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  • How to find minimum of nonlinear, multivariate function using Newton's method (code not linear algeb

    - by Norman Ramsey
    I'm trying to do some parameter estimation and want to choose parameter estimates that minimize the square error in a predicted equation over about 30 variables. If the equation were linear, I would just compute the 30 partial derivatives, set them all to zero, and use a linear-equation solver. But unfortunately the equation is nonlinear and so are its derivatives. If the equation were over a single variable, I would just use Newton's method (also known as Newton-Raphson). The Web is rich in examples and code to implement Newton's method for functions of a single variable. Given that I have about 30 variables, how can I program a numeric solution to this problem using Newton's method? I have the equation in closed form and can compute the first and second derivatives, but I don't know quite how to proceed from there. I have found a large number of treatments on the web, but they quickly get into heavy matrix notation. I've found something moderately helpful on Wikipedia, but I'm having trouble translating it into code. Where I'm worried about breaking down is in the matrix algebra and matrix inversions. I can invert a matrix with a linear-equation solver but I'm worried about getting the right rows and columns, avoiding transposition errors, and so on. To be quite concrete: I want to work with tables mapping variables to their values. I can write a function of such a table that returns the square error given such a table as argument. I can also create functions that return a partial derivative with respect to any given variable. I have a reasonable starting estimate for the values in the table, so I'm not worried about convergence. I'm not sure how to write the loop that uses an estimate (table of value for each variable), the function, and a table of partial-derivative functions to produce a new estimate. That last is what I'd like help with. Any direct help or pointers to good sources will be warmly appreciated. Edit: Since I have the first and second derivatives in closed form, I would like to take advantage of them and avoid more slowly converging methods like simplex searches.

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  • Approaches to create a nested tree structure of NSDictionaries?

    - by d11wtq
    I'm parsing some input which produces a tree structure containing NSDictionary instances on the branches and NSString instance at the nodes. After parsing, the whole structure should be immutable. I feel like I'm jumping through hoops to create the structure and then make sure it's immutable when it's returned from my method. We can probably all relate to the input I'm parsing, since it's a query string from a URL. In a string like this: a=foo&b=bar&a=zip We expect a structure like this: NSDictionary { "a" => NSDictionary { 0 => "foo", 1 => "zip" }, "b" => "bar" } I'm keeping it just two-dimensional in this example for brevity, though in the real-world we sometimes see var[key1][key2]=value&var[key1][key3]=value2 type structures. The code hasn't evolved that far just yet. Currently I do this: - (NSDictionary *)parseQuery:(NSString *)queryString { NSMutableDictionary *params = [NSMutableDictionary dictionary]; NSArray *pairs = [queryString componentsSeparatedByString:@"&"]; for (NSString *pair in pairs) { NSRange eqRange = [pair rangeOfString:@"="]; NSString *key; id value; // If the parameter is a key without a specified value if (eqRange.location == NSNotFound) { key = [pair stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding]; value = @""; } else { // Else determine both key and value key = [[pair substringToIndex:eqRange.location] stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding]; if ([pair length] > eqRange.location + 1) { value = [[pair substringFromIndex:eqRange.location + 1] stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding]; } else { value = @""; } } // Parameter already exists, it must be a dictionary if (nil != [params objectForKey:key]) { id existingValue = [params objectForKey:key]; if (![existingValue isKindOfClass:[NSDictionary class]]) { value = [NSDictionary dictionaryWithObjectsAndKeys:existingValue, [NSNumber numberWithInt:0], value, [NSNumber numberWithInt:1], nil]; } else { // FIXME: There must be a more elegant way to build a nested dictionary where the end result is immutable? NSMutableDictionary *newValue = [NSMutableDictionary dictionaryWithDictionary:existingValue]; [newValue setObject:value forKey:[NSNumber numberWithInt:[newValue count]]]; value = [NSDictionary dictionaryWithDictionary:newValue]; } } [params setObject:value forKey:key]; } return [NSDictionary dictionaryWithDictionary:params]; } If you look at the bit where I've added FIXME it feels awfully clumsy, pulling out the existing dictionary, creating an immutable version of it, adding the new value, then creating an immutable dictionary from that to set back in place. Expensive and unnecessary? I'm not sure if there are any Cocoa-specific design patterns I can follow here?

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  • stringtemplate .net dynamic object

    - by Mark Milford
    Hi I am using string template to render some content, but the content may be variable so not sure how to pass it in (using .net / c#) Basic idea is I have a List which need to end up as parameters, e.g. List<KeyValuePair<string, object>> ret = new List<KeyValuePair<string, object>>(); ret.Add(new KeyValuePair<string, object>("elem1", true)); ret.Add(new KeyValuePair(string, object>("elem2", false)); Now I want these to show up in string template as: $item.elem1$ $item.elem2$ I can get them to be $elem1$ or $elem2$ but i need them inside of a structure. So I in effect need to convince the string template setAttribute that I'm passing in an object with properties elem1 and elem2 when in fact I have a List of KeyValuePairs. Thanks

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  • Session variable getting lost using Firefox, works in IE

    - by user328422
    I am setting a Session variable in an HttpHandler, and then getting its value in the Page_load event of an ASPX page. I'm setting it using public void ProcessRequest(HttpContext context) { HttpPostedFile file = context.Request.Files["Filedata"]; context.Session["WorkingImage"] = file.FileName; } (And before someone suggests that I check the validity of file.FileName, this same problem occurs if I hard-code a test string in there.) It's working just fine in IE, but in Firefox the Session Variable is not found, getting the "Object reference not set to an instance of an object" error in the following code: protected void Page_Load(object sender, EventArgs e) { string loc = Session["WorkingImage"].ToString(); } Has anyone encountered this problem - and hopefully come up with a means for passing the session variable?

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  • How do I setup a custom Gem.path using JRuby::Rack?

    - by Ben Hogan
    Hi Nick et al, I've been having some fun looking at to source code of JRuby-Rack and Rubygems to try to figure out how to solve a org.jruby.rack.RackInitializationException: no such file to load -- compass in my rackup script cased by require 'compass'. I'm passing in a custom 'gem.path' as a servlet init parameter and it is being correctly picked up by jruby-rack as far as I can tell by debugging in my rackup script: ENV['GEM_PATH'] => '/foo/lib/.jruby/gems' (expected) but rubygems seems to be broken: Gem.path => file:/foo/lib/jruby-complete-1.4.0.jar!/META-INF/jruby.home/lib/ruby/gems/1.8 I'm not sure why rubygems has not adjusted it's gem_path nor the LOAD_PATH, thus breaking require? Thanks again, I'm still a newbie at ruby, jruby, rack and sinatra. Any pointers in the right direction appreciated! Ben

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  • Using embedded resources in Silverlight (4) - other cultures not being compiled

    - by Andrei Rinea
    I am having a bit of a hard time providing localized strings for the UI in a small Silverlight 4 application. Basically I've put a folder "Resources" and placed two resource files in it : Statuses.resx Statuses.ro.resx I do have an enum Statuses : public enum Statuses { None, Working } and a convertor : public class StatusToMessage : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { if (!Enum.IsDefined(typeof(Status), value)) { throw new ArgumentOutOfRangeException("value"); } var x = Statuses.None; return Statuses.ResourceManager.GetString(((Status)value).ToString(), Thread.CurrentThread.CurrentUICulture); } public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); } } in the view I have a textblock : <TextBlock Grid.Column="3" Text="{Binding Status, Converter={StaticResource StatusToMessage}}" /> Upon view rendering the converter is called but no matter what the Thread.CurrentThread.CurrentUICulture is set it always returns the default culture value. Upon further inspection I took apart the XAP resulted file, taken the resulted DLL file to Reflector and inspected the embedded resources. It only contains the default resource!! Going back to the two resource files I am now inspecting their properties : Build action : Embedded Resource Copy to output directory : Do not copy Custom tool : ResXFileCodeGenerator Custom tool namespace : [empty] Both resource (.resx) files have these settings. The .Designer.cs resulted files are as follows : Statuses.Designer.cs : //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace SilverlightApplication5.Resources { using System; /// <summary> /// A strongly-typed resource class, for looking up localized strings, etc. /// </summary> // This class was auto-generated by the StronglyTypedResourceBuilder // class via a tool like ResGen or Visual Studio. // To add or remove a member, edit your .ResX file then rerun ResGen // with the /str option, or rebuild your VS project. [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "4.0.0.0")] [global::System.Diagnostics.DebuggerNonUserCodeAttribute()] [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()] internal class Statuses { // ... yadda-yadda Statuses.ro.Designer.cs [empty] I've taken both files and put them in a console application and they behave as expected in it, not like in this silverlight application. What is wrong?

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  • asp.net profiles not working in global.asax?

    - by Martin Ongtangco
    Hello, i have a class that returns the parameters i've set in the profile properties in web.config. It works great on classes, but I cannot seem to make it work under the Global.asax? Here is how I get the parameter: public static string MissingPagePath { get { return HttpContext.Current.Profile.GetPropertyValue("MissingPage").ToString(); } } Help!

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  • Mouse position in xaml - wpf

    - by Simon Fox
    Hi all Is it possible to specify the position of the mouse as the value of the Parameter property of a Command in XAML. Something like the following: <UserControl.ContextMenu> <ContextMenu> <MenuItem Header="Create Link" Command="{Binding CreateLink}" CommandParameter="{Binding Mouse.Position}" > </MenuItem> </ContextMenu> </UserControl.ContextMenu>

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  • What is the best way to set up a PHP development environment on a Mac?

    - by Edward Tanguay
    When I do PHP, I use XAMPP to set up a development environment on Windows, then upload to Linux servers, works very well. I'm now passing on a PHP project to a person who has a Mac so he needs a local PHP dev environment. I noticed XAMPP has a version for Mac which I will recommend. But knowing that Mac is always a bit different, has anyone used any other easy PHP environment setup tool for the Mac, or I could even imagine that Mac solves this issue more elegantly by e.g. having a web server ready to go upon first boot etc. What is the best way to set up a PHP development environment on a Mac?

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  • How to prevent C6284 when using CString::Format?

    - by Sorin Sbarnea
    The following code is generating warning C6284 when compiled with /analyze on MSVC 2008 : object passed as parameter '%s' when string is required in call to function. CString strTmp, str; str = L"aaa.txt" strTmp.Format (L"File: %s", str); I'm looking for a nice solution for this that would not require static_cast

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  • Displaying Video using a Window Handle

    - by fergs
    I'm working on a C# wrapper for Dallmeier camera's and currently have a working wrapper. I can connect to a camera via passing the window handle (in my application its a picture box handle), this is used to send video and messages. Once connected I can then send the StartLiveView command and then a live stream video will be shown in the picture box. Can someone explain how this works by just giving the window handle? And how can I grab an Image from this stream when Picturebox1.Image is null?

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  • ASP.NET MVC3 Custom Membership Provider - The membership provider name specified is invalid.

    - by David Lively
    I'm implementing a custom membership provider, and everything seems to go swimmingly until I create a MembershipUser object. At that point, I receive the error: The membership provider name specified is invalid. Parameter name: providerName In web.config the membership key is <membership defaultProvider="MembersProvider"> <providers> <clear/> <add name="MembersProvider" type="Members.Providers.MembersProvider" connectionStringName="ApplicationServices" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="DeviceDatabase" /> </providers> </membership> When creating the MembershipUser object from my custom User class: public static MembershipUser ToMembershipUser(User user) { MembershipUser member = new MembershipUser ("MembersProvider" , user.Name , user.Id , user.EmailAddress , user.PasswordQuestion , user.Comment , user.IsApproved , user.IsLockedOut , user.DateCreated , user.LastLoginDate ?? DateTime.MinValue , user.LastActivityDate ?? DateTime.MinValue , user.LastPasswordChangedDate ?? DateTime.MinValue , user.LastLockoutDate ?? DateTime.MinValue ); return member; } (I realize I could probably just inherit my User class from MembershipUser, but it's already part of an existing class hierarchy. I honestly think this is the first time I've encountered a legitimate need for for multiple inheritance!) My feeling is that the new MembershipUser(...) providerName parameter is supposed to match what's set in web.config, but, since they match already, I'm at a loss as to how to proceed. Is there a convenient way to get the name of the active membership provider in code? I'm starting to think that using the built-in membership system is overkill and more trouble than it's worth. Edit Not sure if it's relevant, but the custom membership provider class is in a class library, not the main WAP project. Update Here's the contents of the System.Web.Security.Membership.Provider object as show in the VS2010 command window: >eval System.Web.Security.Membership.Provider {Members.Providers.MembersProvider} [Members.Providers.MembersProvider]: {Members.Providers.MembersProvider} base {System.Configuration.Provider.ProviderBase}: {Members.Providers.MembersProvider} ApplicationName: null EnablePasswordReset: true EnablePasswordRetrieval: false MaxInvalidPasswordAttempts: 5 MinRequiredNonAlphanumericCharacters: 0 MinRequiredPasswordLength: 6 PasswordAttemptWindow: 10 PasswordFormat: Function evaluation was aborted. PasswordStrengthRegularExpression: Cannot evaluate expression because debugging information has been optimized away . RequiresQuestionAndAnswer: Cannot evaluate expression because debugging information has been optimized away . RequiresUniqueEmail: Cannot evaluate expression because debugging information has been optimized away .

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  • Why can't I log in with "claimid.com" as an OpenID?

    - by radu-negrila
    Hi, I need to implement a relying party for Open ID in a load balanced environment. Following the suggestions found here I have tried passing null to the OpenIdRelyingParty constructor. The results are somehow not consistent. If I use www.myopenid.com as a provider it works. If I use www.claimid.com as a provider I get the following exception: ProtocolException - No OpenID endpoint found. This exception is thrown on the CreateRequest method call even in a non balanced environment (my local workstation). Any idea what can I do to make it work for both providers ?

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  • Can't debug code using VS 2010 beta 2

    - by Nathan W
    This is really strange and I can't seem to figure out why it won't work. I have a C# dll that is a add on for another program, the main program is not mine or a .Net app so I am starting it with Start external program in the debugging tab and and passing my program as a command line and the program starts and loads my add on however my Visual Studio debugger doesn't step into the debugger and won't hit my break points. I checked the module window and it's not even loaded in there, I used process explorer and had a look at main program and my dll was loaded into the main app. The project is set to debug, symbols to full and still nothing. I created the project in VS 2008 and it worked fine and am now trying to get this to work in VS 2010 and no go. Anyone know what could be causing this?

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  • Multiple constructors in C

    - by meepz
    Hello, I am making a string class in C as a homework and I was wondering how I can make multiple constructors with the same name given the parameter. The commented out area is what I tried to do with results from a few searches but that gives me errors. Pretty much I have some cases where I want to create my new string without any parameter then in other cases create a string with a pointer to character. Here is mystring.h #include <stdio.h> #include <stdlib.h> typedef struct mystring { char * c; int length; int (*sLength)(void * s); char (*charAt)(void * s, int i); int (*compareTo)(void * s1, void * s2); struct mystring * (*concat)(void * s1, void * s2); struct mystring * (*subString)(void * s, int begin, int end); void (*printS)(void * s); } string_t; typedef string_t * String; String newString(char * c); String newString2(); int slength(void * s); char charat(void * S, int i); int compareto(void * s1, void * s2); String concat(void * s1, void * s2); String substring(void * S, int begin, int end); void printstring(void * s); And here is mystring.c #include "mystring.h" String newString(){ } String newString(char * input){ //String newString::newString(char * input) { String s; s = (string_t *) malloc(sizeof(string_t)); s->c = (char *) malloc(sizeof(char) * 20); int i = 0; if (input == NULL){ s->c[0] = '\0'; return s; } while (input[i] != '\0') { s->c[i] = input[i]; i++; } //functions s->sLength = slength; s->charAt = charat; s->compareTo = compareto; s->concat = concat; s->subString = substring; s->printS = printstring; return s; }

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  • setTimeout() not executing

    - by Ben Shelock
    I've got this simple function which displays a message to the user. If I add the timeout parameter it will slide back up automatically if not the user has to click it to get rid. But the timeout bit isn't working. function feedback(text, timeout){ $('#feedback').text(text).slideDown('fast'); $('#feedback').click(function(){ $(this).slideUp(); }); if(timeout){ setTimeout(function(){ $('#feedback').slideup(); }, timeout); } }

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  • DefaultSchedulerService in ASP.NET application

    - by Samir P
    Hi, My project has a requirement to implement look-ahead caching i.e. triggering another request on invokation of a specific request. The following details in short the implementation - HttpModule parses the SOAPRequest and matches entry in a configuration file for look-ahead candidate. If the request matches, it prepares the Parameters dictionary and starts appropriate workflow. Single workflow runtime is used across all requests is ensured through initializing the runtime instance at Application_Start event and stored in Application Dictionary. Using persistence service and DefaultScheduler service. We can't implement windows service model, as current requirement mandates passing the SOAPRequest parameters as arguments. ManualSchedulerService is not in contention due to synchronous nature of it's actual behaviour. Still the performance is pretty bad and product team is not happy. Can anybody suggest me better solution? Thanks, Samir

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  • Simplest possible table entry editing / addition / deletion web toolkit (for use with php)

    - by Dave
    Hi, i'm building a website in php and i have tables presented that i need to allow the user to: 1. add new entry (only one at a time, which should appear as a new modal overlay) 2. delete multiple selected entries from 3. edit an existing entry (only one at one time, in a view similar to 1.) 4. re-arrange entries up and down. One by one is fine. Multiple / Grouping rearrangements are not not needed what jquery / js / anything toolkit would be the SIMPLEST to work with? (of course, i should be able to work with it in php). I did try hacking away at: http://www.ericmmartin.com/projects/simplemodal/ but had a terrible time trying to get it to work on editing some existing data (had problem passing data to it).

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  • VSTS test deployment and invalid assembly culture

    - by Merlyn Morgan-Graham
    I have a DLL that I'm testing, which links to a DLL that has what I think is an invalid value for AssemblyCulture. The value is "Neutral" (notice the upper-case "N"), whereas the DLL I'm testing, and every other DLL in my project, has a value of "neutral" (because they specify AssemblyCulture("")). When I try to deploy the DLL that links to the problem DLL, I get this error in VSTS: Failed to queue test run '...': Culture is not supported. Parameter name: name Neutral is an invalid culture identifier. <Exception>System.Globalization.CultureNotFoundException: Culture is not supported. Parameter name: name Neutral is an invalid culture identifier. at System.Globalization.CultureInfo..ctor(String name, Boolean useUserOverride) at System.Globalization.CultureInfo..ctor(String name) at System.Reflection.RuntimeAssembly.GetReferencedAssemblies(RuntimeAssembly assembly) at System.Reflection.RuntimeAssembly.GetReferencedAssemblies() at Microsoft.VisualStudio.TestTools.Utility.AssemblyLoadWorker.ProcessChildren(Assembly assembly) at Microsoft.VisualStudio.TestTools.Utility.AssemblyLoadWorker.GetDependentAssemblies(String path) at Microsoft.VisualStudio.TestTools.Utility.AssemblyLoadWorker.GetDependentAssemblies(String path) at Microsoft.VisualStudio.TestTools.Utility.AssemblyLoadStrategy.GetDependentAssemblies(String path) at Microsoft.VisualStudio.TestTools.Utility.AssemblyHelper.GetDependentAssemblies(String path, DependentAssemblyOptions options, String configFile) at Microsoft.VisualStudio.TestTools.TestManagement.DeploymentManager.GetDependencies(String master, String configFile, TestRunConfiguration runConfig, DeploymentItemOrigin dependencyOrigin, List`1 dependencyDeploymentItems, Dictionary`2 missingDependentAssemblies) at Microsoft.VisualStudio.TestTools.TestManagement.DeploymentManager.DoDeployment(TestRun run, FileCopyService fileCopyService) at Microsoft.VisualStudio.TestTools.TestManagement.ControllerProxy.SetupTestRun(TestRun run, Boolean isNewTestRun, FileCopyService fileCopyService, DeploymentManager deploymentManager) at Microsoft.VisualStudio.TestTools.TestManagement.ControllerProxy.SetupRunAndListener(TestRun run, FileCopyService fileCopyService, DeploymentManager deploymentManager) at Microsoft.VisualStudio.TestTools.TestManagement.ControllerProxy.QueueTestRunWorker(Object state)</Exception> Even if I don't link to the DLL (in my VSTS wrapper test, or in the NUnit test), as soon as I add it in my GenericTest file (I'm wrapping NUnit tests), I get that exception. We don't have the source for the problem DLL, and it is also code signed, so I can't solve this by recompiling. Is there a way to skip deploying the dependencies of a DLL DeploymentItem, to fix or disable the culture check, or to work around this by convoluted means (maybe somehow embed the assembly)? Is there a way to override the value for the culture, short of hacking the DLL (and removing code signing so the hack works)? Maybe with an external manifest? Any correct solution must work without weird changes to production code. We can't deploy a hacked DLL, for example. It also must allow the DLL to be instrumented for code coverage. Additional note: I do get a linker warning when compiling the DLL under test that links to the problem DLL, but this hasn't broken anything but VSTS, and multiple versions have shipped.

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  • Int or NSInteger as object for method argument. Objective-C

    - by sergiobuj
    Hi. I'm having some trouble passing a number as an argument for a method: -(void) meth2:(int)next_int; And to call that method i need this: int next_int = 1; [self performSelectorOnMainThread:@selector(meth2:) withObject:next_int waitUntilDone:NO]; //update next_int and call meth2 again at this point i get a "pointer from integer without a cast" error, and would happen the same with a NSInteger. A NSNumber is not useful because it's immutable and i need to change the value constantly. Any Idea how can i do this? Thanks.

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  • Intersection point in silverlight/wpf

    - by Andrei Neagu
    Hello, Given a path like this one : <Path Stretch="Fill" Stroke="#FFD69436" Data="M 0,20 L 22.3,20 L 34,0 L 44.7,20 L 68,20 L 55.8,40 L 68,60 L 44.7,60 L 34,80 L 22.3,60 L 0,60 L 11.16,40 L 0,20 Z"> <Path.Fill> <LinearGradientBrush StartPoint="0,0" EndPoint="0,1"> <LinearGradientBrush.GradientStops> <GradientStop Color="#FFFFFF" Offset="0" /> <GradientStop Color="Orange" Offset="1" /> </LinearGradientBrush.GradientStops> </LinearGradientBrush> </Path.Fill> </Path> How can I get the point that is at the edge of this figure at any angle? Lets say that I want the intersection point between the edge of this figure and a line passing through the center of this figure, at the 30 degrees angle with the OX axe? thanks.

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  • How to display over state of a SimpleButton at up state

    - by Hasan Gürsoy
    I have a menu with button objects in As3. I want to display the page where user is and for this I must show buttons' over state (which is mc) when flash loads. I'm sending the page parameter to flash. I just need to play the movie clip inside the specific button. Looking for something like: btn1.m1.gotoAndPlay(1); or btn1.m1.play();

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  • TTNavigator three20 openURLAction

    - by disp
    I'm new to three20 and trying to find my way through the TTNavigator class. I try to push to a new view via the URL system. So I used openURL: animated: method which works just fine, but it's deprecated, and I know that I should use openURLAction instead, but this has no animated: parameter. Am I missing something?

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