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  • summing functions handles in matlab

    - by user552231
    Hi I am trying to sum two function handles, but it doesn't work. for example: y1=@(x)(x*x); y2=@(x)(x*x+3*x); y3=y1+y2 The error I receive is "??? Undefined function or method 'plus' for input arguments of type 'function_handle'." This is just a small example, in reality I actually need to iteratively sum about 500 functions that are dependent on each other. EDIT The solution by Clement J. indeed works but I couldn't manage to generalize this into a loop and ran into a problem. I have the function s=@(x,y,z)((1-exp(-x*y)-z)*exp(-x*y)); And I have a vector v that contains 536 data points and another vector w that also contains 536 data points. My goal is to sum up s(v(i),y,w(i)) for i=1...536 Thus getting one function in the variable y which is the sum of 536 functions. The syntax I tried in order to do this is: sum=@(y)(s(v(1),y,z2(1))); for i=2:536 sum=@(y)(sum+s(v(i),y,z2(i))) end

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  • Battery drains even with app off screen, could it be Location Services doing it?

    - by John Jorsett
    I run my app, which uses GPS and Bluetooth, then hit the back button so it goes off screen. I verified via LogCat that the app's onDestroy was called. OnDestroy removes the location listeners and shuts down my app's Bluetooth service. I look at the phone 8 hours later and half the battery charge has been consumed, and my app was responsible according the phone's Battery Use screen. If I use the phone's Settings menu to Force Stop the app, this doesn't occur. So my question is: do I need to do something more than remove the listeners to stop Location Services from consuming power? That's the only thing I can think of that would be draining the battery to that degree when the app is supposedly dormant. Here's my onStart() where I turn on the location-related stuff and Bluetooth: @Override public void onStart() { super.onStart(); if(D_GEN) Log.d(TAG, "MainActivity onStart, adding location listeners"); // If BT is not on, request that it be enabled. // setupBluetooth() will then be called during onActivityResult if (!mBluetoothAdapter.isEnabled()) { Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableIntent, REQUEST_ENABLE_BT); // Otherwise, setup the Bluetooth session } else { if (mBluetoothService == null) setupBluetooth(); } // Define listeners that respond to location updates mLocationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, GPS_UPDATE_INTERVAL, 0, this); mLocationManager.addGpsStatusListener(this); mLocationManager.addNmeaListener(this); } And here's my onDestroy() where I remove them: public void onDestroy() { super.onDestroy(); if(D_GEN) Log.d(TAG, "MainActivity onDestroy, removing update listeners"); // Remove the location updates if(mLocationManager != null) { mLocationManager.removeUpdates(this); mLocationManager.removeGpsStatusListener(this); mLocationManager.removeNmeaListener(this); } if(D_GEN) Log.d(TAG, "MainActivity onDestroy, finished removing update listeners"); if(D_GEN) Log.d(TAG, "MainActivity onDestroy, stopping Bluetooth"); stopBluetooth(); if(D_GEN) Log.d(TAG, "MainActivity onDestroy finished"); }

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  • Using list() to extract a data.table inside of a function

    - by Nathan VanHoudnos
    I must admit that the data.table J syntax confuses me. I am attempting to use list() to extract a subset of a data.table as a data.table object as described in Section 1.4 of the data.table FAQ, but I can't get this behavior to work inside of a function. An example: require(data.table) ## Setup some test data set.seed(1) test.data <- data.table( X = rnorm(10), Y = rnorm(10), Z = rnorm(10) ) setkey(test.data, X) ## Notice that I can subset the data table easily with literal names test.data[, list(X,Y)] ## X Y ## 1: -0.8356286 -0.62124058 ## 2: -0.8204684 -0.04493361 ## 3: -0.6264538 1.51178117 ## 4: -0.3053884 0.59390132 ## 5: 0.1836433 0.38984324 ## 6: 0.3295078 1.12493092 ## 7: 0.4874291 -0.01619026 ## 8: 0.5757814 0.82122120 ## 9: 0.7383247 0.94383621 ## 10: 1.5952808 -2.21469989 I can even write a function that will return a column of the data.table as a vector when passed the name of a column as a character vector: get.a.vector <- function( my.dt, my.column ) { ## Step 1: Convert my.column to an expression column.exp <- parse(text=my.column) ## Step 2: Return the vector return( my.dt[, eval(column.exp)] ) } get.a.vector( test.data, 'X') ## [1] -0.8356286 -0.8204684 -0.6264538 -0.3053884 0.1836433 0.3295078 ## [7] 0.4874291 0.5757814 0.7383247 1.5952808 But I cannot pull a similar trick for list(). The inline comments are the output from the interactive browser() session. get.a.dt <- function( my.dt, my.column ) { ## Step 1: Convert my.column to an expression column.exp <- parse(text=my.column) ## Step 2: Enter the browser to play around browser() ## Step 3: Verity that a literal X works: my.dt[, list(X)] ## << not shown >> ## Step 4: Attempt to evaluate the parsed experssion my.dt[, list( eval(column.exp)] ## Error in `rownames<-`(`*tmp*`, value = paste(format(rn, right = TRUE), (from data.table.example.R@1032mCJ#7) : ## length of 'dimnames' [1] not equal to array extent return( my.dt[, list(eval(column.exp))] ) } get.a.dt( test.data, "X" ) What am I missing? Update: Due to some confusion as to why I would want to do this I wanted to clarify. My use case is when I need to access a data.table column when when I generate the name. Something like this: set.seed(2) test.data[, X.1 := rnorm(10)] which.column <- 'X' new.column <- paste(which.column, '.1', sep="") get.a.dt( test.data, new.column ) Hopefully that helps.

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  • C++ Constructor With Parameters Won't Initialize, Errors C2059 and C2228

    - by Some Girl
    I'm a C# programmer trying to muddle through C++ to create a Windows Forms Application. I have a Windows Form that makes use of a user-created class. Basically I'm trying to use a constructor that takes parameters, but my form won't let me initialize the object with parameter. Here's the code, hopefully somebody can explain the problem to me because I'm completely baffled... Here's my header file: BankAcct.h public ref class BankAcct { private: int money; public: BankAcct(); BankAcct(int); void Deposit(int); void GetBalance(int&); }; And my definition file: BankAcct.cpp #include "StdAfx.h" #include "BankAcct.h" BankAcct::BankAcct() { money = 0; } BankAcct::BankAcct(int startAmt) { money = startAmt; } void BankAcct::Deposit(int depAmt) { money += depAmt; } void BankAcct::GetBalance(int& balance) { balance = money; } And finally my main form. Won't copy the whole thing, of course, but I'm trying to declare the new bank account object, and start it with a balance of say $50. private: BankAcct myAccount(50); //does not work! WHY?? //private: //BankAcct myAccount; //works then in the form constructor my code is this: public: frmBank(void) { InitializeComponent(); int bal; myAccount.GetBalance(bal); lblBankBalance->Text += Convert::ToString(bal); } I've included the BankAcct.h file at the top of my frmBank.h, what else am I doing wrong here? It works great if I use the default constructor (the one that starts the bank balance at zero). I get the following error messages: error C2059: syntax error: 'constant' and error C2228: left of '.GetBalance' must have class/struct/union Thank you for any and all help on this one!!

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  • Calling a non-activeX DLL in a VB6 application in Vista/Win7

    - by user1490330
    I have a VB6 app that utilizes a non-activeX DLL (non-registering). It's declared via the classic Public Declare Function "Function Name" Lib "Library.DLL" syntax. On my dev machine (XP) it works fine but when I deploy to Vista or Win7 I'm constantly greeted with a Run Time Error 48 - File Not Found for the DLL in question. I have tried copying that DLL to every directory I can think of including every environment path on the test machine and the app path too. These are all 32-bit test environments so it's not a SysWow64 issue. Possibly throwing a wrench into the mix is the fact that the application in question is an Outlook COM Addin. I managed to install VB6 on Win7 and was able to run a tiny sample app that utilizes this DLL (outside of the Outlook process) so I know it works PROVIDED the DLL is located in App path. If I call App.Path from my DLL when I run it on the test environment it shows, to no surprise, my installation directory however the DLL is there. I tried turning off UAC. I tried making the App.Path directory permissions open to everyone, still no dice.

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  • C#: Non-constructed generics as properties (eg. List<T>)

    - by Dav
    The Problem It's something I came across a while back and was able to work around it somehow. But now it came back, feeding on my curiosity - and I'd love to have a definite answer. Basically, I have a generic dgv BaseGridView<T> : DataGridView where T : class. Constructed types based on the BaseGridView (such as InvoiceGridView : BaseGridView<Invoice>) are later used in the application to display different business objects using the shared functionality provided by BaseGridView (like virtual mode, buttons, etc.). It now became necessary to create a user control that references those constructed types to control some of the shared functionality (eg. filtering) from BaseGridView. I was therefore hoping to create a public property on the user control that would enable me to attach it to any BaseGridView in Designer/code: public BaseGridView<T> MyGridView { get; set; }. The trouble is, it doesn't work :-) When compiled, I get the following message: The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?) Solutions? I realise I could extract the shared functionality to an interface, mark BaseGridView as implementing that interface, and then refer to the created interface in my uesr control. But I'm curious if there exists some arcane C# command/syntax that would help me achieve what I want - without polluting my solution with an interface I don't really need :-)

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  • Why do I have to specify pure virtual functions in the declaration of a derived class in Visual C++?

    - by neuviemeporte
    Given the base class A and the derived class B: class A { public: virtual void f() = 0; }; class B : public A { public: void g(); }; void B::g() { cout << "Yay!"; } void B::f() { cout << "Argh!"; } I get errors saying that f() is not declared in B while trying do define void B::f(). Do I have to declare f() explicitly in B? I think that if the interface changes I shouldn't have to correct the declarations in every single class deriving from it. Is there no way for B to get all the virtual functions' declarations from A automatically? EDIT: I found an article that says the inheritance of pure virtual functions is dependent on the compiler: http://www.objectmentor.com/resources/articles/abcpvf.pdf I'm using VC++2008, wonder if there's an option for this.

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  • filling colors on a map - PHP

    - by jeremy
    I am trying to determine how to fill colors onto a map - such as the "Risk" board game map. I've done this before with HTML tables, by pulling an HTML color code from a SQL table and then just using it to fill the cell the color I want it. But for a non-square map, I'm not sure where to look. I have created a very simple two color map - its white with black borders. My desired result is having the 'regions' on the map shaded with a color, based on data in a sql table (just like the "fill" button in Paint). This looks like what I need: http://php.net/manual/en/function.imagefilltoborder.php and now.. how to define the borders... At the moment I have tried nothing, because the question was: how do I have PHP fill parts of an image? I have tried making an image in Paint, and then scratching my head wondering how to fill parts of it. Having stumbled upon a link, let me focus this a bit more: It appears that with imagefilltoborder that I can put an image on my server, perhaps one that looks like a black and white version of the RISK map - black borders and white everything else. Some questions: Is it correct that the 'border' variable should use the color of my border (whatever value black is) so that the code can "see" where the border is? Is it correct that I'll just need to figure out X,Y coords to begin the fill? Does this work if I have 10 different spots to fill on the map? Can I use varying colors from code or pulled from SQL to assign different colors to those 10 spots, and use 10 different X,Y coords to get them all?

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  • How can I automatically highlight a specific character in link text using JQuery + CSS?

    - by Chris McCall
    I'm adding hotkeys to a web application in order to enable keyboard shortcuts for our CSRs to use, to reduce injury and increase calls-per-hour. I'm using an ASP.net UserControl to inject javascript into the page and it's working great. I want the control to "just work", so that when hotkeys are assigned, using a declarative syntax, if the hotkeyed letter exists in the link text, it will be highlighted automatically, so the developer doesn't have to do anything, and also to maintain consistency in visual cues. Here's the code to assign hotkeys, if it matters: <uc:HotKeysControl ID="theHotkeys" runat="server" Visible="true"> <uc:HotKey ControlName="AccStatus$btnInvoiceEverBill" KeyCode="ctrl+v" /> <uc:HotKey ControlName="AccStatus$btnRefund" KeyCode="ctrl+u" /> <uc:HotKey ControlName="thirdControl" KeyCode="ctrl+p" /> </uc:HotKeysControl> I want something like: <a href="whatever" name="thirdControl">Make a <span class=hotkey">P</span>ayment</a> ...but I'm not married to the idea of injecting a <span/> in there if there's a better way. How can I do this in CSS or JQuery? Is there a way to pass in a letter to a CSS style and have it change the color of the text displayed? Should I generate javascript to highlight the text when the page loads? What would/did you do in this situation?

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  • sum of square of each elements in the vector using for_each

    - by pierr
    Hi, As the function accepted by for_each take only one parameter (the element of the vector), I have to define a static int sum = 0 somewhere so that It can be accessed after calling the for_each . I think this is awkward. Any better way to do this (still use for_each) ? #include <algorithm> #include <vector> #include <iostream> using namespace std; static int sum = 0; void add_f(int i ) { sum += i * i; } void test_using_for_each() { int arr[] = {1,2,3,4}; vector<int> a (arr ,arr + sizeof(arr)/sizeof(arr[0])); for_each( a.begin(),a.end(), add_f); cout << "sum of the square of the element is " << sum << endl; } In Ruby, We can do it this way: sum = 0 [1,2,3,4].each { |i| sum += i*i} #local variable can be used in the callback function puts sum #=> 30 Would you please show more examples how for_each is typically used in practical programming (not just print out each element)? Is it possible use for_each simulate 'programming pattern' like map and inject in Ruby (or map /fold in Haskell). #map in ruby >> [1,2,3,4].map {|i| i*i} => [1, 4, 9, 16] #inject in ruby [1, 4, 9, 16].inject(0) {|aac ,i| aac +=i} #=> 30 EDIT: Thank you all. I have learned so much from your replies. We have so many ways to do the same single thing in C++ , which makes it a little bit difficult to learn. But it's interesting :)

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  • Generic Constraints And Type Parameters Mess

    - by Dummy01
    Hi everyone, I have the following base abstract class defined as: public abstract class BaseObject<T> : IComparable, IComparable<T>, IEquatable<T> {} I also have an interface defined as: public interface ICode<T> where T : struct { T Code { get; } } Now I want to derive a class that is inherited from BaseObject<T> and includes interface ICode<T>. I tried to define it like that: public class DerivedObject<T, U> : BaseObject<T>, ICode<U> where T : DerivedObject<T, U> where U : struct { public DerivedObject(U code) { Code = code; } // From BaseObject protected override int InstanceCompareTo(T obj) { return Code.CompareTo(obj.Code); } // From BaseObject protected override bool InstanceEquals(T obj) { return Code.Equals(obj.Code); } // From ICode U _Code; public U Code { get { return _Code; } protected set { _Code = value; } } } The only error that comes from the compiler is for Code.CompareTo(obj.Code) with the message: 'U' does not contain a definition for 'CompareTo' and no extension method 'CompareTo' accepting a first argument of type 'U' could be found. But U is a value type and should know CompareTo. Have you any idea what I am doing wrong, or if I do all wrong? My final aim is to derive classes such these: public class Account : DerivedObject<Account, int> public class ItemGroup : DerivedObject<ItemGroup, string> Big Thanks In Advance!

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  • Adding Variables to JavaScript in Joomla

    - by Vikram
    Hello friends! This is the script I am using to display an accordion in my Joomla site: <?php defined('JPATH_BASE') or die(); gantry_import('core.gantryfeature'); class GantryFeatureAccordion extends GantryFeature { var $_feature_name = 'accordion'; function init() { global $gantry; if ($this->get('enabled')) { $gantry->addScript('accordion.js'); $gantry->addInlineScript($this->_accordion()); } } function render($position="") { ob_start(); ?> <div id="accordion"> <dl> <?php foreach (glob("templates/rt_gantry_j15/features/accordion/*.php") as $filename) {include($filename);} ?> </dl> </div> <?php return ob_get_clean(); } function _accordion() { global $gantry; $js = " jQuery.noConflict(); (function($){ $(document).ready(function () { $('#accordion').easyAccordion({ slideNum: true, autoStart: true, slideInterval: 4000 }); }); })(jQuery); "; return $js; } } I want to call these three values in the templateDetails.XML file as a user input. slideNum: true, autoStart: true, slideInterval: 4000 Like this in the templateDetails.xml file: <param name="accordion" type="chain" label="ACCORDION" description="ACCORDION_DESC"> <param name="slideNum" type="text" default="true" label="Offset Y" class="text-short" /> <param name="autoStart" type="text" default="true" label="Offset Y" class="text-short" /> <param name="autoStart" type="text" default="4000" label="Offset Y" class="text-short" /> </param> How can I do so? What will be the exact syntax for the same. I am very new to programming ans specially to JavaScript. Kindly help.

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  • Move to php in windows? Concern, hints, "please don't do!"?

    - by Daniel
    I am considering to move frome Microsoft languages to PHP (just for web dev) which has quite an interesting syntax, a perlish look (but a wider programmer base) and it allows me to reuse the web without reinventing it. I have some concerns too. I would be more than happy to gather some wisdom from stackoverflow community, (challenge to my opinions warmly welcome). Here are my doubts. Efficiency. Cgi are slow, what I am supposed to use? Fastcgi? Or what else? Efficiency + stability. Is PHP on windows really stable and a good choice in terms of performances? Database. I use very often MSSQL (I regret, i like it). Could I widely and efficiently interface PHP with MSSQL (using smartly stored pro, for example). XSLT + XML performance. I work quite a lot with XML and XSLT and I really find the MS xml parser a great software component. Are parser used in PHP fast, reliable and efficient (I am interested mainly in DOM, not SAX)? Objects. Is the PHP object programming model valid end efficient? 6 Regex. How efficient is PHP processing regexp? Many thanks for your advices.

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  • Symfony generating database from model

    - by Sergej Jevsejev
    Hello, I am having troubles generating a simple database form model. I am using: Doctrine on Symfony 1.4.4 MySQL Workbench 5.2.16 with Doctrine Export 0.4.2dev So my ERL Model is: http://img708.imageshack.us/img708/1716/tmg.png Genereted YAML file: --- detect_relations: true options: collate: utf8_unicode_ci charset: utf8 type: InnoDB Course: columns: id: type: integer(4) primary: true notnull: true autoincrement: true name: type: string(255) notnull: true keywords: type: string(255) notnull: true summary: type: clob(65535) notnull: true Lecture: columns: id: type: integer(4) primary: true notnull: true autoincrement: true course_id: type: integer(4) primary: true notnull: true name: type: string(255) notnull: true description: type: string(255) notnull: true url: type: string(255) relations: Course: class: Course local: course_id foreign: id foreignAlias: Lectures foreignType: many owningSide: true User: columns: id: type: integer(4) primary: true unique: true notnull: true autoincrement: true firstName: type: string(255) notnull: true lastName: type: string(255) notnull: true email: type: string(255) unique: true notnull: true designation: type: string(1024) personalHeadline: type: string(1024) shortBio: type: clob(65535) UserCourse: tableName: user_has_course columns: user_id: type: integer(4) primary: true notnull: true course_id: type: integer(4) primary: true notnull: true relations: User: class: User local: user_id foreign: id foreignAlias: UserCourses foreignType: many owningSide: true Course: class: Course local: course_id foreign: id foreignAlias: UserCourses foreignType: many owningSide: true And no matter what I try this error occurs after: symfony doctrine:build --all --no-confirmation SQLSTATE[42000]: Syntax error or access violation: 1072 Key column 'user_userid' doesn't exist in table. Failing Query: "ALTER TABLE user_has_course ADD CONSTRAINT user_has_course_user_userid_user_id FOREIGN KEY (user_userid) REFERENCES user(id)". Failing Query: ALTER TABLE user_has_course ADD CONSTRAINT user_has_cou rse_user_userid_user_id FOREIGN KEY (user_userid) REFERENCES user(id) Currently I am studying Symfony, and stuck with this error. Please help.

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  • How do I insert null fields with Perl's DBD::Pg?

    - by User1
    I have a Perl script inserting data into Postgres according to a pipe delimited text file. Sometimes, a field is null (as expected). However, Perl makes this field into an empty string and the Postgres insert statement fails. Here's a snippet of code: use DBI; #Connect to the database. $dbh=DBI-connect('dbi:Pg:dbname=mydb','mydb','mydb',{AutoCommit=1,RaiseError=1,PrintError=1}); #Prepare an insert. $sth=$dbh-prepare("INSERT INTO mytable (field0,field1) SELECT ?,?"); while (<){ #Remove the whitespace chomp; #Parse the fields. @field=split(/\|/,$_); print "$_\n"; #Do the insert. $sth-execute($field[0],$field[1]); } And if the input is: a|1 b| c|3 EDIT: Use this input instead. a|1|x b||x c|3|x It will fail at b|. DBD::Pg::st execute failed: ERROR: invalid input syntax for integer: "" I just want it to insert a null on field1 instead. Any ideas? EDIT: I simplified the input at the last minute. The old input actually made it work for some reason. So now I changed the input to something that will make the program fail. Also note that field1 is a nullable integer datatype.

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  • error catching exception while System.out.print

    - by user1702633
    I have 2 classes, one that implements a double lookup( int i); and one where I use that lookup(int i) in solving a question, or in this case printing the lookup values. This case is for an array. So I read the exception documentation or google/textbook and come with the following code: public double lookup(int i) throws Exception { if( i > numItems) throw new Exception("out of bounds"); return items[i]; } and take it over to my class and try to print my set, where set is a name of the object type I define in the class above. public void print() { for (int i = 0; i < set.size() - 1; i++) { System.out.print(set.lookup(i) + ","); } System.out.print(set.lookup(set.size())); } I'm using two print()'s to avoid the last "," in the print, but am getting an unhandled exception Exception (my exception's name was Exception) I think I have to catch my exception in my print() but cannot find the correct formatting online. Do I have to write catch exception Exception? because that gives me a syntax error saying invalid type on catch. Sources like http://docs.oracle.com/javase/tutorial/essential/exceptions/ are of little help to me, I'm can't seem to grasp what the text is telling me. I'm also having trouble finding sources with multiple examples where I can actually understand the coding in the examples. so could anybody give me a source/example for the above catch phrase and perhaps a decent source of examples for new Java programmers? my book is horrendous and I cannot seem to find an understandable example for the above catch phrase online.

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  • Update list dom only if list displayed

    - by Nikolaj Borisik
    Sometimes we use one store for few views(list, carousel,dataviews) and when we refresh(load, filter) store data, dom of all view that use this store will be rebuild, but some views is not displayed in this time, and may be will not show with these data. How we can refresh list dom only if it displayed, not every time when it store refresh? Issue examle Ext.define("Test.view.Main", { extend: 'Ext.tab.Panel', config: { tabBarPosition: 'bottom', items: [ ] }, constructor : function(){ this.callParent(arguments); var store = Ext.create('Ext.data.Store',{ data :[ {title : 'One'}, {title : 'Two'}, {title : 'Three'} ] }), firstList = Ext.create('Ext.List',{ title : 'tab1', store : store, itemTpl : '{title}', onItemDisclosure : function(){ store.add({title : 'Four'}); } }), secondList = Ext.create('Ext.List',{ title : 'tab2' , store : store, itemTpl : '{title}' }), thirdList = Ext.create('Ext.List',{ title : 'tab3', store : store, itemTpl : '{title}' }); this.add([ firstList, secondList, thirdList ]) ; } }); When tap on item in the first list, in store will be added new item. And dom of all list will be change although second and third list not displayed I see one option. Create one main store and create separate stores for each views. And when view show fill it store from Main store. But it look not good. Any other ideas?

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  • Can Haskell's monads be thought of as using and returning a hidden state parameter?

    - by AJM
    I don't understand the exact algebra and theory behind Haskell's monads. However, when I think about functional programming in general I get the impression that state would be modelled by taking an initial state and generating a copy of it to represent the next state. This is like when one list is appended to another; neither list gets modified, but a third list is created and returned. Is it therefore valid to think of monadic operations as implicitly taking an initial state object as a parameter and implicitly returning a final state object? These state objects would be hidden so that the programmer doesn't have to worry about them and to control how they gets accessed. So, the programmer would not try to copy the object representing the IO stream as it was ten minutes ago. In other words, if we have this code: main = do putStrLn "Enter your name:" name <- getLine putStrLn ( "Hello " ++ name ) ...is it OK to think of the IO monad and the "do" syntax as representing this style of code? putStrLn :: IOState -> String -> IOState getLine :: IOState -> (IOState, String) main :: IOState -> IOState -- main returns an IOState we can call "state3" main state0 = putStrLn state2 ("Hello " ++ name) where (state2, name) = getLine state1 state1 = putStrLn state0 "Enter your name:"

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  • parsing python to csv

    - by user185955
    I'm trying to download some game stats to do some analysis, only problem is each season the data their isn't 100% consistent. I grab the json file from the site, then wish to save it to a csv with the first line in the csv containing the heading for that column, so the heading would be essentially the key from the python data type. #!/usr/bin/env python import requests import json import csv base_url = 'http://www.afl.com.au/api/cfs/afl/' token_url = base_url + 'WMCTok' player_url = base_url + 'matchItems/round' def printPretty(data): print(json.dumps(data, sort_keys=True, indent=2, separators=(',', ': '))) session = requests.Session() # session makes it simple to use the token across the requests token = session.post(token_url).json()['token'] # get the token session.headers.update({'X-media-mis-token': token}) # set the token Season = 2014 Roundno = 4 if Roundno<10: strRoundno = '0'+str(Roundno) else: strRoundno = str(Roundno) # get some data (could easily be a for loop, might want to put in a delay using Sleep so that you don't get IP blocked) data = session.get(player_url + '/CD_R'+str(Season)+'014'+strRoundno) # print everything printPretty(data.json()) with open('stats_game_test.csv', 'w', newline='') as csvfile: spamwriter = csv.writer(csvfile, delimiter="'",quotechar='|', quoting=csv.QUOTE_ALL) for profile in data.json()['items']: spamwriter.writerow(['%s' %(profile)]) #for key in data.json().keys(): # print("key: %s , value: %s" % (key, data.json()[key])) The above code grabs the json and writes it to a csv, but it puts the key in each individual cell next to the value (eg 'venueId': 'CD_V190'), the key needs to be just across the first row as a heading. It gives me a csv file with data in the cells like this Column A B 'tempInCelsius': 17.0 'totalScore': 32 'tempInCelsius': 16.0 'totalScore': 28 What I want is the data like this tempInCelsius totalScore 17 32 16 28 As I mentioned up the top, the data isn't always consistent so if I define what fields to grab with spamwriter.writerow([profile['tempInCelsius'], profile['totalScore']]) then it will error out on certain data grabs. This is why I'm now trying the above method so it just grabs everything regardless of what data is there.

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  • Design by contracts and constructors

    - by devoured elysium
    I am implementing my own ArrayList for school purposes, but to spice up things a bit I'm trying to use C# 4.0 Code Contracts. All was fine until I needed to add Contracts to the constructors. Should I add Contract.Ensures() in the empty parameter constructor? public ArrayList(int capacity) { Contract.Requires(capacity > 0); Contract.Ensures(Size == capacity); _array = new T[capacity]; } public ArrayList() : this(32) { Contract.Ensures(Size == 32); } I'd say yes, each method should have a well defined contract. On the other hand, why put it if it's just delegating work to the "main" constructor? Logicwise, I wouldn't need to. The only point I see where it'd be useful to explicitly define the contract in both constructors is if in the future we have Intelisense support for contracts. Would that happen, it'd be useful to be explicit about which contracts each method has, as that'd appear in Intelisense. Also, are there any books around that go a bit deeper on the principles and usage of Design by Contracts? One thing is having knowledge of the syntax of how to use Contracts in a language (C#, in this case), other is knowing how and when to use it. I read several tutorials and Jon Skeet's C# in Depth article about it, but I'd like to go a bit deeper if possible. Thanks

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  • How can I concisely copy multiple SQL rows, with minor modifications?

    - by Steve Jessop
    I'm copying a subset of some data, so that the copy will be independently modifiable in future. One of my SQL statements looks something like this (I've changed table and column names): INSERT Product( ProductRangeID, Name, Weight, Price, Color, And, So, On ) SELECT @newrangeid AS ProductRangeID, Name, Weight, Price, Color, And, So, On FROM Product WHERE ProductRangeID = @oldrangeid and Color = 'Blue' That is, we're launching a new product range which initially just consists of all the blue items in some specified current range, under new SKUs. In future we may change the "blue-range" versions of the products independently of the old ones. I'm pretty new at SQL: is there something clever I should do to avoid listing all those columns, or at least avoid listing them twice? I can live with the current code, but I'd rather not have to come back and modify it if new columns are added to Product. In its current form it would just silently fail to copy the new column if I forget to do that, which should show up in testing but isn't great. I am copying every column except for the ProductRangeID (which I modify), the ProductID (incrementing primary key) and two DateCreated and timestamp columns (which take their auto-generated values for the new row). Btw, I suspect I should probably have a separate join table between ProductID and ProductRangeID. I didn't define the tables. This is in a T-SQL stored procedure on SQL Server 2008, if that makes any difference.

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  • Help with this compile error

    - by Scott
    I just picked up an old project and I'm not sure what the following error could mean. g++ -o BufferedReader.o -c -g -Wall -std=c++0x -I/usr/include/xmms2 -Ijsoncpp/include/json/ -fopenmp -I/usr/include/ImageMagick -I/usr/include/xmms2 -I/usr/include/libvisual-0.4 -D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL -DQT_CORE_LIB -DQT_GUI_LIB -DQT_SCRIPT_LIB -DQT_SHARED -I/usr/include/QtCore -I/usr/include/QtGui -I/usr/include/QtScript BufferedReader.cpp In file included from BufferedReader.cpp:23: /usr/include/string.h:36:42: error: missing binary operator before token "(" In file included from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/cwchar:47, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/bits/postypes.h:42, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/iosfwd:42, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/ios:39, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/istream:40, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/sstream:39, from BufferedReader.cpp:24: At line 24 of BufferedReader.cpp is #include <string.h>. I've tried it with just <string> but get the same thing. Any clue? Here's the snippet of code from string.h /* Tell the caller that we provide correct C++ prototypes. */ #if defined __cplusplus && __GNUC_PREREQ (4, 4) //line 36 # define __CORRECT_ISO_CPP_STRING_H_PROTO #endif Does that mean __GNUC_PREREQ isn't defined?

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  • Building a survey to put in a WordPress website using Python/Django

    - by chiurox
    So I've been given a task to build a survey to get data regarding time slot preferences of prospective students for a particular course. I know there are really quick solutions to this like Google Forms, SurveyMonkey, but since it's not unusually hard, I want to implement the survey myself in a totally new language as an opportunity to get started with it and also be able to customize and provide dynamic info to the users who are voting. Although I have done some stuff in PHP, C++, javascript, etc, I'm pretty new to Python+Django framework but it's something I've been meaning to get into since a long time ago. Initially, what I want is to make a grid with the days of the week as columns and time-durations as rows. In each cell I want to provide users a way to choose how strong (high/medium/low) their preference for this particular day+time is. I also want to show how many "votes" have already been cast for this particular preference because this will influence a lot in their decisions and as a result make this process easier when we are going to define the classes. I'll probably store the data in MySQL. Could anyone point me to some really good Python+Django tutorials for my particular purpose? Does anyone think I'm wasting my time with this trivial task by choosing new tools and that I should just use something I already know (like PHP) or a free service or plugin for Wordpress? Thanks!

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  • How do C++ compilers actually pass reference parameters?

    - by T.E.D.
    This question came about as a result of some mixed-langauge programming. I had a Fortran routine I wanted to call from C++ code. Fortran passes all its parameters by reference (unless you tell it otherwise). So I thought I'd be clever (bad start right there) in my C++ code and define the Fortran routine something like this: extern "C" void FORTRAN_ROUTINE (unsigned & flag); This code worked for a while but (of course right when I needed to leave) suddenly started blowing up on a return call. Clear indication of a munged call stack. Another engineer came behind me and fixed the problem, declaring that the routine had to be deinfed in C++ as extern "C" void FORTRAN_ROUTINE (unsigned * flag); I'd accept that except for two things. One is that it seems rather counter-intuitive for the compiler to not pass reference parameters by reference, and I can find no documentation anywhere that says that. The other is that he changed a whole raft of other code in there at the same time, so it theoretically could have been another change that fixed whatever the issue was. So the question is, how does C++ actually pass reference parameters? Is it perhaps free to do copy-in, copy-out for small values or something? In other words, are reference parameters utterly useless in mixed-language programming? I'd like to know so I don't make this same code-killing mistake ever again.

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  • LINQ-to-SQL - Join, Count

    - by ile
    I have following query: var result = ( from role in db.Roles join user in db.Users on role.RoleID equals user.RoleID where user.CreatedByUserID == userID orderby user.FirstName ascending select new UserViewModel { UserID = user.UserID, PhotoID = user.PhotoID.ToString(), FirstName = user.FirstName, LastName = user.LastName, FullName = user.FirstName + " " + user.LastName, Email = user.Email, PhoneNumber = user.Phone, AccessLevel = role.Name }); Now, I need to modify this query... Other table I have is table Deals. I would like to count how many deals user created last month and last year. I tried something like this: var result = ( from role in db.Roles join user in db.Users on role.RoleID equals user.RoleID //join dealsYear in db.Deals on date.Year equals dealsYear.DateCreated.Year join dealsYear in ( from deal in db.Deals group deal by deal.DateCreated into d select new { DateCreated = d.Key, dealsCount = d.Count() } ) on date.Year equals dealsYear.DateCreated.Year into dYear join dealsMonth in ( from deal in db.Deals group deal by deal.DateCreated into d select new { DateCreated = d.Key, dealsCount = d.Count() } ) on date.Month equals dealsMonth.DateCreated.Month into dMonth where user.CreatedByUserID == userID orderby user.FirstName ascending select new UserViewModel { UserID = user.UserID, PhotoID = user.PhotoID.ToString(), FirstName = user.FirstName, LastName = user.LastName, FullName = user.FirstName + " " + user.LastName, Email = user.Email, PhoneNumber = user.Phone, AccessLevel = role.Name, DealsThisYear = dYear, DealsThisMonth = dMonth }); but here is even syntax not correct. Any idea? Btw, is there any good book of LINQ to SQL with examples?

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