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  • Multidimensional data structure?

    - by Austin Truong
    I need a multidimensional data structure with a row and a column. Must be able to insert elements any location in the data structure. Example: {A , B} I want to insert C in between A and B. {A, C, B}. Dynamic: I do not know the size of the data structure. Another example: I know the [row][col] of where I want to insert the element. EX. insert("A", 1, 5), where A is the element to be inserted, 1 is the row, 5 is the column. EDIT I want to be able to insert like this. static void Main(string[] args) { Program p = new Program(); List<string> list = new List<string>(); list.Insert(1, "HELLO"); list.Insert(5, "RAWR"); for (int i = 0; i < list.Count; i++) { Console.WriteLine(list[i]); } Console.ReadKey(); } And of course this crashes with an out of bounds error. So in a sense I will have a user who will choose which ROW and COL to insert the element to.

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  • Complicated SQL query

    - by Yandawl
    Please bare with me this is difficult to explain xD http://img90.imageshack.us/i/croppercapture1.png/ This is based on an undergraduate degree course where a student takes many units (say 4 core units and 1 optional unit per year). tblAwardCoreUnits and tblAwardOptUnits store which units are optional and core for which award, hence the relationship to tblAward and tblStudentCoreUnits and tblStudentOptUnits store the particular instances of those units which a particular student is taking. Secondly, a unit can have multiple events (say a lecture and a unit) and each of those events has sessions in which a student can attend, hence tblEvents, tblSessions and tblAttendances. The query I am trying to produce is to get a list of all level one students, grouped by their award that lists the percentage of attendances in all the units in the current level. I've tried and tried with this and the following is the best I've managed to come up with so far... I'd REALLY appreciate any help you can give with this! SELECT tblStudents.enrolmentNo, tblStudents.forename, tblStudents.surname, tblAwards.title, (SELECT COUNT((tblAttendances.attended + tblAttendances.authorisedAbsence)) AS SumOfAttendances FROM tblAttendances INNER JOIN (tblStudents ON tblStudents.enrolmentNo = tblAttendances.enrolmentNo)) / FROM tblUnits, tblAwards INNER JOIN ((tblStudents INNER JOIN tblStudentOptUnit ON tblStudents.studentID = tblStudentOptUnit.studentID) INNER JOIN tblStudentCoreUnit ON tblStudents.studentID = tblStudentCoreUnit.studentID) ON tblAwards.awardID = tblStudents.awardID WHERE (((tblStudents.level)="1") AND ((tblStudents.status)="enrolled")) GROUP BY tblAwards.title ORDER BY tblStudents.forname;

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  • Pump Messages During Long Operations + C# (it is urgent)

    - by Newbie
    Hi I have a web service that is doing huge computation and is taking more than a minute. I have generated the proxy file of the web service and then from my client end I am using the dll(of course I generated the proxy dll). My client side code is TimeSeries3D t = new TimeSeries3D(); int portfolioId = 4387919; string[] str = new string[2]; str[0] = "MKT_CAP"; DateRange dr = new DateRange(); dr.mStartDate = DateTime.Today; dr.mEndDate = DateTime.Today; Service1 sc = new Service1(); t = sc.GetAttributesForPortfolio(portfolioId, true, str, dr); But since it is taking to much time for the server to compute, after 1 minute I am receiving an error message The CLR has been unable to transition from COM context 0x33caf30 to COM context 0x33cb0a0 for 60 seconds. The thread that owns the destination context/apartment is most likely either doing a non pumping wait or processing a very long running operation without pumping Windows messages. This situation generally has a negative performance impact and may even lead to the application becoming non responsive or memory usage accumulating continually over time. To avoid this problem, all single threaded apartment (STA) threads should use pumping wait primitives (such as CoWaitForMultipleHandles) and routinely pump messages during long running operations. Kindly guide me what to do? It is very urgent. Thanks

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  • Is this a hole in dynamic binding in C# 4?

    - by Galilyou
    I've seen a very interesting post on Fabio Maulo's blog. Here's the code and the bug if you don't want to jump to the url. I defined a new generic class like so: public class TableStorageInitializer<TTableEntity> where TTableEntity : class, new() { public void Initialize() { InitializeInstance(new TTableEntity()); } public void InitializeInstance(dynamic entity) { entity.PartitionKey = Guid.NewGuid().ToString(); entity.RowKey = Guid.NewGuid().ToString(); } } Note that InitializeInstance accepts one parameter, which is of type dynamic. Now to test this class, I defined another class that is nested inside my main Program class like so: class Program { static void Main(string[] args) { TableStorageInitializer<MyClass> x = new TableStorageInitializer<MyClass>(); x.Initialize(); } private class MyClass { public string PartitionKey { get; set; } public string RowKey { get; set; } public DateTime Timestamp { get; set; } } } Note: the inner class "MyClass" is declared private. Now if i run this code I get a "Microsoft.CSharp.RuntimeBinder.RuntimeBinderException" on the line "entity.PartitionKey = Guide.NewGuid().ToString()". The interesting part, though is that the message of the exception says "Object doesn't contain a definition for PartitionKey". Also note that if you changed the modifier of the nested class to public, the code will execute with no problems. So what do you guys think is really happening under the hood? Please refer to any documentation -of course if this is documented anywhere- that you may find?

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  • Apache proxy to Lighttpd: changing $_SERVER['HTTP_HOST'] in php

    - by watain
    I have a WordPress blog running on lighttpd-1.4.19, listening on at www00:81. On the same host, apache-2.2.11 listens on port 80, which creates a proxy connection from http://blog.mydomain.org:80 to http://blog.mydomain.org:81. The Apache virtualhost looks as follows: <VirtualHost *:80> ServerName blog.mydomain.org ProxyRequests Off <Proxy *> Order deny,allow Allow from all </Proxy> ProxyPass / http://blog.mydomain.org:81/ ProxyPassReverse / http://blog.mydomain.org:81/ </VirtualHost> Using debug.log-request-handling = "enable" I get the following log entry when I browse http://blog.mydomain.org:80 (notice the Host headers): 2010-05-10 08:47:14: (request.c.294) fd: 6 request-len: 853 GET / HTTP/1.1 Host: blog.mydomain.org:81 [...] 2010-05-10 08:47:15: (request.c.294) fd: 8 request-len: 754 GET /wp-content/uploads/2010/01/image.gif?w=280 HTTP/1.1 Host: www00:81 My problem: as far as I know, the PHP environment variable $_SERVER['HTTP_HOST'] is set to that Host header variable. Unfortunately, WordPress uses that variable in their system to create URLs to pictures on the blog. These URLs won't be accessible behind a firewall of course. How can I force the host header to be blog.mydomain.org instead of blog.mydomain.org:81, respectively www00:81? I already added set server.name = "blog.mydomain.org" to my lighttpd.conf, but this didn't work. Any suggestions are appreciated, thank you.

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  • Which technology should I use to transform my latex documents into html documents

    - by Matthias Günther
    Hey, I want to write a little program that transforms my TeX files into HTML. I want to parse the documents and turn the macros (the build-in and of course my own) into HTML pieces. Here are my requirements: predefined rules (e.g. begin{itemize} \item text \end{itemize} = <br> <p>text </p> <br/>) defining own CSS style ability to convert formulars (extract the formulars, load them in an imagecreator and then save the jpg/png) easy to maintain and concise I know there are several technologies out there, but I don't exactly know which is the best for me. Here are the technologies which flow into my mind Ruby (I/O is easy, formular loading via webrat), XML XSLT (I don't think that I need just overhead) perl (there are many libs out there but I'm not quite familiar with it) bash (I worked with sed and was surprised how easy it was to work with regular expressions) latex2html ... (these converters won't work for me and they don't give me freedom in parsing) Any suggestions, hints and comments are welcome. Thanks for your time, folks.

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  • Do I need to implement an XMPP server?

    - by WTFITS
    (newbie alert) I need to program a multiparty communication service for a course project, and I am considering XMPP for it. The service needs following messaging semantics: 1) server will provide a method of registering and unregistering an address such as [email protected]/SomeResource. (for now I will do it manually). 2) server will provide a method of forwarding incoming messages from, say, [email protected]/SomeResource to [email protected]/someOtherResource, assuming that the latter is registered, and a method for removing this forwarding. (for now I will do it manually). 3) anonymous clients can send messages to, say, [email protected]/someresource (one way traffic only). If there is any forwarding setup, the message will be forwarded. Finally if the address is [email protected]/someresource is registered, the message will be stored for later delivery (or immediate if a retrieving client is online - see below). If no forwarding and unregistered, message will be silently dropped. 4) clients can connect and retrieve messages from a registered address. Exact method of authenticating clients (e.g., passwords?) is yet to be determined. Eventually, I want to add support for clients to connect from a web browser so they can register/unregister and set/remove forwarding themselves. Thus, the server will have to do some non-standard switching. Will I need to implement an XMPP server for this? I guess some (or all?) of this can also be done using a XMPP client bot

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  • Type-safe mapping from Class<T> to Thing<T>

    - by Joonas Pulakka
    I want to make a map-kind of container that has the following interface: public <T> Thing<T> get(Class<T> clazz); public <T> void put(Class<T> clazz, Thing<T> thing); The interesting point is that the Ts in each Class<T><- Thing<T> pair is the same T, but the container should be able to hold many different types of pairs. Initially I tried a (Hash)Map. But, for instance, Map<Class<T>, Thing<T>> is not right, because then T would be same T for all pairs in that map. Of course, Map<Class<?>, Thing<?>> works, but then I don't have type-safety guarantees so that when I get(String.class), I can't be sure that I get a Thing<String> instance back. Is there a way to accomplish the kind of type safety that I'm looking for?

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  • Database for managing large volumes of (system) metrics

    - by symcbean
    Hi, I'm looking at building a system for managing and reporting stats on web page performance. I'll be collecting a lot more stats than are available in the standard log formats (approx 20 metrics) but compared to most types of database applications, the base data structure will be very simple. My problem is that I'll be accumulating a lot of data - in the region of 100,000 records (i.e. sets of metrics) per hour. Of course, resources are very limited! So that its possible to sensibly interact with the data, I'd need to consolidate each metric into one minute bins, broken down by URL, then for anything more than 1 day old, consolidated into 10 minute bins, then at 1 week, hourly bins. At the front end, I want to provide a view (prefereably as plots) of the last hour of data, with the facility for users to drill up/down through defined hierarchies of URLs (which do not always map directly to the hierarchy expressed in the path of the URL) and to view different time frames. Rather than coding all this myself and using a relational database, I was wondering if there were tools available which would facilitate both the management of the data and the reporting. I had a look at Mondrian however I can't see from the documentation I've looked at whether it's possible to drop the more granular information while maintaining the consolidated views of the data. RRDTool looks promising in terms of managing the data consolidation, but seems to be rather limited in terms of querying the dataset as a multi-dimensional/relational database. What else whould I be looking at?

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  • how do i implement / build / create an 'in memory database' for my unit test

    - by Michel
    Hi all, i've started unit testing a while ago and as turned out i did more regression testing than unit testing because i also included my database layer thus going to the database verytime. So, implemented Unity to inject a fake database layer, but i of course want to store some data, and the main opinion was: "create an in-memory database" But what is that / how do i implement that? Main question is: i think i have to fake the database layer, but doesn't that make me create a 'simple database' myself or: how can i keep it simple and not rebuilding Sql Server just for my unit tests :) At the end of this question i'll give an explanation of the situation i got in on the project i just started on, and i was wondering if this was the way to go. Michel Current situation i've seen at this client is that testdata is contained in XML files, and there is a 'fake' database layer that connects all the xml files together. For the real database we're using the entity framework, and this works very simple. And now, in the 'fake' layer, i have top create all kind of classes to load, save, persist etc. the data. It sounds weird that there is so much work in the fake layer, and so little in the real layer. I hope this all makes sense :)

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  • 60K+ Sprites on the 360?

    - by Jeffrey Kern
    Hey everyone, Just wondering - throwing ideas in my head - about starting a new XNA project for the 360. I would like it to be retro-old school, and emulating scanlines and color palettes and such. As part of this idea, what I would ideally like to do is manually draw each and every pixel of the screen. So, worst-case scenario I would have to draw about 60K sprites on a 252x240 resolution (I think thats correct). 60K sprites on the screen at a time. So, before I even attempt to code this - would the XBOX 360 be able to keep up with this even? That is a lot of sprites, but they aren't big sprites, and the texture data needed would be non-existant. However, I guess how this project would be implemented would make it or break it, but all I was thinking was coming up with a 2D array and mapping which color value would need to be drawn at that point. Of course, this is watered down talk right now. But what you all suggest? EDIT: Each sprite would represent one pixel. E.g., a sprite at 0,0. Another at 0,1. etc.

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  • Put together tiles in android sdk and use as background

    - by Jon
    In a feeble attempt to learn some Android development am I stuck at graphics. My aim here is pretty simple: Take n small images and build a random image, larger than the screen with possibility to scroll around. Have an animated object move around on it I have looked at the SDK examples, Lunar Lander especially but there are a few things I utterly fail to wrap my head around. I've got a birds view plan (which in my head seems reasonably sane): How do I merge the tiles into one large image? The background is static so I figure I should do like this: Make a 2d array with refs to the tiles Make a large Drawable and draw the tiles on it At init draw this big image as the background At each onDraw redraw the background of the previous spot of the moving object, and the moving object at its new location The problem is the hands on things. I load the small images with "Bitmap img1 = BitmapFactory.decodeResource (res, R.drawable.img1)", but then what? Should I make a canvas and draw the images on it with "canvas.drawBitmap (img1, x, y, null);"? If so how to get a Drawable/Bitmap from that? I'm totally lost here, and would really appreciate some hands on help (I would of course be grateful for general hints as well, but I'm primarily trying to understand the Graphics objects). To make you, dear reader, see my level of confusion will I add my last desperate try: Drawable drawable; Canvas canvas = new Canvas (); Bitmap img1 = BitmapFactory.decodeResource (res, R.drawable.img1); // 50 x 100 px image Bitmap img2 = BitmapFactory.decodeResource (res, R.drawable.img2); // 50 x 100 px image canvas.drawBitmap (img1, 0, 0, null); canvas.drawBitmap (img2, 50, 0, null); drawable.draw (canvas); // obviously wrong as draw == null this.setBackground (drawable); Thanks in advance

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  • Confused about UIView frame property

    - by slowfungus
    I'm building a prototype iPad app that draws diagrams. I have the following view hierarchy: UIView UIScrollView DiagramView : UIView TabBar NavigationBar And a UIViewController subclass holding all that together. Before drawing the diagram the first time I calculate the dimensions of the diagram, and set the DiagramView frame to that size, and the content size of the scrollview as well. -(void)recalculateBounds { [renderer diagram:diagram shouldDraw:NO]; SQXRect diagramRect = SQXMakeRect(0.0,0.0,[diagram bounds].size.width,[diagram bounds].size.height); self.frame = diagramRect; [(UIScrollView*)[self superview] setContentSize:diagramRect.size]; } I should disclose that the frame is being set to about 1500 x 3500 which i know is ridiculous. I just want to focus on some other parts of the app before I get into optimizing the render code. This works beautifully, except that the rect being passed to drawRect is not the size that I set, and my drawing is getting clipped at the bottom. Its close the size i set, but bigger in width, and shorter in height. Also of note, is the fact that if I force the frame to be much bigger than what I know the diagram needs, then the drawRect:rect is big enough, and no clipping occurs. Of course this has me wondering if the frame size needs to take into account some other screen real estate like the toolbars but my reading of the docs tells me the frame is in superview coordinates, which would be the scrollview so I reckon I need to worry about such things. Any idea what is causing this discrepancy?

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  • Runing bcdedit from python in Windows 2008 SP2

    - by Lee-Man
    I do not know windows well, so that may explain my dilemma ... I am trying to run bcdedit in Windows 2008R2 from Python 2.6. My Python routine to run a command looks like this: def run_program(cmd_str): """Run the specified command, returning its output as an array of lines""" dprint("run_program(%s): entering" % cmd_str) cmd_args = cmd_str.split() subproc = subprocess.Popen(cmd_args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True) (outf, errf) = (subproc.stdout, subproc.stderr) olines = outf.readlines() elines = errf.readlines() if Options.debug: if elines: dprint('Error output:') for line in elines: dprint(line.rstrip()) if olines: dprint('Normal output:') for line in olines: dprint(line.rstrip()) errf.close() outf.close() res = subproc.wait() dprint('wait result=', res) return (res, olines) I call this function thusly: (res, o) = run_program('bcdedit /set {current} MSI forcedisable') This command works when I type it from a cmd window, and it works when I put it in a batch file and run it from a command window (as Administrator, of course). But when I run it from Python (as Administrator), Python claims it can't find the command, returning: bcdedit is not recognized as an internal or external command, operable program or batch file Also, if I trying running my batch file from Python (which works from the command line), it also fails. I've also tried it with the full path to bcdedit, with the same results. What is it about calling bcdedit from Python that makes it not found? Note that I can call other EXE files from Python, so I have some level of confidence that my Python code is sane ... but who knows. Any help would be most appreciated.

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  • one table is shared between several websites

    - by sami
    I have a static table that's shared by several websites. By static, I mean that the data is read but never updated by the websites. Currently, all websites are served from the same server but that may change. I want to minimize the need for creating/maintaining this table for each of the websites, so I thought about turning it to an xml file that's stored in a shared library that all websites have access to. The problem is I use an ORM and use forign key constraints to ensure integrity of the ids used from that table, so by removing that table out of the MySQL database into an XML file, will this affect the integrity of the ids coming from that table? My table looks like this <table name="entry"> <column name="id" type="INTEGER" primaryKey="true" autoIncrement="true" /> <column name="title" type="VARCHAR" size="500" required="true" /> </table> and I use it as a foreign key in other tables <table name="refer"> <column name="id" type="INTEGER" primaryKey="true" autoIncrement="true" /> <column name="linkto" type="INTEGER"/> <foreign-key foreignTable="entry"> <reference local="linkto" foreign="id" /> </foreign-key> </table> So I'm wondering if I remove that table out of the database, is there a way to retain that referential integrity? And of course are these any other efficient ways to do the same thing? I just don't want to have to repeat that table for several websites.

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  • How are you supposed to layout a page in VS2010 without using tables?

    - by CrustyApple
    I have been using .NET since beta and HTML since the days of HotDog pro & notepad, using table layout of course. I am FINALLY ready to use only div, li, CSS for the layout, but my question is, what is the proper way to layout pages in VS2010? When i use table layout its simple and i can visually see what im creating and where the elements are, such as the sample below - how should I do this using div's, etc in VS2010? <table width="300" border="0" cellpadding="5"> <tr> <td><img src="http://assets.devx.com/MS_Azure/azuremcau.jpg" alt="blah" width="70" height="70" /></td> <td><h2>This is some text to the right of the picture...</h2></td> </tr> <tr> <td colspan="2">Here some text underneath</td> </tr> </table>

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  • I have a WPF/Silverlight ListView whose height is unpredictable and too high. How do I control it be

    - by Rob Perkins
    I have a ListView element with a DataTemplate for each ListViewItem defined as follows. When run, the ListView's height is not collapsed onto the items in the view, which is undesirable behavior: <DataTemplate x:Key="LicenseItemTemplate"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> </Grid.RowDefinitions> <TextBlock Grid.Row="0" Text="{Binding company}"></TextBlock> <Grid Grid.Row="1" Style="{StaticResource HiddenWhenNotSelectedStyle}"> <Grid.RowDefinitions> <RowDefinition /> </Grid.RowDefinitions> <Button Grid.Row="0">ClickIt</Button> </Grid> </Grid> </DataTemplate> The second row of the outer grid has a style applied which looks like this. The purpose of the style is to : <Style TargetType="{x:Type Grid}" x:Key="HiddenWhenNotSelectedStyle" > <Style.Triggers> <DataTrigger Binding="{Binding Path=IsSelected, RelativeSource={ RelativeSource Mode=FindAncestor, AncestorType={x:Type ListViewItem} } }" Value="False"> <Setter Property="Grid.Visibility" Value="Collapsed" /> </DataTrigger> <DataTrigger Binding="{Binding Path=IsSelected, RelativeSource={ RelativeSource Mode=FindAncestor, AncestorType={x:Type ListViewItem} } }" Value="True"> <Setter Property="Grid.Visibility" Value="Visible" /> </DataTrigger> </Style.Triggers> </Style> The ListView renders like this: The desired appearance is this, when none of the elements are selected: ...with, of course, the ListView's height adjusting to accommodate the additional content when the second grid is made visible by selection. What can I do to get the desired behavior?

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  • VS2010 Web Deploy: how to remove absolute paths and automate setAcl?

    - by Julien Lebosquain
    The integrated Web Deployment in Visual Studio 2010 is pretty nice. It can create a package ready to be deployed using MSDeploy on a target IIS machine. Problem is, this package will be redistributed to a client that will install it himself using the "Import Application" from IIS when MSDeploy is installed. The default package created always include the full path from the development machine, "D:\Dev\XXX\obj\Debug\Package\PackageTmp" in the source manifest file. It doesn't prevent installation of course since it was designed this way, but it looks ugly in the import dialog and has no meaning to the client. Worse he will wonder what are those paths and it looks quite confusing. By customizing the .csproj file (by adding MSBuild properties used by the package creation task), I managed to add additional parameters to the package. However, I spent most of the afternoon in the 2600 lines long Web.Publishing.targets trying to understand what parameter influenced the "development path" behavior, in vain. I also tried to use the setAcl to customize security on a given folder after deployment, but I only managed to do this with MSBuild by using a relative path... it shouldn't matter if I resolve the first problem though. I could modify the generated archive after its creation but I would prefer if everything was automatized using MSBuild. Does anyone know how to do that?

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  • Html.ListBox() and MultiselectList

    - by Ivan90
    Hi guys, I've a little problem with an Html.ListBox! I am developing a personal blog in ASP.NET MVC 1.0 and I created an adminpanel where I can add and edit a post! During this two operations, I can add also tags! I think of use an Html.ListBox() helper to list all tags, and so I can select multiple tags to add in a post! The problem isn't during the add mode, but in the edit mode, where I have to pre-select post's tags! I read that I have to use a MultiSelectList and so in its constructor pass, tags' list and tag's list(pre-selected value). But I don't know how to use this class! I post, some code: This is my models method that get all list tags in selectlist public IEnumerable<SelectListItem> GetTagsListBox() { return from t in db.Tags orderby t.IDTag descending select new SelectListItem { Text = t.TagName, Value = t.IDTag.ToString(), }; } So in Edit (Get and Post), Add(Get and Post) I use a ViewData to pass this list in Html.ListBox(). ViewData["Tags"] = tagdb.GetTagsListBox(); And in my view <%=Html.ListBox("Tags",ViewData["Tags"] as SelectList) %> So with this code it's ok in Add Mode! But in Edit Mode I need to pre-select those values! So Now, of course I have to create a method that get all tagsbypostid! and then in ViewData what Must I to pass? Any suggest?

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  • Converting to a column oriented array in Java

    - by halfwarp
    Although I have Java in the title, this could be for any OO language. I'd like to know a few new ideas to improve the performance of something I'm trying to do. I have a method that is constantly receiving an Object[] array. I need to split the Objects in this array through multiple arrays (List or something), so that I have an independent list for each column of all arrays the method receives. Example: List<List<Object>> column-oriented = new ArrayList<ArrayList<Object>>(); public void newObject(Object[] obj) { for(int i = 0; i < obj.length; i++) { column-oriented.get(i).add(obj[i]); } } Note: For simplicity I've omitted the initialization of objects and stuff. The code I've shown above is slow of course. I've already tried a few other things, but would like to hear some new ideas. How would you do this knowing it's very performance sensitive?

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  • Why are compilers so stupid?

    - by martinus
    I always wonder why compilers can't figure out simple things that are obvious to the human eye. They do lots of simple optimizations, but never something even a little bit complex. For example, this code takes about 6 seconds on my computer to print the value zero (using java 1.6): int x = 0; for (int i = 0; i < 100 * 1000 * 1000 * 1000; ++i) { x += x + x + x + x + x; } System.out.println(x); It is totally obvious that x is never changed so no matter how often you add 0 to itself it stays zero. So the compiler could in theory replace this with System.out.println(0). Or even better, this takes 23 seconds: public int slow() { String s = "x"; for (int i = 0; i < 100000; ++i) { s += "x"; } return 10; } First the compiler could notice that I am actually creating a string s of 100000 "x" so it could automatically use s StringBuilder instead, or even better directly replace it with the resulting string as it is always the same. Second, It does not recognize that I do not actually use the string at all, so the whole loop could be discarded! Why, after so much manpower is going into fast compilers, are they still so relatively dumb? EDIT: Of course these are stupid examples that should never be used anywhere. But whenever I have to rewrite a beautiful and very readable code into something unreadable so that the compiler is happy and produces fast code, I wonder why compilers or some other automated tool can't do this work for me.

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  • How can I pass in a params of Expression<Func<T, object>> to a method?

    - by Pure.Krome
    Hi folks, I have the following two methods :- public static IQueryable<T> IncludeAssociations<T>(this IQueryable<T> source, params string[] associations) { ... } public static IQueryable<T> IncludeAssociations<T>(this IQueryable<T> source, params Expression<Func<T, object>>[] expressions) { ... } Now, when I try and pass in a params of Expression<Func<T, object>>[], it always calls the first method (the string[]' and of course, that value isNULL`) Eg. Expression<Func<Order, object>> x1 = x => x.User; Expression<Func<Order, object>> x2 = x => x.User.Passport; var foo = _orderRepo .Find() .IncludeAssociations(new {x1, x2} ) .ToList(); Can anyone see what I've done wrong? Why is it thinking my params are a string? Can I force the type, of the 2x variables?

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  • Which languages support class replacement?

    - by Alix
    Hi, I'm writing my master thesis, which deals with AOP in .NET, among other things, and I mention the lack of support for replacing classes at load time as an important factor in the fact that there are currently no .NET AOP frameworks that perform true dynamic weaving -- not without imposing the requirement that woven classes must extend ContextBoundObject or MarshalByRefObject or expose all their semantics on an interface. You can however do this in Java thanks to ClassFileTransformer: You extend ClassFileTransformer. You subscribe to the class load event. On class load, you rewrite the class and replace it. All this is very well, but my project director has asked me, quite in the last minute, to give him a list of languages that do / do not support class replacement. I really have no time to look for this now: I wouldn't feel comfortable just doing a superficial research and potentially putting erroneous information in my thesis. So I ask you, oh almighty programming community, can you help out? Of course, I'm not asking you to research this yourselves. Simply, if you know for sure that a particular language supports / doesn't support this, leave it as an answer. If you're not sure please don't forget to point it out. Thanks so much!

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  • Help me write my LISP :) LISP environments, Ruby Hashes...

    - by MikeC8
    I'm implementing a rudimentary version of LISP in Ruby just in order to familiarize myself with some concepts. I'm basing my implementation off of Peter Norvig's Lispy (http://norvig.com/lispy.html). There's something I'm missing here though, and I'd appreciate some help... He subclasses Python's dict as follows: class Env(dict): "An environment: a dict of {'var':val} pairs, with an outer Env." def __init__(self, parms=(), args=(), outer=None): self.update(zip(parms,args)) self.outer = outer def find(self, var): "Find the innermost Env where var appears." return self if var in self else self.outer.find(var) He then goes on to explain why he does this rather than just using a dict. However, for some reason, his explanation keeps passing in through my eyes and out through the back of my head. Why not use a dict, and then inside the eval function, when a new "sub-environment" needs to be created, just take the existing dict and update the key/value pairs that need to be updated, and pass that new dict into the next eval? Won't the Python interpreter keep track of the previous "outer" envs? And won't the nature of the recursion ensure that the values are pulled out from "inner" to "outer"? I'm using Ruby, and I tried to implement things this way. Something's not working though, and it might be because of this, or perhaps not. Here's my eval function, env being a regular Hash: def eval(x, env = $global_env) ........ elsif x[0] == "lambda" then ->(*args) { eval(x[2], env.merge(Hash[*x[1].zip(args).flatten(1)])) } ........ end The line that matters of course is the "lambda" one. If there is a difference, what's importantly different between what I'm doing here and what Norvig did with his Env class? If there's no difference, then perhaps someone can enlighten me as to why Norvig uses the Env class. Thanks :)

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  • How to best launch C++ application from web page

    - by JB
    I guess there are two parts to this question, one technical and one best practice for security and doing things "right". I'm working on a little game using C++ / directx but I would like to be able to launch it from a web page by someone clicking on a link on that page. Ideally I would like the first time they clicked for it to launch an installer downloads and installs the game on their machine, and then the next time to launch an application which updates the game from a web site if it's old and then launches it. I have no problems with the expected security popups and questions the first time it runs. I want people to be certain what they are installing and understand what they are doing. But it would be nice if once it is installed they could run it with the minimum of fuss. My question then is what technologies I could use to do this? I'm thinking that it would need a browser plugin and an activex control so that first time you'd install that, and subsequently the control/plugin would be able to launch the game. I'm not sure that under newer browser secuity models that a plugin would have the permissions to be able to run an installer though or silently invoke applications on the client machine even if they are already installed. Is there a more sensible way to achive what I want to achieve? And I'm worried about the security aspects too. I want this to be convenient for users but I of course want to do it "right". I know this can be done as I've seen several mmorpg type games that launch in this way from the browser now but it's not entirely clear to me how they've done it.

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