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• Plotting a graph with GD

  - by Nayena

  Here it goes. I have been thinking about this for a long time, and havent really been able to put up a proper way to do it yet. I havent implemented anything yet, as im still designing the thing. The idea is that i crawl a website for internal links, i got this settled, its easy, but after the crawling, i end up with an array with lots of links, and how many times those particular link appears on the site that i crawled (and how they're connected). With this huge array, i want to draw a graph somehow. Assuming i can handle the data correctly, the real question here is how i can draw this in a image by the use of the GD library. I figured if theres less than 12 elements, i can align them up on a unit circle spacing them up as a circle and then connecting them accordingly, so anything up to 12 elements shouldn't be a problem, but if theres more than 12, it could be awesome getting them lined up like this Or well, thats just a rough drawing, but i guess its just to prove a point. So i'm here looking for guidance or tips towards getting the math down to getting the stuff lined up in a good way. I have previously made bar-graphs, so i have little experience doing math with GD. If possible, id prefer not using some plotter-library - in the end, it gives me a better understanding on how things are supposed to be.

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• Apache Virtual host Subdomains points to same directory

  - by Jakobud

  I have setup subdomains using Apache before and have never really ran into any big problems. But with this (I believe Centos) server that is one of my clients, I'm not understanding what I'm doing wrong. Here is the .conf that apache is loading: Listen 80 NameVirtualHost *:80 <VirtualHost *:80> ServerName www.thedomain.com DocumentRoot /u1/thedomain.com/public RailsEnv production </VirtualHost> <VirtualHost *:80> ServerName subdomain.thedomain.com DocumentRoot /u1/subdomain.thedomain.com/public_html </VirtualHost> When I access either the primary or subdomain addresses, they both point to the primary www.thedomain.com content. Any thoughts? UPDATE: Yes I did a configtest and graceful after making the changes.

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• Modify existing struct alignment in Visual C++

  - by Crend King

  Is there a way to modify the member alignment of an existing struct in Visual C++? Here is the background: I use an 3rd-party library, which uses several structs. To fill up the structs, I pass the address of the struct instance to some functions. Unfortunately, the functions only returns unaligned buffer, so that data of some members are always wrong. /Zp is out of choice, since it breaks the other parts of the program. I know #pragma pack modifies the alignment of the following struct, but I do not want to copy the structs into my code, for the definitions in the library might change in the future. Sample code: test.h: struct am_aligned { BYTE data1[10]; ULONG data2; }; test.cpp: include "test.h" // typedef alignment(1) struct am_aligned am_unaligned int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { char buffer[20] = {}; for (int i = 0; i < sizeof(unaligned_struct); i++) { buffer[i] = i; } am_aligned instance = *(am_aligned*) buffer; return 0; } instance.data2 is 0x0f0e0d0c, while 0x0d0c0b0a is desired. The commented line does not work of course. Thanks for help!

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• Finding What You Need in R: function arguments/parameters from outside the function's package

  - by doug

  Often in R, there are a dozen functions scattered across as many packages--all of which have the same purpose but of course differ in accuracy, performance, theoretical rigor, and so on. How do you gather all of these in one place before you start your task? So for instance: the generic plot function. Setting secondary ticks is much easier (IMHO) using a function outside of the base package, minor.tick(nx=n, ny=n, tick.ratio=n), found in Hmisc. Of course, that doesn't show up in plot's docstring. Likewise, the data-input arguments to 'plot' can be supplied by an object returned from the function 'hexbin', again, from a library outside of the base installation (where 'plot' resides). What would be great obviously is a programmatic way to gather these function arguments from the various libraries and put them in a single namespace. edit: (trying to re-state my example just above more clearly:) the arguments to plot supplied in the base package for, e.g., setting the axis tick frequency are xaxp/yaxp; however, one can also set a/t/f via a function outside of the base package, again, as in the minor.tick function from the Hmisc package--but you wouldn't know that just from looking at the plot method signature. Is there a meta function in R for this? So far, as i come across them, i've been manually gathering them in a TextMate 'snippet' (along with the attendant library imports). This isn't that difficult or time consuming, but i can only update my snippet as i find out about these additional arguments/parameters. Is there a canonical R way to do this, or at least an easier way? Just in case that wasn't clear, i am not talking about the case where multiple packages provide functions directed to the same statistic or view (e.g., 'boxplot' in the base package; 'boxplot.matrix' in gplots; and 'bplots' in Rlab). What i am talking is the case in which the function name is the same across two or more packages.

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• how to redirect user depending on user type at time of login (codeignitor)

  - by Anam Tahir

  im facing problem while redirecting my user according to its type. how can do it here's my code plz suggest how to do it. <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); class VerifyLogin extends CI_Controller { function __construct() { parent::__construct(); } function index() { $this->load->model('user','',TRUE); //This method will have the credentials validation $this->load->library('form_validation'); $this->load->library('session'); $this->form_validation->set_rules('username', 'Username','trim|required|xss_clean'); $this->form_validation->set_rules('password', 'Password' 'trim|required|xss_clean|callback_check_database'); if($this->form_validation->run() == FALSE) { //Field validation failed.&nbsp; User redirected to login page validation_errors(); $this->load->view('error'); } else { //Go to private area basically here i want to redirect if user is admin then redirect to admin page else redirect to home how can i do this ??? redirect('home', 'refresh'); } } function check_database($password) { //Field validation succeeded.&nbsp; Validate against database $username = $this->input->post('username'); //query the database $result = $this->user->login($username, $password); if($result) { $sess_array = array(); foreach($result as $row) { $sess_array = array( 'id' => $row->id, 'username' => $row->username ); $this->session->set_userdata('logged_in', $sess_array); } return TRUE; } else { $this->form_validation->set_message('check_database', 'Invalid username or password'); return false; } } } ?>

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• Mail Stuck in Backend Exchange Queue

  - by Kyle Brandt

  I have a message that has and is stuck in a queue on my backend mail server. The queue is: Internet Mail SMTP Connector (MY_FRONT_END_SERVER_NAME)-524350ff... It is in state retry with 183 failures. It is only one message and all other mail is flowing. The message is not particularly large. My limited understanding, a guess really, is that this message should get handed off to the front end mail server and sent to the remote hosts for which it is destined, so it should even matter if the remote host is up. However, I can telnet to the smtp provider of that host. How can I find out why it is stuck in this queue, and can I force it out somehow (unfreeze doesn't help me)?

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• GNU C++ how to check when -std=c++0x is in effect?

  - by TerryP

  My system compiler (gcc42) works fine with the TR1 features that I want, but trying to support newer compiler versions other than the systems, trying to accessing TR1 headers an #error demanding the -std=c++0x option because of how it interfaces with library or some hub bub like that. /usr/local/lib/gcc45/include/c++/bits/c++0x_warning.h:31:2: error: #error This file requires compiler and library support for the upcoming ISO C++ standard, C++0x. This support is currently experimental, and must be enabled with the -std=c++0x or -std=gnu++0x compiler options. Having to supply an extra switch is no problem, to support GCC 4.4 and 4.5 under this system (FreeBSD), but obviously it changes the picture! Using my system compiler (g++ 4.2 default dialect): #include <tr1/foo> using std::tr1::foo; Using newer (4.5) versions of the compiler with -std=c++0x: #include <foo> using std::foo; Is there anyway using the pre processor, that I can tell if g++ is running with C++0x features enabled? Something like this is what I'm looking for: #ifdef __CXX0X_MODE__ #endif but I have not found anything in the manual or off the web. At this rate, I'm starting to think that life would just be easier, to use Boost as a dependency, and not worry about a new language standard arriving before TR4... hehe.

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• problem finding a header with a c++ makefile

  - by Max

  Hi. I've started working with my first makefile. I'm writing a roguelike in C++ using the libtcod library, and have the following hello world program to test if my environment's up and running: #include "libtcod.hpp" int main() { TCODConsole::initRoot(80, 50, "PartyHack"); TCODConsole::root->printCenter(40, 25, TCOD_BKGND_NONE, "Hello World"); TCODConsole::flush(); TCODConsole::waitForKeypress(true); } My project directory structure looks like this: /CppPartyHack ----/libtcod-1.5.1 # this is the libtcod root folder --------/include ------------libtcod.hpp ----/PartyHack --------makefile --------partyhack.cpp # the above code (while we're here, how do I do proper indentation? Using those dashes is silly.) and here's my makefile: SRCDIR = . INCDIR = ../libtcod-1.5.1/include CFLAGS = $(FLAGS) -I$(INCDIR) -I$(SRCDIR) -Wall CC = gcc CPP = g++ .SUFFIXES: .o .h .c .hpp .cpp $(TEMP)/%.o : $(SRCDIR)/%.cpp $(CPP) $(CFLAGS) -o $@ -c $< $(TEMP)/%.o : $(SRCDIR)/%.c $(CC) $(CFLAGS) -o $@ -c $< CPP_OBJS = $(TEMP)partyhack.o all : partyhack partyhack : $(CPP_OBJS) $(CPP) $(CPP_OBJS) -o $@ -L../libtcod-1.5.1 -ltcod -ltcod++ -Wl,-rpath,. clean : \rm -f $(CPP_OBJS) partyhack I'm using Ubuntu, and my terminal gives me the following errors: max@max-desktop:~/Desktop/Development/CppPartyhack/PartyHack$ make g++ -c -o partyhack.o partyhack.cpp partyhack.cpp:1:23: error: libtcod.hpp: No such file or directory partyhack.cpp: In function ‘int main()’: partyhack.cpp:5: error: ‘TCODConsole’ has not been declared partyhack.cpp:6: error: ‘TCODConsole’ has not been declared partyhack.cpp:6: error: ‘TCOD_BKGND_NONE’ was not declared in this scope partyhack.cpp:7: error: ‘TCODConsole’ has not been declared partyhack.cpp:8: error: ‘TCODConsole’ has not been declared make: * [partyhack.o] Error 1 So obviously, the makefile can't find libtcod.hpp. I've double checked and I'm sure the relative path to libtcod.hpp in INCDIR is correct, but as I'm just starting out with makefiles, I'm uncertain what else could be wrong. My makefile is based off a template that the libtcod designers provided along with the library itself, and while I've looked at a few online makefile tutorials, the code in this makefile is a good bit more complicated than any of the examples the tutorials showed, so I'm assuming I screwed up something basic in the conversion. Thanks for any help.

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• Why is hosted storage so expensive?

  - by Mark Henderson

  There are many questions on Server Fault asking why server storage is so expensive. e.g. Why do I have to pay 50 bucks a month per extra gigabyte of storage or Our file server is always running out of space, why doesn't our sysadmin just throw an extra 1TB drive in there? These questions usually come from people who lack an understanding of how enterprise-level storage works and what influences the price. This question is designed to be the "question to end all questions" regarding the price of enterprise storage.

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• C++/Win32 : XP Visual Styles - no controls are showing up?

  - by mrl33t

  Okay, so i'm pretty new to C++ & the Windows API and i'm just writing a small application. I wanted my application to make use of visual styles in both XP, Vista and Windows 7 so I added this line to the top of my code: #pragma comment(linker,"\"/manifestdependency:type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"") It seemed to work perfectly on my Windows 7 machine and also Vista machine. But when I tried the application on XP the application wouldn't load any controls (e.g. buttons, labels etc.) - not even messageboxes would display. This image shows a small test application which i've just put together to demonstrate what i'm trying to explain: http://img704.imageshack.us/img704/2250/myapp.png In this test application i'm not using any particularly fancy or complicated code. I've effectively just taken the most basic sample code from the MSDN Library (http://msdn.microsoft.com/en-us/library/ff381409.aspx) and added a section to the WM_CREATE message to create a button: MyBtn = CreateWindow(L"Button", L"My Button", BS_PUSHBUTTON | WS_CHILD | WS_VISIBLE, 25, 25, 100, 30, hWnd, NULL, hInst, 0); But I just can't figure out what's going on and why its not working. Any ideas guys? Thank you in advanced. (By the way the application works in XP if i remove the manifest section from the top - obviously without visual styles though. I should also probably mention that the app was built using Visual C++ 2010 Express on a Windows 7 machine - if that makes a difference?)

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• Creating a web application that can be extended by plugins/modules

  - by Adam Pope

  I'm currently involved with developing a C# CMS-like web application which will be used to standardise our development of websites. From the outset, the idea has been to keep the core as simple as possible to avoid the complexity and menu/option overload that blights many CMS systems. This simple core is now complete and working very well. We envisisaged that the system would be able to accept plugins or modules which would extend the core functionality to suit a given projects needs. These would also be re-usable across projects. For example, a basic catalogue and shopping basket might be needed. All the code for such extensions should be in seperate assemblies. They should be able to provide their own admin interfaces and front-end code from this library. The system should search for available plugins and give the admin user the option to enable/disable the feature. (This is all very much like WordPress plugins) It is crucial that we attack this problem in the correct way, so I'm trying to perform as much due dilligence as possible before jumping in. I am aware of the Plugin Pattern (http://msdn.microsoft.com/en-us/library/ms972962.aspx) and have read some articles on it's use. It seems reasonable but I'm not convinced it's necessarily the correct/best technique for this situation. It seems more suited to processing applications (image/audio manipulation, maths etc). Are there any other options for achieving this kind of UI extensibility functionality? Or is the plugin pattern the way to go? I'd also be interested if anybody has links to articles that explain using the plugin pattern for this purpose?

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• Apache redirection problem!!!!

  - by vikas

  Hi guys, I am setting up a pre-built website built in php. The site was actually hosted on the linux server. Now I am trying to set it up on a Window machine with WAMP server. In this website almost every page request passes through a particular file called redirect(which is basically a php file without extension). Now the problem is that when I inspected the configuration(httpd.conf, apache.conf,.htaccess, vhost.conf etc) of the apache server on the linux machine, I nowhere found the redirect rules for doing so. Neither mod_rewrite nor mod_alias rules for this redirection were found there. But is still redirects the request properly. I also noticed that Zend Framework library is there in the exact same directory where the redirect file is. This library is included in the include_path in php.ini. However, the web site is still not developed using Zend MVC and I have seen NO proof of ZEND being used there. So I am really confused how this redirection is working there? I am unable to set up this on window machine without rewrite rules of mod_rewrite or mod_alias. Do you guys know any alternative of both the said modules for redirection? I know the site is really weird, but i have to set it up. :) Thanks in advance for your help.

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• After deleting a local machines offline file cache, the same user's "my documents" no longer redirects to the network location.

  - by stead1984

  One of my apprentices was tasked with clearing out unused local profiles and clearing the offline file cache. After he cleared the offline file cache and rebooted the machine, he would log in as himself and no longer have his "my documents" redirected to the set network location. More over this seemed to then affect ANY other networked machine he logged into, except his own laptop. All our standard workstations run Windows XP Service Pack 3, the apprentice's laptop runs Windows 7 Professional. I can understand how clearing the offline file cache after deleting old local profiles could cause this issue but draw a complete blank as to why it would affect all networked machines. It's a strange one so this question may be a little hard to understand so any questions or further understanding required please ask.

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• Can I redeploy Citrix Xencenter Images in Amazon EC2?

  - by Mike Pinch

  Okay - I'm running Citrix Xencenter in my datacenter. My understanding is that Amazon EC2 is a very customized flavor of Xencenter. Based on that, I would like to know whether there is a method to utilize the .VHD disk images generated by Citrix Xencenter in the Amazon EC2 cloud. I realize that I can install tools into the OS and make my own images but that is not what I'm looking for. I'd like the efficiency of taking the images and redeploying them, or at least converting then redeploying. I basically would like to have all my backups running in the cloud, so that is my motivation.

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• How to change tab background on viewpagerindicator tabs?

  - by user1736277

  I am using ViewpagerIndicator library by Jake Wharton. I am using the tabs code in conjunction with the ActionBarSherlock library. Everything works fine, but I'm trying to style the background of the tabs and can't figure out how. I would like a dark action bar with dark tabs and light fragments (tab content). The base theme I am using is Theme.Sherlock.Light.DarkActionBar. I extend this style by making it the parent of a style that sets attributes for the tabs (like text color, indicator color, etc). This results in dark actionbar, light tabs, and light fragments. I can't find anything that will change the background of the tabs themselves. The only way I can change it is by changing the whole app to dark (using Theme.Sherlock). Here's my code so far: <style name="vpiTheme" parent="Theme.Sherlock.Light.DarkActionBar"> <item name="vpiTabPageIndicatorStyle">@style/CustomTabPageIndicator</item> </style> <style name="CustomTabPageIndicator" parent="Widget.TabPageIndicator"> <item name="android:textColor">#FF000000</item> <item name="android:paddingTop">6dp</item> <item name="android:paddingBottom">6dp</item> <item name="android:paddingLeft">16dip</item> <item name="android:paddingRight">16dip</item> <item name="android:maxLines">2</item> </style>

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• Dreamweaver not connecting RDC

  - by thomas

  I am trying to use Dreamweaver to Remote Desktop Connect into a computer where a website is hosted. Normal traffic to this server is routed to another domain, but when accessed by IP (it is my understanding) the traffic never hits any sort of nameserver request, and so stays there. This server is set up so that the only way I can access it is RDC. I can connect using an RDC program, but when I attempt to use Dreamweaver, I get a vague error. The desired action could not be completed because an unexpected client/server communication error occurred. I have Web URL as http://my.ip.number/directory And in the settings panel, I have Host name: my.ip.number Port: 3388 Host directory: C:\Program Files (x86)\directory/directory Username: user Password: ••••••• What could be preventing Dreamweaver form connecting? Thanks! SERVER DETAILS It is a virtual server Windows SERVER 2008 R2 Standard Service Pack 1

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• snmptrap and snmptt - authcommunity not found

  - by sabs6488

  I am trying to configure snmptt to translate the snmp traps received and handle them as passive checks in icinga monitoring server as described here . after doing the changes to the snmptrapd.conf . I am trying to restart the service and I see authcommunity : command not found, traphandle : command not found . my understanding is the authcommunity and traphandle are just configuration directives which will tell snmptrapd about the community string to use and the traphandle script to be called. It would be helpful if someone can help me understand better. Thanks, sabs

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• Javascript Graph Layout Engine

  - by GJK

  I'm looking for a Javascript library/engine that can do graph layouts. (And when I say layouts, I mean logically position vertices nicely.) The graphs I'm working with are all m-ary trees. M is usually no more than 5 or 6, but it can be greater in some cases. I do have something that I use now, Graphviz's node program, and it works perfectly. The problem is, when running a web app, I have to send a request to the server every time I want a layout. Preferably, I would like something written in Javascript that can be quickly run on the client side. All it needs to do is provide layout information (relative positioning and whatnot). I don't need it to draw to a canvas or use SVG or anything, all I'm interested in is the layout. Library use like jQuery or RaphaelJS is fine by me. I'll work with it. I'm just looking for something to speed things along a little. Also, I'd consider writing my own if I could find a nice description of an algorithm to do the layouts. But I really don't want to spend too much time. I have something that works now, so getting it on the client side is just a bonus, not a necessity.

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• Weblogic Class-Path Dependencies EAR

  - by user18287

  I am deploying an EAR in a WebLogic node with many jars defined in the bootstrap (startWeblogicServer.bat) class-path. The problem is that my ear and the bootstrap contain different versions of the same jars, not only that but certain jars contain extracted third party libraries which also differ in version from the WebLogic bootstrap jars causing all kinds of classpath errors. I know you can set preferred jars in the EAR application xml but, this can be very tedious to resolve with regards to jars which include extracted third party libraries in terms of understanding all the dependencies.. Is there a correct approach that i need to be taking here? Am i thinking about this in the wrong way? Any help would be greatly appreciated! So far prefer-web-inf-classes has been recommended but wont work because i'm not deploying a WAR, also prefer-application-packages is what we are currently using but still has the issue described above... Anymore advice out there?? Thanks!

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• Flash - can't access classes in another SWF

  - by Ashley Muller

  Hi, I'm trying to load a local SWF file and use the classes in that SWF (its a code only SWF, nothing in library). Here's the code that loads the library: var AD:ApplicationDomain = ApplicationDomain.currentDomain; var context:LoaderContext = new LoaderContext(false, AD); SA_gamecore_loader = new Loader(); SA_gamecore_loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onGameCoreLibraryDataComplete); SA_gamecore_loader.load(new URLRequest("GameCore.swf"), context); Here's the code that tries to instantiate a class from GameCore.swf: var test:Class = GetClassFromDefinition("MenuArt") as Class; var testInstance:Object = new test(); public function GetClassFromDefinition(theStr:String):Object { var theClass:Object; try { theClass = GameCoreLibraryData.applicationDomain.getDefinition(theStr); } catch(e:ReferenceError) { trace(e); return null; } return theClass; } And this is the message that's traced: ReferenceError: Error #1065: Variable MenuArt is not defined. The GameCore.swf is in the same location as the parent swf. I'm using Flash Develop if that helps. Anyone able to point out what I'm doing wrong?

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• How to set/keep directory permissions?

  - by Dylan

  I'm using CwRsync to connect from my Windows development machine to a linux webserver : rsync -avuz -e ./ssh --exclude=".svn" /cygdrive/c/xampp/htdocs/project123/ [email protected]:/home/user123/public_html This syncs my development project directory nicely and fast to the server. But after doing this, all directory properties are reset to the local user user123 only, so the website is not available anymore. I need to manually reset those properties. Why is this happening, and how to prevent it? PS. coming from a Windows environment I'm having a really hard time understanding rsync. I copied the above command from some examples... just need to get this one small thing working too...

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• SSL on Apache seems to significantly affect WebDAV performace

  - by takesides

  I'm using Apache 2.2 running on Windows Server 2008 R2 as a WebDAV server for clients to upload large media files (roughly 100-2000MB). I am finding that when I have SSL enabled (openSSL 0.9.8o) and use HTTPS for the uploads the throughput is around 13Mbps but when I disable it and just use HTTP I get around 80Mbps. I can't understand why this is happening as my understanding was that the heavy SSL work was done at the beginning of the connection. Does anyone have any idea why the performance is so drastically affected by enabling SSL? Cheers.

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• non-cached RSLs in Flex?

  - by SteMa

  I have a project that is for several customers, the only difference is in the DB, everything else looks the same, except for the main page's text. That is loaded from an external swf file. I created a library, compiled it as an swc, imported it and using it as an RSL. The problem is that if once I've opened the page, and afterwards update the rsl (because changes in the text are needed), than it's already cached by the browser (not the flashplayer's cache but we shouldn't discuss this please!) and the updated swf won't be loaded. If I use it as an external, the page won't even start up (the browser says it's loaded, but it's blank, not even the loading progess bar of flex appear) <local:MainPage includeIn="default" currentState="{MainPageState}" id="Page" width="100%" height="100%" /> this is the code on the main page, if I comment this out, than the whole thing loads, even with the use of the "external" link-type. If it helps, in the design view, I see the component, but I get a warning for the library: Design mode could not load MainPage.swc. It may be incompatible with this SDK, or invalid. (DesignAssetLoader.CompleteTimeout)

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• Problem using a COM interface as parameter

  - by Cesar

  I have the following problem: I have to projects Project1 and Project2. In Project1 I have an interface IMyInterface. In Project2 I have an interface IMyInterface2 with a method that receives a pointer to IMyInterface1. When I use import "Project1.idl"; in my Project2.idl, a #include "Project1.h" appears in Project2___i.h. But this file does not even exist!. What is the proper way to import an interface defined into other library into a idl file? I tried to replace the #include "Project1.h" by *#include "Project1_i.h"* or *#include "Project1_i.c"*, but it gave me a lot of errors. I also tried to use importlib("Project1.tlb") and define my interface IMyInterface2 within the library definition. But when I compile Project2PS project, an error is raised (something like dlldata.c is not generated if no interface is defined). I tried to create a dummy Project1.h. But when Project2___i.h is compiled, compiler cannot find MyInterface1. And if I include Project1___i.h I get a lot of errors again! Apparently, it is a simple issue, but I don't know how to solve it. I'm stuck with that!. By the way, I'm using VS2008 SP1. Thanks in advance.

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• lapply slower than for-loop when used for a BiomaRt query. Is that expected?

  - by ptocquin

  I would like to query a database using BiomaRt package. I have loci and want to retrieve some related information, let say description. I first try to use lapply but was surprise by the time needed for the task to be performed. I thus tried a more basic for-loop and get a faster result. Is that expected or is something wrong with my code or with my understanding of apply ? I read other posts dealing with *apply vs for-loop performance (Here, for example) and I was aware that improved performance should not be expected but I don't understand why performance here is actually lower. Here is a reproducible example. 1) Loading the library and selecting the database : library("biomaRt") athaliana <- useMart("plants_mart_14") athaliana <- useDataset("athaliana_eg_gene",mart=athaliana) 2) Querying the database : loci <- c("at1g01300", "at1g01800", "at1g01900", "at1g02335", "at1g02790", "at1g03220", "at1g03230", "at1g04040", "at1g04110", "at1g05240" ) I create a function for the use in lapply : foo <- function(loci) { getBM("description","tair_locus",loci,athaliana) } When I use this function on the first element : > system.time(foo(cwp_loci[1])) utilisateur système écoulé 0.020 0.004 1.599 When I use lapply to retrieve the data for all values : > system.time(lapply(loci, foo)) utilisateur système écoulé 0.220 0.000 16.376 I then created a new function, adding a for-loop : foo2 <- function(loci) { for (i in loci) { getBM("description","tair_locus",loci[i],athaliana) } } Here is the result : > system.time(foo2(loci)) utilisateur système écoulé 0.204 0.004 10.919 Of course, this will be applied to a big list of loci, so the best performing option is needed. I thank you for assistance. EDIT Following recommendation of @MartinMorgan Simply passing the vector loci to getBM greatly improves the query efficiency. Simpler is better. > system.time(lapply(loci, foo)) utilisateur système écoulé 0.236 0.024 110.512 > system.time(foo2(loci)) utilisateur système écoulé 0.208 0.040 116.099 > system.time(foo(loci)) utilisateur système écoulé 0.028 0.000 6.193

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