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• Forking in PHP on Windows

  - by Doug Kavendek

  We are running PHP on a Windows server (a source of many problems indeed, but migrating is not an option currently). There are a few points where a user-initiated action will need to kick off a few things that take a while and about which the user doesn't need to know if they succeed or fail, such as sending off an email or making sure some third-party accounts are updated. If I could just fork with pcntl_fork(), this would be very simple, but the PCNTL functions are not available in Windows. It seems the closest I can get is to do something of this nature: exec( 'php-cgi.exe somescript.php' ); However, this would be far more complicated. The actions I need to kick off rely on a lot of context that already will exist in the running process; to use the above example, I'd need to figure out the essential data and supply it to the new script in some way. If I could fork, it'd just be a matter of letting the parent process return early, leaving the child to work on a few more things. I've found a few people talking about their own work in getting various PCNTL functions compiled on Windows, but none seemed to have anything available (broken links, etc). Despite this question having practically the same name as mine, it seems the problem was more execution timeout than needing to fork. So, is my best option to just refactor a bit to deal with calling php-cgi, or are there other options? Edit: It seems exec() won't work for this, at least not without me figuring some other aspect of it, as it waits until the call returns. I figured I could use START, sort of like exec( 'start php-cgi.exe somescript.php' );, but it still waits until the other script finishes.

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• Error doing an MSBuild on a CLR Storedprocedure project on Build Server

  - by CraftyFella

  Hi, When building a CLR Storedprocedure Project using MSBuild on our build server (Team City) we're getting the following error: error MSB4019: The imported project "C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\SqlServer.targets" was not found. Confirm that the path in the declaration is correct, and that the file exists on disk I've checked to see if the file exists on disk and sure enough it doesn't. I've checked on my own machine and it does exist. I don't really want to start copying over files manually to the build server. Here's the line from the csproj file which is being imported to the proj file: <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" /> <Import Project="$(MSBuildToolsPath)\SqlServer.targets" /> Here's the line from the proj file which is begin run by our Team City Server: <Import Project="..\$(ProjectName).csproj"/> My question is really: Where does this file comes from? Is it part of the Visual Studio install for example.. Or is there some re-distribution package somewhere to allow me to compile this project on our build server? Thanks BTW.. if i just copy the file onto the Build server it does actually work. Dave

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• IoC & Interfaces Best Practices

  - by n8wrl

  I'm experimenting with IoC on my way to TDD by fiddling with an existing project. In a nutshell, my question is this: what are the best practices around IoC when public and non-public methods are of interest? There are two classes: public abstract class ThisThingBase { public virtual void Method1() {} public virtual void Method2() {} public ThatThing GetThat() { return new ThatThing(this); } internal virtual void Method3() {} internal virtual void Method4() {} } public class Thathing { public ThatThing(ThisThingBase thing) { m_thing = thing; } ... } ThatThing does some stuff using its ThisThingBase reference to call methods that are often overloaded by descendents of ThisThingBase. Method1 and Method2 are public. Method3 and Method4 are internal and only used by ThatThings. I would like to test ThatThing without ThisThing and vice-versa. Studying up on IoC my first thought was that I should define an IThing interface, implement it by ThisThingBase and pass it to the ThatThing constructor. IThing would be the public interface clients could call but it doesn't include Method3 or Method4 that ThatThing also needs. Should I define a 2nd interface - IThingInternal maybe - for those two methods and pass BOTH interfaces to ThatThing?

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• Hiring a programmer: looking for the "right attitude"

  - by Totophil

  It's actually two questions in one: What is the right attitude for a programmer? How do you (or would you) look for one when interviewing or during hiring process? Please note this question is not about personality or traits of a candidate, it is about their attitude towards what they do for living. This is also not about reverse of programmers pet peeves. The question has been made community wiki, since I am interested in a good answer rather than reputation. I disagree that the question is purely subjective and just a matter of opinion: clearly some attitudes make a better programmer than others. Consecutively, there might quite possibly exist an attitude that is common to the most of the better programmers. Update: After some deliberation I came up with the following attitude measurement scales: identifies themselves with the job ? fully detached perceives code as a collection of concepts ? sees code as a sequence of steps thinks of creating software as an art ? takes 100% rational approach to design and development Answers that include some sort of a comment on the appropriateness of these scales are greatly appreciated. Definition of "attitude": a complex mental state involving beliefs and feelings and values and dispositions to act in certain ways; "he had the attitude that work was fun" The question came as a result of some reflection on the top voted answer to "How do you ensure code quality?" here on Stack Overflow.

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• When and how should independent hierarchies be used in clojure?

  - by Rob Lachlan

  Clojure's system for creating an ad hoc hierarchy of keywords is familiar to most people who have spent a bit of time with the language. For example, most demos and presentations of the language include examples such as (derive ::child ::parent) and they go on to show how this can be used for multi-method dispatch. In all of the slides and presentations that I've seen, they use the global hierarchy. But it is possible to put keyword relationships in independent hierarchies, by using (derive h ::child ::parent), where h is created by (make-hierarchy). Some questions, therefore: Are there any guidelines on when this is useful or necessary? Are there any functions for manipulating hierarchies? Merging is particularly useful, so I do this: (defn merge-h [& hierarchies] (apply merge-with (cons #(merge-with clojure.set/union %1 %2) hierarchies)) But I was wondering if such functions already exist somewhere. EDIT: Changed "custom" hierarchy to "independent" hierarchy, since that term better describes this animal. Also, I've done some research and included my own answer below. Further comments are welcome.

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• WPF: How do I get a reference to a styled window control in code behind?

  - by Brad

  I have a window defined with a style: <Window x:Class="winBorderless" x:Name="winBorderless" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Local="clr-namespace:WindowStyle" Style="{StaticResource Window_Cartesia}" WindowStartupLocation="CenterScreen" BorderThickness="1" BorderBrush="#FF9CAAC1" Margin="5" Title="[Document Title]"> and the style defined in an application level dictionary: <Style x:Key="Window_Cartesia" TargetType="{x:Type Window}"> <Setter Property="WindowStyle" Value="None"/> <Setter Property="AllowsTransparency" Value="True"/> <Setter Property="Background" Value="Transparent"/> <EventSetter Event="Loaded" Handler="Loaded"/> <EventSetter Event="PreviewKeyDown" Handler="Preview_KeyDown"/> <EventSetter Event="MouseMove" Handler="FullScreen_MouseMove"/> <Setter Property="Template"> In code behind I have a reference to the Window instance set: Win = DirectCast(sender, winBorderless) This allows access to the window properties as the EventSetters pass references to the various controls. However, it doesn't provide for access to the controls defined in the style through the window reference as they don't exist there. So, what is the best way to reference a control through code behind that is defined in the style. I'd prefer not to iterate the trees to find them but ya gotta do....

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• Why Java language does not offer a way to declare getters and setters of a given "field" through ann

  - by zim2001

  I actually happily design and develop JEE Applications for quite 9 years, but I realized recently that as time goes by, I feel more and more fed up of dragging all these ugly bean classes with their bunch of getters and setters. Considering a basic bean like this : public class MyBean { // needs getter AND setter private int myField1; // needs only a getter, no setter private int myField2; // needs only a setter, no getter private int myField3; /** * Get the field1 * @return the field1 */ public int getField1() { return myField1; } /** * Set the field1 * @param value the value */ public void setField1(int value) { myField1 = value; } /** * Get the field2 * @return the field2 */ public int getField2() { return myField2; } /** * Set the field3 * @param value the value */ public void setField3(int value) { myField3 = value; } } I'm dreaming of something like this : public class MyBean { @inout(public,public) private int myField1; @out(public) private int myField2; @in(public) private int myField3; } No more stupid javadoc, just tell the important thing... It would still be possible to mix annotation and written down getters or setters, to cover cases when it should do non-trivial sets and gets. In other words, annotation would auto-generate the getter / setter code piece except when a literate one is provided. Moreover, I'm also dreaming of replacing things like that : MyBean b = new MyBean(); int v = b.getField1(); b.setField3(v+1); by such : MyBean b = new MyBean(); int v = b.field1; b.field3 = v+1; In fact, writing "b.field1" on the right side of an expression would be semantically identical to write "b.getField1()", I mean as if it has been replaced by some kind of a preprocessor. It's just an idea but I'm wondering if I'm alone on that topic, and also if it has major flaws. I'm aware that this question doesn't exactly meet the SO credo (we prefer questions that can be answered, not just discussed) so I flag it community wiki...

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• DataGridComboBoxColumn was not found

  - by Budda

  The System.Windows.Controls.Data.DataGrid is used in my Silverlight application, but on attempt to add 'DataGridComboBoxColumn' column to the grid the following error messages are obtained: Error 1 The tag 'DataGridComboBoxColumn' does not exist in XML namespace 'clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data'. C:\Project\Budda\VFMElita\VfmElitaView\Pages\SquadView.xaml 140 22 VfmElitaView Error 2 The type 'data:DataGridComboBoxColumn' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built. C:\Project\Budda\VFMElita\VfmElitaView\Pages\SquadView.xaml 142 22 VfmElitaView Here is my "header" of the xaml-file: Here is grid: <StackPanel Grid.Row="1" Grid.Column="0" Grid.RowSpan="2"> <TextBlock Text="????"/> <data:DataGrid AutoGenerateColumns="False" ItemsSource="{Binding FieldPlayers}"> <data:DataGrid.Columns> <!--<data:DataGridTemplateColumn Header="#"> <data:DataGridTemplateColumn.CellTemplate> <DataTemplate> <TextBlock Margin="4" Loaded="TextBlock_Loaded"/> </DataTemplate> </data:DataGridTemplateColumn.CellTemplate> </data:DataGridTemplateColumn>--> <data:DataGridTextColumn Header="?" Binding="{Binding Number}"/> <data:DataGridComboBoxColumn> - that doesn't work </data:DataGridComboBoxColumn> </data:DataGrid.Columns> </data:DataGrid> </StackPanel> What is required to get 'DataGridComboBoxColumn' workable? Any help is welcome. Thanks.

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• Attributes of attributevalue element in SAML 2 Attribute Statement

  - by AJ

  I am building a web service that receives a SAML attribute query and responds with an attribute statement. I know I can return one or multiple values of a SAML attribute. I have some values that are dependent on the other attribute values. I need to show that relationship. Let us say, the query is for the Subject Dave and the return values are his company and job title. Dave can work at multiple companies with job title at each company. I have two options of sending this data back: Send this as a complextype by defining an attribute organization and return xml within that attribute. <saml:Attribute name="company"> <saml:AttributeValue> <company name="company1" jobtitle="CIO"/> <company name="company2" jobtitle="VP"/> </saml:AttributeValue> Try to send multiple values of attributes somehow sending a reference in attributevalue element. <saml:Attribute name="company"> <attributeValue>company1</attributeValue> <attributeValue>company2</attributeValue> </saml:Attribute> <saml:Attribute name="jobTitle> <attributeValue company="company1">CIO</attributeValue> <attributeValue company="company2">VP</attributeValue> </saml:Attribute> Which approach will you prefer? Why? I am biased towards second approach as it does not require client to know about any schema. It does require them to know about non-standard attribute company in the attribute value.

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• IDN aware tools to encode/decode human readable IRI to/from valid URI

  - by Denis Otkidach

  Let's assume a user enter address of some resource and we need to translate it to: <a href="valid URI here">human readable form</a> HTML4 specification refers to RFC 3986 which allows only ASCII alphanumeric characters and dash in host part and all non-ASCII character in other parts should be percent-encoded. That's what I want to put in href attribute to make link working properly in all browsers. IDN should be encoded with Punycode. HTML5 draft refers to RFC 3987 which also allows percent-encoded unicode characters in host part and a large subset of unicode in both host and other parts without encoding them. User may enter address in any of these forms. To provide human readable form of it I need to decode all printable characters. Note that some parts of address might not correspond to valid UTF-8 sequences, usually when target site uses some other character encoding. An example of what I'd like to get: <a href="http://xn--80aswg.xn--p1ai/%D0%BF%D1%83%D1%82%D1%8C?%D0%B7%D0%B0%D0%BF%D1%80%D0%BE%D1%81"> http://????.??/???????????</a> Are there any tools to solve these tasks? I'm especially interested in libraries for Python and JavaScript.

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• PHP: Array of objects is empty when I come to retrieve one from the array

  - by Tom

  Good morning, I am trying to load rows from a database and then create objects from them and add these objects to a private array. Here are my classes: <?php include("databaseconnect.php"); class stationItem { private $code = ''; private $description = ''; public function setCode($code ){ $this->code = $code; } public function getCode(){ return $this->code; } public function setDescription($description){ $this->description = $description; } public function getDescription(){ return $this->description; } } class stationList { private $stationListing; function __construct() { connect(); $stationListing = array(); $result = mysql_query('SELECT * FROM stations'); while ($row = mysql_fetch_assoc($result)) { $station = new stationItem(); $station->setCode($row['code']); $station->setDescription($row['description']); array_push($stationListing, $station); } mysql_free_result($result); } public function getStation($index){ return $stationListing[$index]; } } ?> As you can see I am creating a stationItem object per database row (which for now has a code and description) and I then push these on to the end of my array which is held as a private variable in stationList. This is code which creates this classes and attempts to access the properties on them: $stations = new stationList(); $station = $stations->getStation(0); echo $station->getCode(); I am finding that the sizeof($stationList) at the end of the constructor is 1 but then it is zero when we come to try to get an object from the array using the index. Therefore the error that I get is: Fatal error: Call to a member function getCode() on a non-object Please can someone explain to me why this is happening? I guess I am misunderstanding how object references work in PHP5.

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• Cocoa Core data: cannot save Created Items in NSTableview

  - by Paul Rostorp

  Hello, I'm am a beginner in mac os x development and am trying to get started with all this. Here is my problem : I've create a non-document based cocoa app using core data as storage. I've added an entity and attributes to the xdatamodel. In IB i've created an NSArrayController and linked it properly. I've created an nstableview binded to the nsarraycontroller. Next I added a button linked to nsarraycontroller with the " add: " method. When I try it out, I can add and edit the items in the table. Here comes the problem: Core data is supposed to save everything automatically, but to make sure i linked the "save" button in the menu to the appdelegate and to the " file's owner" , first responder, application... everything possible ( with both " save :" and " saveaction:" methods ). And still it doesn't save when clicking save: when I restart the cell created ( and renamed ) are gone. And also, I didn't even edit the source code yet; core data for such simple tasks is supposed to only need Interface builder. Please help me for this, I haven't found any threads resolving this problem. Thank you in advance.

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• Replacing/Extending Visual Studio's Generate Stub in Visual Studio 2010

  - by devoured elysium

  When we write the name of a method that doesn't exist, Visual Studio 2010 asks us if we'd like to generate a method stub with that name. What I'd like to know if is it possible to replace that same code stub generating command with one made by myself. I never did any kind of extensibility programming for Visual Studio so I have a couple of questions: How hard is it? Is it something I can learn in a couple of nights, or is it something that'll make me "lose" a lot of time? It seems to me that there isn't a lot of support for that kind of programming, as generally people are not that interested in developing solutions that extend the Visual Studio IDE. I searched on SO and it doesn't appear to have many threads about extending Visual Studio. I don't know how the generate method stub thing works in Visual Studio, but I just wanted to turn it into something a bit more flexible and useful. Has anyone dealt with these kind of things before, that can give me a pointer to where to start? I know of MS VSX site but that has a lot of resources and can be overwhelming for someone new to the subject as I am. What technology will I need to use? T4? Maybe I'll need to know a lot about the code, like Visual Studio does, so I can know other method's type arguments, names, etc. Is that what T4 is for? Thanks

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• After Navigate2 Method returns S_OK Stuck at READYSTATE of READYSTATE_LOADING

  - by Stone Free

  I am working on a MFC Document View architecture application which has multiple documents and views and a tabbed window interface. I have been tasked with making an automatic switch to another tab on the press of the OK button in one of the other tabs. When the other tab is clicked on it uses a C++ wrapper over IWebBrowser2 to navigate to a specific web page. When this is done manually by clicking on the tab everything is fine and the webpage within the view loads successfully. In my first attempt at doing this the tab successfully switched in response to a call to AfxGetMainWnd()->SendMessageToDescendants(SOME_MESSAGE, ...); however by sending this windows message at the wrong point the application would crash once control returned because the chain of events caused the (modeless) dialog (*) that sent the message, to no longer exist. I then found the correct place to make the call, but now when the other tab is activated, it no longer displays the webpage as it should. To debug this problem I added code to check the READYSTATE in both the situation where it works and the situation where it does not. When the page fails to load (despite the call to Navigate2 returning S_OK), the READYSTATE just stays at READYSTATE_LOADING. Unfortunately now I am to many edits away from when I had it partially working. I have added TRACE statements to the most obvious events such as OnSetFocus, CView::OnActivateView but all traces come out in the same order despite the behaviour being different * hosted in the view

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• diffie-hellman ssh keyxchange

  - by Chuck

  Hi, I've set out to make a primitive SSH client in C#; you might remember me from posts such as http://stackoverflow.com/questions/2872279/c-primitive-ssh-connection-lowlevel hehe. Anyway, things are great up until the time when I initiate a DH key exchange. I've compared the traffic when I establish a ssh connection (from openssh client to openssh server), to the traffic when my client connects to the same openssh server. OpenSSH client - OpenSSH server (S for server, C for client): S: SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2\r (saying hello) C: SSH-2.0-OpenSSH_5.2\r (introducing myself) C: Key Exchange Init (0x14 = 20) S: Key Exchange Init C: Diffie-Hellman GEX Request (0x22 = 34) (with DH GEX min, number of bits and max) S: Diffie-Hellman Key Exchange Reply (with P, G, etc.) C: Diffie-Hellman GEX Init S: Diffie-Hellman GEX Reply My client - OpenSSH server: S: SSH-2.0-OpenSSH_5.1p1 Debian-6ubuntu2\r (saying hello) C: SSH-2.0-Some_Name\r (introducing myself) C: Key Exchange Init (0x14 = 20) S: Key Exchange Init C: Diffie-Hellman GEX Request (0x22 = 34) (with DH GEX min, number of bits and max) and then a bogus TCP packet as reply (probably the server connection has been terminated after/upon GEX Request. I have yet to use AES128 (which I think is the encryption chosen, but I'm not sure how to verify this...), and I'm still sending in a non-compressed format, looking to get the P, G etc. values to make the DH calculations. So where I'm stranded is: RFC 4419 page 3 http://www.ietf.org/rfc/rfc4419.txt I've send SSH_MSG_KEY_DH_GEX_REQUEST, but the server does not respond SSH_MSG_KEX_DH_GEX_GROUP. Can anyone give me a little advice on what I'm not understanding here? Does the server not understand my GEX request (due to it expecting encryption, or?)? Any help is very much appreciated, thanks :)

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• Can the Diamond Problem be really solved?

  - by Mecki

  A typical problem in OO programming is the diamond problem. I have parent class A with two sub-classes B and C. A has an abstract method, B and C implement it. Now I have a sub-class D, that inherits of B and C. The diamond problem is now, what implementation shall D use, the one of B or the one of C? People claim Java knows no diamond problem. I can only have multiple inheritance with interfaces and since they have no implementation, I have no diamond problem. Is this really true? I don't think so. See below: [removed vehicle example] Is a diamond problem always the cause of bad class design and something neither programmer nor compiler needs to solve, because it shouldn't exist in the first place? Update: Maybe my example was poorly chosen. See this image Of course you can make Person virtual in C++ and thus you will only have one instance of person in memory, but the real problem persists IMHO. How would you implement getDepartment() for GradTeachingFellow? Consider, he might be student in one department and teach in another one. So you can either return one department or the other one; there is no perfect solution to the problem and the fact that no implementation might be inherited (e.g. Student and Teacher could both be interfaces) doesn't seem to solve the problem to me.

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• Handling one-to-many relationship with ZF partialLoop

  - by snaken

  Lets say i'm listing musical artists, each artist has basic information like Name, Age etc. stored in an artist table. They also have entries in an Albums table (album name/album cover etc), referencing the artist table using the artist id as a foreign key. I have the Model_Artist (Artist.php) file: class Model_Artist extends Zend_Db_Table_Abstract { protected $_name = 'artist'; protected $_dependentTables = array('Model_ArtistAlbums'); public function fetchArtistss() { $select = $this->select(); return $this->fetchAll($select); } } and to the Model_ArtistAlbums (ArtistAlbums.php) file class Model_ArtistAlbums extends Zend_Db_Table_Abstract { protected $_name = 'albums'; protected $_referenceMap = array( 'Artists' => array( 'columns' => 'alb_art_id', 'refTableClass' => 'Model_Artist', 'refColumns' => 'art_id' ) ); // etc } in my controller: public function indexAction() { /* THIS WORKS $art = new Model_Artist(); $artRowset = $art->find(1); $art1 = $artRowset->current(); $artalbums = $art1->findDependentRowset('Model_ArtistAlbums'); foreach($artalbums as $album){ echo $album->alb_title."<br>"; } */ $arts = new Model_Artist(); $this->view->artists = $arts->fetchArtists(); } in the view file: $this->partial()->setObjectKey('artist'); echo $this->partialLoop('admin/list-artists.phtml', $this->artists); but with this code in artists/list-artists.phtml: foreach($this->artist->findDependentRowset('albums') as $album): // other stuff endforeach; i get this error: Fatal error: Call to a member function findDependentRowset() on a non-object A var_dump of $this->artist = NULL.

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• Losing 'post' requests sent to Pylons paster server

  - by Philip McDermott

  I'm sending post requests to a Pylons server (served by paster serve), and if I send them with any frequency many don't arrive at the server. One at a time is ok, but if I fire off a few (or more) within seconds, only a small number get dealt with. If I send with no post data, or with get, it works fine, but putting just one character of data in the post fields causes massive losses. For example, sending 200, 2 will come back. Sending 100 more slowly, 10 will come back. I'm making the requests form inside a Qt application. Tis will work ok (no data): QString postFields = "" QNetworkRequest request(QUrl("http://server.com/endpoint")); QNetworkReply *reply = networkAccessManager-post(request, postFields.toAscii()); And this will result in only a fraction of the requests being dealt with: QString postFields = "" QNetworkRequest request(QUrl("http://server.com/endpoint")); QNetworkReply *reply = networkAccessManager-post(request, postFields.toAscii()); I've played around with turning on use_threadpool, and other options (threadpool_workers, threadpool_max_requests = 300), of which some combinations can alter the results slightly (best case 10 responses in 200). If I send similar requests to other (non paster) servers, the replies come back ok, so I'm almost certain its'a paster serve config issue. Any help or advice greatly appreciated. Thanks Philip

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• How to implement Excel Solver functionality in C#?

  - by Vic

  Hi, I have an application in C#, I need to do some optimization calculations, like Excel Solver Add-in does, one option is certainly to write my own solver implementation, but I'm kind of short of time, so I'm looking into libraries that already exist that can help me with this. I've been trying the Microsoft Solver Foundation, which seems pretty neat and cool, the problem is that it doesn't seem to work with the kind of calculations that I need to do. At the end of this question I'm adding the information about the calculations I need to perform and optimize. So basically my question is if any of you know of any other library that I can use for this purpose, or any tutorial that can help to do my own solver, or any idea that gives me a lead to solve this issue. Thanks. Additional Info: This is the data I need to calculate: I have 7 variables, lets call them var1, var2,...,var7 The constraints for these variables are: All of them need to be 0 <= varn <= 0.5 (where n is the number of the variable) The sum of all the variables should be equal to 1 The objective is to maximize the target formula, which in Excel looks like this: (MMULT(TRANSPOSE(L26:L32),M14:M20)) / (SQRT(MMULT(MMULT(TRANSPOSE(L26:L32),M4:S10),L26:L32))) The range that you see in this formula, L26:L32, is actually the range with the variables from above, var1, var2,..., varn. M14:M20 and M4:S10 are ranges with data that I get from different sources, there are more likely decimal values. As I said before, I was using Microsoft Solver Foundation, I modeled pretty much everything with it, I created functions that handle the operations of the target formula, but when I tried to solve the model it always fail, I think it is because of the complexity of the operations. In any case, I just wanted to show these data so you can have an idea about the kind of calculations that I need to implement.

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• Practical size limitations for RDBMS

  - by grenade

  I am working on a project that must store very large datasets and associated reference data. I have never come across a project that required tables quite this large. I have proved that at least one development environment cannot cope at the database tier with the processing required by the complex queries against views that the application layer generates (views with multiple inner and outer joins, grouping, summing and averaging against tables with 90 million rows). The RDBMS that I have tested against is DB2 on AIX. The dev environment that failed was loaded with 1/20th of the volume that will be processed in production. I am assured that the production hardware is superior to the dev and staging hardware but I just don't believe that it will cope with the sheer volume of data and complexity of queries. Before the dev environment failed, it was taking in excess of 5 minutes to return a small dataset (several hundred rows) that was produced by a complex query (many joins, lots of grouping, summing and averaging) against the large tables. My gut feeling is that the db architecture must change so that the aggregations currently provided by the views are performed as part of an off-peak batch process. Now for my question. I am assured by people who claim to have experience of this sort of thing (which I do not) that my fears are unfounded. Are they? Can a modern RDBMS (SQL Server 2008, Oracle, DB2) cope with the volume and complexity I have described (given an appropriate amount of hardware) or are we in the realm of technologies like Google's BigTable? I'm hoping for answers from folks who have actually had to work with this sort of volume at a non-theoretical level.

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• What are the most interesting equivalences arising from the Curry-Howard Isomorphism?

  - by Tom

  I came upon the Curry-Howard Isomorphism relatively late in my programming life, and perhaps this contributes to my being utterly fascinated by it. It implies that for every programming concept there exists a precise analogue in formal logic, and vice versa. Here's an "obvious" list of such analogies, off the top of my head: program/definition | proof type/declaration | proposition inhabited type | theorem function | implication function argument | hypothesis/antecedent function result | conclusion/consequent function application | modus ponens recursion | induction identity function | tautology non-terminating function | absurdity tuple | conjunction (and) disjoint union | exclusive disjunction (xor) parametric polymorphism | universal quantification So, to my question: what are some of the more interesting/obscure implications of this isomorphism? I'm no logician so I'm sure I've only scratched the surface with this list. For example, here are some programming notions for which I'm unaware of pithy names in logic: currying | "((a & b) => c) iff (a => (b => c))" scope | "known theory + hypotheses" And here are some logical concepts which I haven't quite pinned down in programming terms: primitive type? | axiom set of valid programs? | theory ? | disjunction (or)

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• Vim with Powershell

  - by Kevin Berridge

  I'm using gvim on Windows. In my _vimrc I've added: set shell=powershell.exe set shellcmdflag=-c set shellpipe=> set shellredir=> function! Test() echo system("dir -name") endfunction command! -nargs=0 Test :call Test() If I execute this function (:Test) I see nonsense characters (non number/letter ASCII characters). If I use cmd as the shell, it works (without the -name), so the problem seems to be with getting output from powershell into vim. Interestingly, this works great: :!dir -name As does this: :r !dir -name UPDATE: confirming behavior mentioned by David If you execute the set commands mentioned above in the _vimrc, :Test outputs nonsense. However, if you execute them directly in vim instead of in the _vimrc, :Test works as expected. Also, I've tried using iconv in case it was an encoding problem: :echo iconv( system("dir -name"), "unicode", &enc ) But this didn't make any difference. I could be using the wrong encoding types though. Anyone know how to make this work?

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• what does this asp.net mvc compile time error states?

  - by Pandiya Chendur

  I have a repository class and it has this, using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using CrMVC.BusinessObjects; namespace CrMVC.Models { public class ConstructionRepository { private CRDataContext db = new CRDataContext(); public IQueryable<MaterialsObj> FindAllMaterials() { var materials = from m in db.Materials join Mt in db.MeasurementTypes on m.MeasurementTypeId equals Mt.Id select new MaterialsObj() { Id = Convert.ToInt64(m.Mat_id), Mat_Name = m.Mat_Name, Mes_Name = Mt.Name, }; return materials; } } } And My MaterialsObj class is under CrMVC.BusinessObjects namespace and i using it in my repository class.... namespace CrMVC.BusinessObjects { public class MaterialsObj { //My logic here } } But when i compile this i get this error c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\19360d4c\3d21e226\App_Web_materials.aspx.7d2669f4.a8f-zsw5.0.cs(148): error CS0426: The type name 'Materials' does not exist in the type 'CrMVC.Models.ConstructionRepository' Am i missing something any suggestion.... Edit: There is no class named Materials in my repository class then why i get this error..

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• How to check for mutual existence of Fields in same table in Two columns

  - by ranabra

  I tried using "Exist" and "IN". Not only did I not succeed, it didn't seem as an efficient solution. Here is a simplified example: TblMyTable WorkerUserName  -  WorkerDegree  -  ManagerUserName  -  ManagerDegree I need a query where there is a mutual connection / existence. What I mean is only where the worker, ex. "John" has a manager named "Mary", and where Mary the manager has a worker named "John". John the worker can have several managers and Mary the manager can have several workers. So the result will be (the order doesn't matter) ideally in one line: John - BSc  --  Mary - M.A. or Mary - M.A.  --  John - BSc The punchline is it's only one table. it is not really managers and workers, this is just a simplification of the situation. In the real situation both are equal, in a Table of names of users working with other users. Database is SQL 2005. Many thanx in advance  

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• html5 vs flash - full comparison chart anywhere?

  - by iddqd

  So since Steve Jobs said Flash sucks and implied that HTML5 can do everything Flash can without the need for a Plugin, I keep hearing those exact words from a lot of People. I would really like to have a Chart somewhere (similar to http://en.wikipedia.org/wiki/Comparison_of_layout_engines_%28HTML5%29#Form_elements_and_attributes ) that I can just show to those people. Showing all the little things that Flash can do right now, that HTML5/Ajax/CSS is not yet even thinking about. But of course also the things that HTML5 does better. I would like to see details compared like audio playback, realtime audio processing, byte level access, bitmap data manipulation, webcam access, binary sockets, stuff in the works such as P2P technology (adobe stratus) and all the stuff I don't know about myself. Ideally with examples of what can be accomplished with, lets say Binary Sockets (such as a POP3 client) because otherwise it won't mean a lot to non-programmers since they will just say "well we can do without Binary Sockets". And ideally with some current benchmarks and some examples of websites that use this technology. I've searched the web and am surprised not to find anything. So is there such a comparison somewhere? Or does anybody want to create this and post it to Wikipedia? ;-)

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