xaml is currently set to ApplicationDefinition, but I'd expect this to work because some sample Unity + WPF code I'm looking at (from Codeplex) does the exact same thing, except that it works! I've also started the app by single-stepping, and it eventually hits the first line in App.xaml. When I step into this line, that's when the app just starts "running", but I don't see anything (and my breakpoint isn't hit). If I do the exact same thing in the sample application, stepping into App.xaml puts me right into OnStartup, which is what I'd expect to happen. Argh! Is it a Bad Thing to just put the Unity construction in my GUI's Window_Loaded event handler? Does it really need to be at the App level?

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  • Javascipt Regular Expression

    - by Ghoul Fool
    Having problems with regular expressions in JavaScript. I've got a number of strings that need delimiting by commas. Unfortunately the sub strings don't have quotes around them which would make life easier. var str1 = "Three Blind Mice 13 Agents of Cheese Super 18" var str2 = "An Old Woman Who Lived in a Shoe 7 Pixies None 12" var str3 = "The Cow Jumped Over The Moon 21 Crazy Cow Tales Wonderful 9" They are in the form of PHRASE1 (Mixed type with spaces") INTEGER1 (1 or two digit) PHRASE2 (Mixed type with spaces") WORD1 (single word mixed type, no spaces) INTEGER2 (1 or two digit) so I should get: result1 = "Three Blind Mice, 13, Agents of Cheese, Super, 18" result2 = "An Old Woman Who Lived in a Shoe, 7, Pixies, None, 12" result3 = "A Cow Jumped Over The Moon, 21, Crazy Cow Tales, Wonderful, 9" I've looked at txt2re.com, but can't quite get what I need and ended up delimiting by hand. But I'm sure it can be done, albeit someone with a bigger brain. There are lots of examples of regEx but I couldn't find any to deal with phrases; so I was wondering if anyone could help me out. Thank you.

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  • When is a bool not a bool (compiler warning C4800)

    - by omatai
    Consider this being compiled in MS Visual Studio 2005 (and probably others): CPoint point1( 1, 2 ); CPoint point2( 3, 4 ); const bool point1And2Identical( point1 == point2 ); // C4800 warning const bool point1And2TheSame( ( point1 == point2 ) == TRUE ); // no warning What the...? Is the MSVC compiler brain-dead? As far as I can tell, TRUE is #defined as 1, without any type information. So by what magic is there any difference between these two lines? Surely the type of the expression inside the brackets is the same in both cases? [This part of the question now satisfactorily answered in the comments just below] Personally, I think that avoiding the warning by using the == TRUE option is ugly (though less ugly than the != 0 alternative, despite being more strictly correct), and it is better to use #pragma warning( disable:4800 ) to imply "my code is good, the compiler is an ass". Agree? Note - I have seen all manner of discussion on C4800 talking about assigning ints to bools, or casting a burger combo with large fries (hold the onions) to a bool, and wondering why there are strange results. I can't find a clear answer on what seems like a much simpler question... that might just shine line on C4800 in general.

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  • iphone: memory problems after refactor

    - by agilpwc
    I had a NIB with several view controllers in it. I modified the code and used Interface Builder decomose interface to get all the view controllers in their own Nib. But now with empty core data database, I'm getting "message sent to deallocated instance" errors. Here is the code flow: From the RootViewController this is called: if (self.dogController == nil) { DogViewController *controller = [[DogViewController alloc] initWithNibName:@"DogViewController" bundle:nil]; self.dogController = controller; [controller release]; } self.dogController.managedObjectContext = self.managedObjectContext; [self.navigationController pushViewController:self.dogController animated:YES]; Then in a dogController a button is pressed to insert a new object and the following code is excuted and the error hits on the save, according to the trace NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext]; NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity]; NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context]; // If appropriate, configure the new managed object. [newManagedObject setValue:[NSDate date] forKey:@"birthDate"]; [newManagedObject setValue:@"-" forKey:@"callName"]; // Save the context. NSError *error = nil; if (![context save:&error]) { Then the error produced in the console is * -[JudgeViewController numberOfSectionsInTableView:]: message sent to deallocated instance 0x598e580 I'm racking my brain for hours and I can't figure out where my minor changes made something messed up. Any ideas?

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  • What's the deal with the hidden Throw when catching a ThreadAbortException?

    - by priehl
    I'm going through a book of general c# development, and I've come to the thread abort section. The book says something along the lines that when you call Thread.Abort() on another thread, that thread will throw a ThreadAbortException, and even if you tried to supress it it would automatically rethrow it, unless you did some bs that's generally frowned upon. Here's the simple example offered. using System; using System.Threading; public class EntryPoint { private static void ThreadFunc() { ulong counter = 0; while (true) { try { Console.WriteLine("{0}", counter++); } catch (ThreadAbortException) { // Attempt to swallow the exception and continue. Console.WriteLine("Abort!"); } } } static void Main() { try { Thread newThread = new Thread(new ThreadStart(EntryPoint.ThreadFunc)); newThread.Start(); Thread.Sleep(2000); // Abort the thread. newThread.Abort(); // Wait for thread to finish. newThread.Join(); } catch (Exception e) { Console.WriteLine(e.ToString()); } } } The book says: When your thread finishes processing the abort exception, the runtime implicitly rethrows it at the end of your exception handler. It’s the same as if you had rethrown the exception yourself. Therefore, any outer exception handlers or finally blocks will still execute normally. In the example, the call to Join won’t be waiting forever as initially expected. So i wrapped a try catch around the Thread.Abort() call and set a break point, expecting it to hit this, considering the text says "any outer exception handlers or finally blocks will still execute normally". BUT IT DOES NOT. I'm racking my brain to figure out why. Anyone have any thoughts on why this isn't the case? Is the book wrong? Thanks in advance.

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  • What do you call a set of Javascript closures that share a common context?

    - by Ed Stauff
    I've been trying to learn closures (in Javascript), which kind of hurts my brain after way too many years with C# and C++. I think I now have a basic understanding, but one thing bothers me: I've visited lots of websites in this Quest for Knowledge, and nowhere have I seen a word (or even a simple two-word phrase) that means "a set of Javascript closures that share a common execution context". For example: function CreateThingy (name, initialValue) { var myName = name; var myValue = initialValue; var retObj = new Object; retObj.getName = function() { return myName; } retObj.getValue = function() { return myValue; } retObj.setValue = function(newValue) { myValue = newValue; } return retObj; }; From what I've read, this seems to be one common way of implementing data hiding. The value returned by CreateThingy is, of course, an object, but what would you call the set of functions which are properties of that object? Each one is a closure, but I'd like a name I can used to describe (and think about) all of them together as one conceptual entity, and I'd rather use a commonly accepted name than make one up. Thanks! -- Ed

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  • How to best manage multi-frame MovieClips with classes?

    - by Arms
    After switching to AS3, I've been having a hell of a time figuring out the best way to manage MovieClips that have UI elements spread across multiple frames with a single class. An example that I am working on now is a simple email form. I have a MovieClip with two frames: the 1st frame has the form elements (text inputs, submit button) the 2nd frame has a "thank you" message and a button to go back to the first frame (to send another email) In the library I have linked the MovieClip to a custom class (Emailer). My immediate problem is how do I assign a MouseEvent.CLICK event to the button on the 2nd frame? I should note at this point that I am trying to avoid putting code on the timeline (except for stop() calls). This is how I am 'solving' the problem now: Emailer registers an event listener for a frame change ( addEventListener("frame 2", onFrameChange) ) On the 2nd frame of the MovieClip I am calling dispatchEvent(new Event("frame 2")); (I would prefer to not have this code on the frame, but I don't know what else to do) My two complaints with this method are that, first I have calls to addEventListener spread out across different class methods (I would rather have all UI event listeners registered in one method), and second that I have to dispatch those custom "onFrameChange" events. The second complaint grows exponentially for MovieClips that have more than just 2 frames. My so called solution feels makes me feel dirty and makes my brain hurt. I am looking for any advice on what to do differently. Perhaps there's a design pattern I should be looking at? Should I swallow my pride and write timeline code even though the rest of my application is written in class files (and I abhor the Flash IDE code editor)? I absolutely LOVE the event system, and have no problem coding applications with it, but I feel like I'm stuck thinking in terms of AS2 when working with mutl-frame movieclips and code. Any and all help would be greatly appreciated.

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  • Strange offset space between <button> as parent container and <div> as child.

    - by Maxja
    I need to decorate a standard html button. The base element I took <button> instead of <input>, cos I decided that the element must be a parent container. And there is child element <div> in it. This <div> element will be been the core element for decoration, and should occupy the entire space of the parent element - button. <button> <div>*decoration goes here*</div> </button> And within Cascading Style Sheets it might be looks like this: css button { margin: 0; border: 0; padding: 0; width: *150*px; height: *50*px; position: relative; } div { margin: 0; border: 0; padding: 0; width: 100%; height: 100%; background: *black*; position: absolute; top: 0; left: 0; } html <button type="button"> <div>*decoration goes here*</div> </button> So, Opera(10) is doing well, webkits Chrome(6) and Safari(4) is doing also well, but Internet Explorer(8) is bad - DOM Inspector shows some strange Offset space in top and left, FireFox(3) is also bad - DOM Inspector shows that <div> get some negative value in css-property right: and bottom:. Even if this property will set to zero(0) DOM-Inspector still shows same negative value. I almost broke my brain. Help me, solve this problem, please!

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  • [^.] causing headache in RewriteRule

    - by Ollie2893
    I am struggling with a very basic regex problem in my .htaccess file that I hope someone may be able to shed some light on. The basic premise is that I would like to teach Apache to switch any .html extension into a .var extension. I had thought that the rule would be positively trivial: RewriteRule ^([^.]+)\.html$ $1.var But the [^.] part simply doesn't work. Bizarrely, it works like so RewriteRule ^([^A-Z]+)\.html$ $1.var I do not understand why this latter rule works. Assume I am looking for a file called "index.html" then $1 should match to "index." and the ".html" bit should actually fail to match. To widen the scope of the question slightly, I am actually racking my brain on how to implement a multi-lingual site. I don't like Apache's MultiView option because it forces upon me a flat directory structure with file extensions that aren't recognizable to many development tools. I could go the .var type-map route but am finding that the default config for Apache doesn't support this all that well either (hence my excursions into regex land). So while I am using mod_rewrite, I am thinking that I might go the whole hog: whenever a request for a name.html file is received and this file does not exist, check whether there exists a XX/name.html file instead, where "XX" is the language code according to the user's preferences. This would give me a neater directory structure, though it does perhaps not perform as well as the .var approach in a situation where the language preference of the user's browser is not supported in by my site (in which situation .var would substitute EN or similar). Any thoughts? Thanks.

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  • Saving and restoring OpenGL model-view

    - by Tom
    I am a new-comer to OpenGL, and much of it remains mysterious to my feeble brain. I have been studying the NeHe demos as well as the Red Book. I am writing an Android application that displays the Earth in the center of the screen. The user can rotate the Earth about any axis (much like a very simple "Google Earth"). This code is working (I based it on the NeHe examples). Now I want to add a feature; the user should be able to save the current model orientation, then later return to that same orientation. For example, the user may save the Earth orientation such that the viewer is looking down at her hometown, and north-east is "up". How do I do this with OpenGL-ES? To capture and save the current orientation, my code could get the current model-view transformation matrix - I think I understand how to do that. But later on how do I apply that saved matrix to restore the view?

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  • MySQL connection attempt works fine in 5.2.9 but not in 5.3.0 - Help?

    - by Rich
    Hi, I'm having trouble making a secondary MySQL connection (to a separate, external DB) in my code. It works fine in PHP 5.2.9 but fails to connect in PHP 5.3.0. I'm aware of (at least some) of the changes needed to make successful MySQL connections in the newer version of PHP, and have succeeded before, so I'm not sure why it isn't working this time. I already have a db connection open to a local database. This function below is then used to make an additional connection to a separate, remote directory. The included config file simply contains the external database details (host, user, pass and name). I have checked and it is being included correctly. function connectDP() { global $dpConnection; include("secondary_db_config.php); $dpConnection = mysql_connect($dp_dbHost, $dp_dbUser, $dp_dbPass, true) or DIE("ERROR: Unable to connect to Deployment Platform"); mysql_select_db($dp_dbName, $dpConnection) or DIE("ERROR 006: Unable to select Deployment Platform Database"); } I then attempt to make this new connection simply by calling this function externally: connectDP(); But when loading the page (in 5.3.0), I get the message: ERROR: Unable to connect to Deployment Platform I'm using the optional new_link flag boolean as the fourth argument in the mysql_connect() function and it's still not working. I've been wracking my brain this morning trying to figure out why this connection doesn't work (while I've done something very similar elsewhere to a separate second database that does work). Any help would be appreciated. Thanks! Rich

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  • ReplaceAll not working as expected

    - by Tim Kemp
    Still early days with Mathematica so please forgive what is probably a very obvious question. I am trying to generate some parametric plots. I have: ParametricPlot[{ (a + b) Cos[t] - h Cos[(a + b)/b t], (a + b) Sin[t] - h Sin[(a + b)/b t]}, {t, 0, 2 \[Pi]}, PlotRange -> All] /. {a -> 2, b -> 1, h -> 1} No joy: the replacement rules are not applied and a, b and h remain undefined. If I instead do: Hold@ParametricPlot[{ (a + b) Cos[t] - h Cos[(a + b)/b t], (a + b) Sin[t] - h Sin[(a + b)/b t]}, {t, 0, 2 \[Pi]}, PlotRange -> All] /. {a -> 2, b -> 1, h -> 1} it looks like the rules ARE working, as confirmed by the output: Hold[ParametricPlot[{(2 + 1) Cos[t] - 1 Cos[(2 + 1) t], (2 + 1) Sin[t] - 1 Sin[(2 + 1) t]}, {t, 0, 2 \[Pi]}, PlotRange -> All]] Which is what I'd expect. Take the Hold off, though, and the ParametricPlot doesn't work. There's nothing wrong with the equations or the ParametricPlot itself, though, because I tried setting values for a, b and h in a separate expression (a=2; b=1; h=1) and I get my pretty double cardoid out as expected. So, what am I doing wrong with ReplaceAll and why are the transformation rules not working? This is another fundamentally important aspect of MMA that my OOP-ruined brain isn't understanding. I tried reading up on ReplaceAll and ParametricPlot and the closest clue I found was that "ParametricPlot has attribute HoldAll and evaluates f only after assigning specific numerical values to variables" which didn't help much or I wouldn't be here. Thanks.

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  • Monads with Join() instead of Bind()

    - by MathematicalOrchid
    Monads are usually explained in turns of return and bind. However, I gather you can also implement bind in terms of join (and fmap?) In programming languages lacking first-class functions, bind is excruciatingly awkward to use. join, on the other hand, looks quite easy. I'm not completely sure I understand how join works, however. Obviously, it has the [Haskell] type join :: Monad m = m (m x) - m x For the list monad, this is trivially and obviously concat. But for a general monad, what, operationally, does this method actually do? I see what it does to the type signatures, but I'm trying to figure out how I'd write something like this in, say, Java or similar. (Actually, that's easy: I wouldn't. Because generics is broken. ;-) But in principle the question still stands...) Oops. It looks like this has been asked before: Monad join function Could somebody sketch out some implementations of common monads using return, fmap and join? (I.e., not mentioning >>= at all.) I think perhaps that might help it to sink in to my dumb brain...

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  • Is there a faster method to match an arbitrary String to month name in Java

    - by jonc
    Hello, I want to determine if a string is the name of a month and I want to do it relatively quickly. The function that is currently stuck in my brain is something like: boolean isaMonth( String str ) { String[] months = DateFormatSymbols.getInstance().getMonths(); String[] shortMonths = DateFormatSymbols.getInstance().getShortMonths(); int i; for( i = 0; i<months.length(); ++i;) { if( months[i].equals(str) ) return true; if( shortMonths[i].equals(str ) return true; } return false; } However, I will be processing lots of text, passed one string at a time to this function, and most of the time I will be getting the worst case of going through the entire loop and returning false. I saw another question that talked about a Regex to match a month name and a year which could be adapted for this situation. Would the Regex be faster? Is there any other solution that might be faster?

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  • Basic formatting. sed, or cut, or what?

    - by dsclough
    Very new to this whole Unix thing. I'm currently using korn shell to try and format some lines of text. My input has a couple of lines that look something like this Date/Time :- Monday June 03 00:00:00 EDT 2013 Host Name :- HostNameHere PIDS :- NumbersNLetters Product Name :- ProductName The desired output would be as follows: Date/Time="Monday June 03 00:00:00 EDT 2013" HostName="HostNameHere" PIDS="NumbersNLetters" ProductName="ProductName" So, I need to get rid of any spaces in the leftmost column, and throw everything in the rightmost column between quotations. I've looked at the cut command, and got this far: Cut -f 1,2 -d - Which might produce a result like Date/Time:Monday June 03 00:00:00 EDT 2013, which is close to what I want, but not quite. I wasn't sure if cut could let me add parentheses, and it doesn't look like I can remove spaces that way either. sed seems like it might be closer to the answer, but I wasn't able to find through googling how I might just look for any pattern and not a specific one. I apologize for the incredibly basic question, but reading documentation only gets you so far before your brain starts to ache... If there are any better resources I should be looking at I would be happy to get pointed in the right direction. Thanks!

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  • Counting character count in Access database column ins SQL

    - by jzr
    Good Evening. My problem is possibly very easy, I just have spent some time researching now and probably have a brain lock and unable to solve this, help would be much appreciated. database structure: col1 col2 col3 col4 ==================== 1233+4566+ABCD+CDEF 1233+4566+ACD1+CDEF 1233+4566+D1AF+CDEF I need to count character count in col3, wanted result in from the previous table would be: char count =========== A 3 B 1 C 2 D 3 F 1 1 2 is this possible to achieve by using SQL only? at the moment I am thinking of passing a parameter in to SQL query and count the characters one by one and then sum, however I did not start the VBA part yet, and frankly wouldn't want to do that. this is my query at the moment: PARAMETERS X Long; SELECT First(Mid(TABLE.col3,X,1)) AS [col3 Field], Count(Mid(TABLE.col3,X,1)) AS Dcount FROM TEST GROUP BY Mid(TABLE.col3,X,1) HAVING (((Count(Mid([TABLE].[col3],[X],1)))>=1)); ideas and help are much appreciated, as being said this is probably very for some of your guys, I don't usually work with access and SQL. Thanks.

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