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  • Windows in StreamInsight: Hopping vs. Snapshot

    - by Roman Schindlauer
    Three weeks ago, we explained the basic concept of windows in StreamInsight: defining sets of events that serve as arguments for set-based operations, like aggregations. Today, we want to discuss the so-called Hopping Windows and compare them with Snapshot Windows. We will compare these two, because they can serve similar purposes with different behaviors; we will discuss the remaining window type, Count Windows, another time. Hopping (and its syntactic-sugar-sister Tumbling) windows are probably the most straightforward windowing concept in StreamInsight. A hopping window is defined by its length, and the offset from one window to the next. They are aligned with some absolute point on the timeline (which can also be given as a parameter to the window) and create sets of events. The diagram below shows an example of a hopping window with length of 1h and hop size (the offset) of 15 minutes, hence creating overlapping windows:   Two aspects in this diagram are important: Since this window is overlapping, an event can fall into more than one windows. If an (interval) event spans a window boundary, its lifetime will be clipped to the window, before it is passed to the set-based operation. That’s the default and currently only available window input policy. (This should only concern you if you are using a time-sensitive user-defined aggregate or operator.) The set-based operation will be applied to each of these sets, yielding a result. This result is: A single scalar value in case of built-in or user-defined aggregates. A subset of the input payloads, in case of the TopK operator. Arbitrary events, when using a user-defined operator. The timestamps of the result are almost always the ones of the windows. Only the user-defined  operator can create new events with timestamps. (However, even these event lifetimes are subject to the window’s output policy, which is currently always to clip to the window end.) Let’s assume we were calculating the sum over some payload field: var result = from window in source.HoppingWindow( TimeSpan.FromHours(1), TimeSpan.FromMinutes(15), HoppingWindowOutputPolicy.ClipToWindowEnd) select new { avg = window.Avg(e => e.Value) }; Now each window is reflected by one result event:   As you can see, the window definition defines the output frequency. No matter how many or few events we got from the input, this hopping window will produce one result every 15 minutes – except for those windows that do not contain any events at all, because StreamInsight window operations are empty-preserving (more about that another time). The “forced” output for every window can become a performance issue if you have a real-time query with many events in a wide group & apply – let me explain: imagine you have a lot of events that you group by and then aggregate within each group – classical streaming pattern. The hopping window produces a result in each group at exactly the same point in time for all groups, since the window boundaries are aligned with the timeline, not with the event timestamps. This means that the query output will become very bursty, delivering the results of all the groups at the same point in time. This becomes especially obvious if the events are long-lasting, spanning multiple windows each, so that the produced result events do not change their value very often. In such a case, a snapshot window can remedy. Snapshot windows are more difficult to explain than hopping windows: they represent those periods in time, when no event changes occur. In other words, if you mark all event start and and times on your timeline, then you are looking at all snapshot window boundaries:   If your events are never overlapping, the snapshot window will not make much sense. It is commonly used together with timestamp modification, which make it a very powerful tool. Or as Allan Mitchell expressed in in a recent tweet: “I used to look at SnapshotWindow() with disdain. Now she is my mistress, the one I turn to in times of trouble and need”. Let’s look at a simple example: I want to compute the average of some value in my events over the last minute. I don’t want this output be produced at fixed intervals, but at soon as it changes (that’s the true event-driven spirit!). The snapshot window will include all currently active event at each point in time, hence we need to extend our original events’ lifetimes into the future: Applying the Snapshot window on these events, it will appear to be “looking back into the past”: If you look at the result produced in this diagram, you can easily prove that, at each point in time, the current event value represents the average of all original input event within the last minute. Here is the LINQ representation of that query, applying the lifetime extension before the snapshot window: var result = from window in source .AlterEventDuration(e => TimeSpan.FromMinutes(1)) .SnapshotWindow(SnapshotWindowOutputPolicy.Clip) select new { avg = window.Avg(e => e.Value) }; With more complex modifications of the event lifetimes you can achieve many more query patterns. For instance “running totals” by keeping the event start times, but snapping their end times to some fixed time, like the end of the day. Each snapshot then “sees” all events that have happened in the respective time period so far. Regards, The StreamInsight Team

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  • Webmasters hentry error and authorless pages

    - by Ben Racicot
    Within Google Webmasters Search Appearance-Structured data I'm getting a series of errors: Error: Missing required hCard "author". And most of my 44 errors have: Missing: Author Missing: entry-title Missing: updated There seems to be no CLEAR explanation of these errors. It is either because these classes exist without their nested classes, or they are expected to exist because of something else, possibly itemscope or itemtype='' The Question: How do you specify with richsnippets that the page is about a location and there is no human author?

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  • Part 8: How to name EBS Customizations

    - by volker.eckardt(at)oracle.com
    You might wonder why I am discussing this here. The reason is simple: nearly every project has a bit different naming conventions, which makes a the life always a bit complicated (for developers, but also setup responsible, and also for consultants).  Although we always create a document to describe the technical object naming conventions, I have rarely seen a dedicated document  with functional naming conventions. To be precisely, from my stand point, there should always be one global naming definition for an implementation! Let me discuss some related questions: What is the best convention for the customization reference? How to name database objects (tables, packages etc.)? How to name functional objects like Value Sets, Concurrent Programs, etc. How to separate customizations from standard objects best? What is the best convention for the customization reference? The customization reference is the key you use to reference your customization from other lists, from the project plan etc. Usually it is something like XXHU_CONV_22 (HU=customer abbreviation, CONV=Conversion object #22) or XXFA_DEPRN_RPT_02 (FA=Fixed Assets, DEPRN=Short object group, here depreciation, RPT=Report, 02=2nd report in this area) As this is just a reference (not an object name yet), I would prefer the second option. XX=Customization, FA=Main EBS Module linked (you may have sometimes more, but FA is the main) DEPRN_RPT=Short name to specify the customization 02=a unique number Important here is that the HU isn’t used, because XX is enough to mark a custom object, and the 3rd+4th char can be used by the EBS module short name. How to name database objects (tables, packages etc.)? I was leading different developer teams, and I know that one common way is it to take the Customization reference and add more chars behind to classify the object (like _V for view and _T1 for triggers etc.). The only concern I have with this approach is the reusability. If you name your view XXFA_DEPRN_RPT_02_V, no one will by choice reuse this nice view, as it seams to be specific for this CEMLI. My suggestion is rather to name the view XXFA_DEPRN_PERIODS_V and allow herewith reusability for other CEMLIs (although the view will be deployed primarily with CEMLI package XXFA_DEPRN_RPT_02). (check also one of the following Blogs where I will talk about deployment.) How to name Value Sets, Concurrent Programs, etc. For Value Sets I would go with the same convention as for database objects, starting with XX<Module> …. For Concurrent Programs the situation is a bit different. This “object” is seen and used by a lot of users, and they will search for. In many projects it is common to start again with the company short name, or with XX. My proposal would differ. If you have created your own report and you name it “XX: Invoice Report”, the user has to remember that this report does not start with “I”, it starts with X. Would you like typing an X if you are looking for an Invoice report? No, you wouldn’t! So my advise would be to name it:   “Invoice Report (XXAP)”. Still we know it is custom (because of the XXAP), but the end user will type the key “i” to get it (and will see similar reports starting also with “i”). I hope that the general schema behind has now become obvious. How to separate customizations from standard objects best? I would not have this section here if the naming would not play an important role. Unfortunately, we can not always link a custom application to our own object, therefore the naming is really important. In the file system structure we use our $XXyy_TOP, in JAVA_TOP it is perhaps also “xx” in front. But in the database itself? Although there are different concepts in place, still many implementations are using the standard “apps” approach, means custom objects are stored in the apps schema (which should not cause any trouble). Final advise: review the naming conventions regularly, once a month. You may have to add more! And, publish them! To summarize: Technical and functional customized objects should always follow a naming convention. This naming convention should be project wide, and only one place shall be used to maintain (like in a Wiki). If the name is for the end user, rather put a customization identifier at the end; if it is an internal name, start with XX…

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  • Mixing Forms and Token Authentication in a single ASP.NET Application (the Details)

    - by Your DisplayName here!
    The scenario described in my last post works because of the design around HTTP modules in ASP.NET. Authentication related modules (like Forms authentication and WIF WS-Fed/Sessions) typically subscribe to three events in the pipeline – AuthenticateRequest/PostAuthenticateRequest for pre-processing and EndRequest for post-processing (like making redirects to a login page). In the pre-processing stage it is the modules’ job to determine the identity of the client based on incoming HTTP details (like a header, cookie, form post) and set HttpContext.User and Thread.CurrentPrincipal. The actual page (in the ExecuteHandler event) “sees” the identity that the last module has set. So in our case there are three modules in effect: FormsAuthenticationModule (AuthenticateRequest, EndRequest) WSFederationAuthenticationModule (AuthenticateRequest, PostAuthenticateRequest, EndRequest) SessionAuthenticationModule (AuthenticateRequest, PostAuthenticateRequest) So let’s have a look at the different scenario we have when mixing Forms auth and WS-Federation. Anoymous request to unprotected resource This is the easiest case. Since there is no WIF session cookie or a FormsAuth cookie, these modules do nothing. The WSFed module creates an anonymous ClaimsPrincipal and calls the registered ClaimsAuthenticationManager (if any) to transform it. The result (by default an anonymous ClaimsPrincipal) gets set. Anonymous request to FormsAuth protected resource This is the scenario where an anonymous user tries to access a FormsAuth protected resource for the first time. The principal is anonymous and before the page gets rendered, the Authorize attribute kicks in. The attribute determines that the user needs authentication and therefor sets a 401 status code and ends the request. Now execution jumps to the EndRequest event, where the FormsAuth module takes over. The module then converts the 401 to a redirect (302) to the forms login page. If authentication is successful, the login page sets the FormsAuth cookie.   FormsAuth authenticated request to a FormsAuth protected resource Now a FormsAuth cookie is present, which gets validated by the FormsAuth module. This cookie gets turned into a GenericPrincipal/FormsIdentity combination. The WS-Fed module turns the principal into a ClaimsPrincipal and calls the registered ClaimsAuthenticationManager. The outcome of that gets set on the context. Anonymous request to STS protected resource This time the anonymous user tries to access an STS protected resource (a controller decorated with the RequireTokenAuthentication attribute). The attribute determines that the user needs STS authentication by checking the authentication type on the current principal. If this is not Federation, the redirect to the STS will be made. After successful authentication at the STS, the STS posts the token back to the application (using WS-Federation syntax). Postback from STS authentication After the postback, the WS-Fed module finds the token response and validates the contained token. If successful, the token gets transformed by the ClaimsAuthenticationManager, and the outcome is a) stored in a session cookie, and b) set on the context. STS authenticated request to an STS protected resource This time the WIF Session authentication module kicks in because it can find the previously issued session cookie. The module re-hydrates the ClaimsPrincipal from the cookie and sets it.     FormsAuth and STS authenticated request to a protected resource This is kind of an odd case – e.g. the user first authenticated using Forms and after that using the STS. This time the FormsAuth module does its work, and then afterwards the session module stomps over the context with the session principal. In other words, the STS identity wins.   What about roles? A common way to set roles in ASP.NET is to use the role manager feature. There is a corresponding HTTP module for that (RoleManagerModule) that handles PostAuthenticateRequest. Does this collide with the above combinations? No it doesn’t! When the WS-Fed module turns existing principals into a ClaimsPrincipal (like it did with the FormsIdentity), it also checks for RolePrincipal (which is the principal type created by role manager), and turns the roles in role claims. Nice! But as you can see in the last scenario above, this might result in unnecessary work, so I would rather recommend consolidating all role work (and other claims transformations) into the ClaimsAuthenticationManager. In there you can check for the authentication type of the incoming principal and act accordingly. HTH

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  • C Minishell Command Expansion Printing Gibberish

    - by Optimus_Pwn
    I'm writing a unix minishell in C, and am at the point where I'm adding command expansion. What I mean by this is that I can nest commands in other commands, for example: $> echo hello $(echo world! ... $(echo and stuff)) hello world! ... and stuff I think I have it working mostly, however it isn't marking the end of the expanded string correctly, for example if I do: $> echo a $(echo b $(echo c)) a b c $> echo d $(echo e) d e c See it prints the c, even though I didn't ask it to. Here is my code: msh.c - http://pastebin.com/sd6DZYwB expand.c - http://pastebin.com/uLqvFGPw I have a more code, but there's a lot of it, and these are the parts that I'm having trouble with at the moment. I'll try to tell you the basic way I'm doing this. Main is in msh.c, here it gets a line of input from either the commandline or a shellfile, and then calls processline (char *line, int outFD, int waitFlag), where line is the line we just got, outFD is the file descriptor of the output file, and waitFlag tells us whether or not we should wait if we fork. When we call this from main we do it like this: processline (buffer, 1, 1); In processline, we allocate a new line: char expanded_line[EXPANDEDLEN]; We then call expand, in expand.c: expand(line, expanded_line, EXPANDEDLEN); In expand, we copy the characters literally from line to expanded_line until we find a $(, which then calls: static int expCmdOutput(char *orig, char *new, int *oldl_ind, int *newl_ind) orig is line, and new is expanded line. oldl_ind and newl_ind are the current positions in the line and expanded line, respectively. Then we pipe, and recursively call processline, passing it the nested command(for example, if we had "echo a $(echo b)", we would pass processline "echo b"). This is where I get confused, each time expand is called, is it allocating a new chunk of memory EXPANDEDLEN long? If so, this is bad because I'll run out of stack room really quickly(in the case of a hugely nested commandline input). In expand I insert a null character at the end of the expanded string, so why is it printing past it? If you guys need any more code, or explanations, just ask. Secondly, I put the code in pastebin because there's a ton of it, and in my experience people don't like it when I fill up several pages with code. Thanks.

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  • How do i play nicely with MS SQL/SQL Server 2008

    - by acidzombie24
    Big problem. I have nearly given up. I am trying to port my prototype to use MS SQL so it will work on a server once i get it (the server will be SQL Server 2008, shared, i dont know any more info). So i tried to connect to SQL Server via visual studios IDE and had no luck. I enabled TCP and named pipes and restarted the service (and computer) with still no luck. I remembered about mdf files so i made that after an obstacle of not being able to make the connect string require i figure out visual studio has it in its properties and successfully connected with that. Then i had a problem with nested transactions. After not being able to figure out how to check i wondered if i can configure it to allow it somehow. I always thought all of MS were the same except for limitations but sql server seems to support nested transactions so theres no point trying to work around the problem with .mdf files since i wont need them and really just used it to port the base of my sql code and to check if syntax is correct. I tried installing SQL Server Management Studio since people mentioned it several times (as a solution or at least help). When installing it on windows 7 it says it may not be compatible. After running it, it launched SQL Server Installation Center (64-bit) which doesnt seem to be the same thing as i dont see a way to modify any of my server (networking) configurations or edit user permissions, etc. I am clueless what to do next. Does anyone have any ideas? I'm posting here bc i think my problem is more configurations and sql server then programming.

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  • Stored Procedures with SSRS? Hmm… not so much

    - by Rob Farley
    Little Bobby Tables’ mother says you should always sanitise your data input. Except that I think she’s wrong. The SQL Injection aspect is for another post, where I’ll show you why I think SQL Injection is the same kind of attack as many other attacks, such as the old buffer overflow, but here I want to have a bit of a whinge about the way that some people sanitise data input, and even have a whinge about people who insist on using stored procedures for SSRS reports. Let me say that again, in case you missed it the first time: I want to have a whinge about people who insist on using stored procedures for SSRS reports. Let’s look at the data input sanitisation aspect – except that I’m going to call it ‘parameter validation’. I’m talking about code that looks like this: create procedure dbo.GetMonthSummaryPerSalesPerson(@eomdate datetime) as begin     /* First check that @eomdate is a valid date */     if isdate(@eomdate) != 1     begin         select 'Please enter a valid date' as ErrorMessage;         return;     end     /* Then check that time has passed since @eomdate */     if datediff(day,@eomdate,sysdatetime()) < 5     begin         select 'Sorry - EOM is not complete yet' as ErrorMessage;         return;     end         /* If those checks have succeeded, return the data */     select SalesPersonID, count(*) as NumSales, sum(TotalDue) as TotalSales     from Sales.SalesOrderHeader     where OrderDate >= dateadd(month,-1,@eomdate)         and OrderDate < @eomdate     group by SalesPersonID     order by SalesPersonID; end Notice that the code checks that a date has been entered. Seriously??!! This must only be to check for NULL values being passed in, because anything else would have to be a valid datetime to avoid an error. The other check is maybe fair enough, but I still don’t like it. The two problems I have with this stored procedure are the result sets and the small fact that the stored procedure even exists in the first place. But let’s consider the first one of these problems for starters. I’ll get to the second one in a moment. If you read Jes Borland (@grrl_geek)’s recent post about returning multiple result sets in Reporting Services, you’ll be aware that Reporting Services doesn’t support multiple results sets from a single query. And when it says ‘single query’, it includes ‘stored procedure call’. It’ll only handle the first result set that comes back. But that’s okay – we have RETURN statements, so our stored procedure will only ever return a single result set.  Sometimes that result set might contain a single field called ErrorMessage, but it’s still only one result set. Except that it’s not okay, because Reporting Services needs to know what fields to expect. Your report needs to hook into your fields, so SSRS needs to have a way to get that information. For stored procs, it uses an option called FMTONLY. When Reporting Services tries to figure out what fields are going to be returned by a query (or stored procedure call), it doesn’t want to have to run the whole thing. That could take ages. (Maybe it’s seen some of the stored procedures I’ve had to deal with over the years!) So it turns on FMTONLY before it makes the call (and turns it off again afterwards). FMTONLY is designed to be able to figure out the shape of the output, without actually running the contents. It’s very useful, you might think. set fmtonly on exec dbo.GetMonthSummaryPerSalesPerson '20030401'; set fmtonly off Without the FMTONLY lines, this stored procedure returns a result set that has three columns and fourteen rows. But with FMTONLY turned on, those rows don’t come back. But what I do get back hurts Reporting Services. It doesn’t run the stored procedure at all. It just looks for anything that could be returned and pushes out a result set in that shape. Despite the fact that I’ve made sure that the logic will only ever return a single result set, the FMTONLY option kills me by returning three of them. It would have been much better to push these checks down into the query itself. alter procedure dbo.GetMonthSummaryPerSalesPerson(@eomdate datetime) as begin     select SalesPersonID, count(*) as NumSales, sum(TotalDue) as TotalSales     from Sales.SalesOrderHeader     where     /* Make sure that @eomdate is valid */         isdate(@eomdate) = 1     /* And that it's sufficiently past */     and datediff(day,@eomdate,sysdatetime()) >= 5     /* And now use it in the filter as appropriate */     and OrderDate >= dateadd(month,-1,@eomdate)     and OrderDate < @eomdate     group by SalesPersonID     order by SalesPersonID; end Now if we run it with FMTONLY turned on, we get the single result set back. But let’s consider the execution plan when we pass in an invalid date. First let’s look at one that returns data. I’ve got a semi-useful index in place on OrderDate, which includes the SalesPersonID and TotalDue fields. It does the job, despite a hefty Sort operation. …compared to one that uses a future date: You might notice that the estimated costs are similar – the Index Seek is still 28%, the Sort is still 71%. But the size of that arrow coming out of the Index Seek is a whole bunch smaller. The coolest thing here is what’s going on with that Index Seek. Let’s look at some of the properties of it. Glance down it with me… Estimated CPU cost of 0.0005728, 387 estimated rows, estimated subtree cost of 0.0044385, ForceSeek false, Number of Executions 0. That’s right – it doesn’t run. So much for reading plans right-to-left... The key is the Filter on the left of it. It has a Startup Expression Predicate in it, which means that it doesn’t call anything further down the plan (to the right) if the predicate evaluates to false. Using this method, we can make sure that our stored procedure contains a single query, and therefore avoid any problems with multiple result sets. If we wanted, we could always use UNION ALL to make sure that we can return an appropriate error message. alter procedure dbo.GetMonthSummaryPerSalesPerson(@eomdate datetime) as begin     select SalesPersonID, count(*) as NumSales, sum(TotalDue) as TotalSales, /*Placeholder: */ '' as ErrorMessage     from Sales.SalesOrderHeader     where     /* Make sure that @eomdate is valid */         isdate(@eomdate) = 1     /* And that it's sufficiently past */     and datediff(day,@eomdate,sysdatetime()) >= 5     /* And now use it in the filter as appropriate */     and OrderDate >= dateadd(month,-1,@eomdate)     and OrderDate < @eomdate     group by SalesPersonID     /* Now include the error messages */     union all     select 0, 0, 0, 'Please enter a valid date' as ErrorMessage     where isdate(@eomdate) != 1     union all     select 0, 0, 0, 'Sorry - EOM is not complete yet' as ErrorMessage     where datediff(day,@eomdate,sysdatetime()) < 5     order by SalesPersonID; end But still I don’t like it, because it’s now a stored procedure with a single query. And I don’t like stored procedures that should be functions. That’s right – I think this should be a function, and SSRS should call the function. And I apologise to those of you who are now planning a bonfire for me. Guy Fawkes’ night has already passed this year, so I think you miss out. (And I’m not going to remind you about when the PASS Summit is in 2012.) create function dbo.GetMonthSummaryPerSalesPerson(@eomdate datetime) returns table as return (     select SalesPersonID, count(*) as NumSales, sum(TotalDue) as TotalSales, '' as ErrorMessage     from Sales.SalesOrderHeader     where     /* Make sure that @eomdate is valid */         isdate(@eomdate) = 1     /* And that it's sufficiently past */     and datediff(day,@eomdate,sysdatetime()) >= 5     /* And now use it in the filter as appropriate */     and OrderDate >= dateadd(month,-1,@eomdate)     and OrderDate < @eomdate     group by SalesPersonID     union all     select 0, 0, 0, 'Please enter a valid date' as ErrorMessage     where isdate(@eomdate) != 1     union all     select 0, 0, 0, 'Sorry - EOM is not complete yet' as ErrorMessage     where datediff(day,@eomdate,sysdatetime()) < 5 ); We’ve had to lose the ORDER BY – but that’s fine, as that’s a client thing anyway. We can have our reports leverage this stored query still, but we’re recognising that it’s a query, not a procedure. A procedure is designed to DO stuff, not just return data. We even get entries in sys.columns that confirm what the shape of the result set actually is, which makes sense, because a table-valued function is the right mechanism to return data. And we get so much more flexibility with this. If you haven’t seen the simplification stuff that I’ve preached on before, jump over to http://bit.ly/SimpleRob and watch the video of when I broke a microphone and nearly fell off the stage in Wales. You’ll see the impact of being able to have a simplifiable query. You can also read the procedural functions post I wrote recently, if you didn’t follow the link from a few paragraphs ago. So if we want the list of SalesPeople that made any kind of sales in a given month, we can do something like: select SalesPersonID from dbo.GetMonthSummaryPerSalesPerson(@eomonth) order by SalesPersonID; This doesn’t need to look up the TotalDue field, which makes a simpler plan. select * from dbo.GetMonthSummaryPerSalesPerson(@eomonth) where SalesPersonID is not null order by SalesPersonID; This one can avoid having to do the work on the rows that don’t have a SalesPersonID value, pushing the predicate into the Index Seek rather than filtering the results that come back to the report. If we had joins involved, we might see some of those being simplified out. We also get the ability to include query hints in individual reports. We shift from having a single-use stored procedure to having a reusable stored query – and isn’t that one of the main points of modularisation? Stored procedures in Reporting Services are just a bit limited for my liking. They’re useful in plenty of ways, but if you insist on using stored procedures all the time rather that queries that use functions – that’s rubbish. @rob_farley

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  • How I can add JScroll bar to NavigableImagePanel which is an Image panel with an small navigation vi

    - by Sarah Kho
    Hi, I have the following NavigableImagePanel, it is under BSD license and I found it in the web. What I want to do with this panel is as follow: I want to add a JScrollPane to it in order to show images in their full size and let the users to re-center the image using the small navigation panel. Right now, the panel resize the images to fit them in the current panel size. I want it to load the image in its real size and let users to navigate to different parts of the image using the navigation panel. Source code for the panel: import java.awt.AWTEvent; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GraphicsEnvironment; import java.awt.Image; import java.awt.Point; import java.awt.Rectangle; import java.awt.RenderingHints; import java.awt.Toolkit; import java.awt.event.ComponentAdapter; import java.awt.event.ComponentEvent; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionListener; import java.awt.event.MouseWheelEvent; import java.awt.event.MouseWheelListener; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.Arrays; import javax.imageio.ImageIO; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.SwingUtilities; /** * @author pxt * */ public class NavigableImagePanel extends JPanel { /** * <p>Identifies a change to the zoom level.</p> */ public static final String ZOOM_LEVEL_CHANGED_PROPERTY = "zoomLevel"; /** * <p>Identifies a change to the zoom increment.</p> */ public static final String ZOOM_INCREMENT_CHANGED_PROPERTY = "zoomIncrement"; /** * <p>Identifies that the image in the panel has changed.</p> */ public static final String IMAGE_CHANGED_PROPERTY = "image"; private static final double SCREEN_NAV_IMAGE_FACTOR = 0.15; // 15% of panel's width private static final double NAV_IMAGE_FACTOR = 0.3; // 30% of panel's width private static final double HIGH_QUALITY_RENDERING_SCALE_THRESHOLD = 1.0; private static final Object INTERPOLATION_TYPE = RenderingHints.VALUE_INTERPOLATION_BILINEAR; private double zoomIncrement = 0.2; private double zoomFactor = 1.0 + zoomIncrement; private double navZoomFactor = 1.0 + zoomIncrement; private BufferedImage image; private BufferedImage navigationImage; private int navImageWidth; private int navImageHeight; private double initialScale = 0.0; private double scale = 0.0; private double navScale = 0.0; private int originX = 0; private int originY = 0; private Point mousePosition; private Dimension previousPanelSize; private boolean navigationImageEnabled = true; private boolean highQualityRenderingEnabled = true; private WheelZoomDevice wheelZoomDevice = null; private ButtonZoomDevice buttonZoomDevice = null; /** * <p>Defines zoom devices.</p> */ public static class ZoomDevice { /** * <p>Identifies that the panel does not implement zooming, * but the component using the panel does (programmatic zooming method).</p> */ public static final ZoomDevice NONE = new ZoomDevice("none"); /** * <p>Identifies the left and right mouse buttons as the zooming device.</p> */ public static final ZoomDevice MOUSE_BUTTON = new ZoomDevice("mouseButton"); /** * <p>Identifies the mouse scroll wheel as the zooming device.</p> */ public static final ZoomDevice MOUSE_WHEEL = new ZoomDevice("mouseWheel"); private String zoomDevice; private ZoomDevice(String zoomDevice) { this.zoomDevice = zoomDevice; } public String toString() { return zoomDevice; } } //This class is required for high precision image coordinates translation. private class Coords { public double x; public double y; public Coords(double x, double y) { this.x = x; this.y = y; } public int getIntX() { return (int)Math.round(x); } public int getIntY() { return (int)Math.round(y); } public String toString() { return "[Coords: x=" + x + ",y=" + y + "]"; } } private class WheelZoomDevice implements MouseWheelListener { public void mouseWheelMoved(MouseWheelEvent e) { Point p = e.getPoint(); boolean zoomIn = (e.getWheelRotation() < 0); if (isInNavigationImage(p)) { if (zoomIn) { navZoomFactor = 1.0 + zoomIncrement; } else { navZoomFactor = 1.0 - zoomIncrement; } zoomNavigationImage(); } else if (isInImage(p)) { if (zoomIn) { zoomFactor = 1.0 + zoomIncrement; } else { zoomFactor = 1.0 - zoomIncrement; } zoomImage(); } } } private class ButtonZoomDevice extends MouseAdapter { public void mouseClicked(MouseEvent e) { Point p = e.getPoint(); if (SwingUtilities.isRightMouseButton(e)) { if (isInNavigationImage(p)) { navZoomFactor = 1.0 - zoomIncrement; zoomNavigationImage(); } else if (isInImage(p)) { zoomFactor = 1.0 - zoomIncrement; zoomImage(); } } else { if (isInNavigationImage(p)) { navZoomFactor = 1.0 + zoomIncrement; zoomNavigationImage(); } else if (isInImage(p)) { zoomFactor = 1.0 + zoomIncrement; zoomImage(); } } } } /** * <p>Creates a new navigable image panel with no default image and * the mouse scroll wheel as the zooming device.</p> */ public NavigableImagePanel() { setOpaque(false); addComponentListener(new ComponentAdapter() { public void componentResized(ComponentEvent e) { if (scale > 0.0) { if (isFullImageInPanel()) { centerImage(); } else if (isImageEdgeInPanel()) { scaleOrigin(); } if (isNavigationImageEnabled()) { createNavigationImage(); } repaint(); } previousPanelSize = getSize(); } }); addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e)) { if (isInNavigationImage(e.getPoint())) { Point p = e.getPoint(); displayImageAt(p); } } } public void mouseClicked(MouseEvent e){ if (e.getClickCount() == 2) { resetImage(); } } }); addMouseMotionListener(new MouseMotionListener() { public void mouseDragged(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e) && !isInNavigationImage(e.getPoint())) { Point p = e.getPoint(); moveImage(p); } } public void mouseMoved(MouseEvent e) { //we need the mouse position so that after zooming //that position of the image is maintained mousePosition = e.getPoint(); } }); setZoomDevice(ZoomDevice.MOUSE_WHEEL); } /** * <p>Creates a new navigable image panel with the specified image * and the mouse scroll wheel as the zooming device.</p> */ public NavigableImagePanel(BufferedImage image) throws IOException { this(); setImage(image); } private void addWheelZoomDevice() { if (wheelZoomDevice == null) { wheelZoomDevice = new WheelZoomDevice(); addMouseWheelListener(wheelZoomDevice); } } private void addButtonZoomDevice() { if (buttonZoomDevice == null) { buttonZoomDevice = new ButtonZoomDevice(); addMouseListener(buttonZoomDevice); } } private void removeWheelZoomDevice() { if (wheelZoomDevice != null) { removeMouseWheelListener(wheelZoomDevice); wheelZoomDevice = null; } } private void removeButtonZoomDevice() { if (buttonZoomDevice != null) { removeMouseListener(buttonZoomDevice); buttonZoomDevice = null; } } /** * <p>Sets a new zoom device.</p> * * @param newZoomDevice specifies the type of a new zoom device. */ public void setZoomDevice(ZoomDevice newZoomDevice) { if (newZoomDevice == ZoomDevice.NONE) { removeWheelZoomDevice(); removeButtonZoomDevice(); } else if (newZoomDevice == ZoomDevice.MOUSE_BUTTON) { removeWheelZoomDevice(); addButtonZoomDevice(); } else if (newZoomDevice == ZoomDevice.MOUSE_WHEEL) { removeButtonZoomDevice(); addWheelZoomDevice(); } } /** * <p>Gets the current zoom device.</p> */ public ZoomDevice getZoomDevice() { if (buttonZoomDevice != null) { return ZoomDevice.MOUSE_BUTTON; } else if (wheelZoomDevice != null) { return ZoomDevice.MOUSE_WHEEL; } else { return ZoomDevice.NONE; } } //Called from paintComponent() when a new image is set. private void initializeParams() { double xScale = (double)getWidth() / image.getWidth(); double yScale = (double)getHeight() / image.getHeight(); initialScale = Math.min(xScale, yScale); scale = initialScale; //An image is initially centered centerImage(); if (isNavigationImageEnabled()) { createNavigationImage(); } } //Centers the current image in the panel. private void centerImage() { originX = (int)(getWidth() - getScreenImageWidth()) / 2; originY = (int)(getHeight() - getScreenImageHeight()) / 2; } //Creates and renders the navigation image in the upper let corner of the panel. private void createNavigationImage() { //We keep the original navigation image larger than initially //displayed to allow for zooming into it without pixellation effect. navImageWidth = (int)(getWidth() * NAV_IMAGE_FACTOR); navImageHeight = navImageWidth * image.getHeight() / image.getWidth(); int scrNavImageWidth = (int)(getWidth() * SCREEN_NAV_IMAGE_FACTOR); int scrNavImageHeight = scrNavImageWidth * image.getHeight() / image.getWidth(); navScale = (double)scrNavImageWidth / navImageWidth; navigationImage = new BufferedImage(navImageWidth, navImageHeight, image.getType()); Graphics g = navigationImage.getGraphics(); g.drawImage(image, 0, 0, navImageWidth, navImageHeight, null); } /** * <p>Sets an image for display in the panel.</p> * * @param image an image to be set in the panel */ public void setImage(BufferedImage image) { BufferedImage oldImage = this.image; this.image = image; //Reset scale so that initializeParameters() is called in paintComponent() //for the new image. scale = 0.0; firePropertyChange(IMAGE_CHANGED_PROPERTY, (Image)oldImage, (Image)image); repaint(); } /** * <p>resets an image to the centre of the panel</p> * */ public void resetImage() { BufferedImage oldImage = this.image; this.image = image; //Reset scale so that initializeParameters() is called in paintComponent() //for the new image. scale = 0.0; firePropertyChange(IMAGE_CHANGED_PROPERTY, (Image)oldImage, (Image)image); repaint(); } /** * <p>Tests whether an image uses the standard RGB color space.</p> */ public static boolean isStandardRGBImage(BufferedImage bImage) { return bImage.getColorModel().getColorSpace().isCS_sRGB(); } //Converts this panel's coordinates into the original image coordinates private Coords panelToImageCoords(Point p) { return new Coords((p.x - originX) / scale, (p.y - originY) / scale); } //Converts the original image coordinates into this panel's coordinates private Coords imageToPanelCoords(Coords p) { return new Coords((p.x * scale) + originX, (p.y * scale) + originY); } //Converts the navigation image coordinates into the zoomed image coordinates private Point navToZoomedImageCoords(Point p) { int x = p.x * getScreenImageWidth() / getScreenNavImageWidth(); int y = p.y * getScreenImageHeight() / getScreenNavImageHeight(); return new Point(x, y); } //The user clicked within the navigation image and this part of the image //is displayed in the panel. //The clicked point of the image is centered in the panel. private void displayImageAt(Point p) { Point scrImagePoint = navToZoomedImageCoords(p); originX = -(scrImagePoint.x - getWidth() / 2); originY = -(scrImagePoint.y - getHeight() / 2); repaint(); } //Tests whether a given point in the panel falls within the image boundaries. private boolean isInImage(Point p) { Coords coords = panelToImageCoords(p); int x = coords.getIntX(); int y = coords.getIntY(); return (x >= 0 && x < image.getWidth() && y >= 0 && y < image.getHeight()); } //Tests whether a given point in the panel falls within the navigation image //boundaries. private boolean isInNavigationImage(Point p) { return (isNavigationImageEnabled() && p.x < getScreenNavImageWidth() && p.y < getScreenNavImageHeight()); } //Used when the image is resized. private boolean isImageEdgeInPanel() { if (previousPanelSize == null) { return false; } return (originX > 0 && originX < previousPanelSize.width || originY > 0 && originY < previousPanelSize.height); } //Tests whether the image is displayed in its entirety in the panel. private boolean isFullImageInPanel() { return (originX >= 0 && (originX + getScreenImageWidth()) < getWidth() && originY >= 0 && (originY + getScreenImageHeight()) < getHeight()); } /** * <p>Indicates whether the high quality rendering feature is enabled.</p> * * @return true if high quality rendering is enabled, false otherwise. */ public boolean isHighQualityRenderingEnabled() { return highQualityRenderingEnabled; } /** * <p>Enables/disables high quality rendering.</p> * * @param enabled enables/disables high quality rendering */ public void setHighQualityRenderingEnabled(boolean enabled) { highQualityRenderingEnabled = enabled; } //High quality rendering kicks in when when a scaled image is larger //than the original image. In other words, //when image decimation stops and interpolation starts. private boolean isHighQualityRendering() { return (highQualityRenderingEnabled && scale > HIGH_QUALITY_RENDERING_SCALE_THRESHOLD); } /** * <p>Indicates whether navigation image is enabled.<p> * * @return true when navigation image is enabled, false otherwise. */ public boolean isNavigationImageEnabled() { return navigationImageEnabled; } /** * <p>Enables/disables navigation with the navigation image.</p> * <p>Navigation image should be disabled when custom, programmatic navigation * is implemented.</p> * * @param enabled true when navigation image is enabled, false otherwise. */ public void setNavigationImageEnabled(boolean enabled) { navigationImageEnabled = enabled; repaint(); } //Used when the panel is resized private void scaleOrigin() { originX = originX * getWidth() / previousPanelSize.width; originY = originY * getHeight() / previousPanelSize.height; repaint(); } //Converts the specified zoom level to scale. private double zoomToScale(double zoom) { return initialScale * zoom; } /** * <p>Gets the current zoom level.</p> * * @return the current zoom level */ public double getZoom() { return scale / initialScale; } /** * <p>Sets the zoom level used to display the image.</p> * <p>This method is used in programmatic zooming. The zooming center is * the point of the image closest to the center of the panel. * After a new zoom level is set the image is repainted.</p> * * @param newZoom the zoom level used to display this panel's image. */ public void setZoom(double newZoom) { Point zoomingCenter = new Point(getWidth() / 2, getHeight() / 2); setZoom(newZoom, zoomingCenter); } /** * <p>Sets the zoom level used to display the image, and the zooming center, * around which zooming is done.</p> * <p>This method is used in programmatic zooming. * After a new zoom level is set the image is repainted.</p> * * @param newZoom the zoom level used to display this panel's image. */ public void setZoom(double newZoom, Point zoomingCenter) { Coords imageP = panelToImageCoords(zoomingCenter); if (imageP.x < 0.0) { imageP.x = 0.0; } if (imageP.y < 0.0) { imageP.y = 0.0; } if (imageP.x >= image.getWidth()) { imageP.x = image.getWidth() - 1.0; } if (imageP.y >= image.getHeight()) { imageP.y = image.getHeight() - 1.0; } Coords correctedP = imageToPanelCoords(imageP); double oldZoom = getZoom(); scale = zoomToScale(newZoom); Coords panelP = imageToPanelCoords(imageP); originX += (correctedP.getIntX() - (int)panelP.x); originY += (correctedP.getIntY() - (int)panelP.y); firePropertyChange(ZOOM_LEVEL_CHANGED_PROPERTY, new Double(oldZoom), new Double(getZoom())); repaint(); } /** * <p>Gets the current zoom increment.</p> * * @return the current zoom increment */ public double getZoomIncrement() { return zoomIncrement; } /** * <p>Sets a new zoom increment value.</p> * * @param newZoomIncrement new zoom increment value */ public void setZoomIncrement(double newZoomIncrement) { double oldZoomIncrement = zoomIncrement; zoomIncrement = newZoomIncrement; firePropertyChange(ZOOM_INCREMENT_CHANGED_PROPERTY, new Double(oldZoomIncrement), new Double(zoomIncrement)); } //Zooms an image in the panel by repainting it at the new zoom level. //The current mouse position is the zooming center. private void zoomImage() { Coords imageP = panelToImageCoords(mousePosition); double oldZoom = getZoom(); scale *= zoomFactor; Coords panelP = imageToPanelCoords(imageP); originX += (mousePosition.x - (int)panelP.x); originY += (mousePosition.y - (int)panelP.y); firePropertyChange(ZOOM_LEVEL_CHANGED_PROPERTY, new Double(oldZoom), new Double(getZoom())); repaint(); } //Zooms the navigation image private void zoomNavigationImage() { navScale *= navZoomFactor; repaint(); } /** * <p>Gets the image origin.</p> * <p>Image origin is defined as the upper, left corner of the image in * the panel's coordinate system.</p> * @return the point of the upper, left corner of the image in the panel's coordinates * system. */ public Point getImageOrigin() { return new Point(originX, originY); } /** * <p>Sets the image origin.</p> * <p>Image origin is defined as the upper, left corner of the image in * the panel's coordinate system. After a new origin is set, the image is repainted. * This method is used for programmatic image navigation.</p>

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  • Code golf: find all anagrams

    - by Charles Ma
    An word is an anagram if the letters in that word can be re-arranged to form a different word. Task: Find all sets of anagrams given a word list Input: a list of words from stdin with each word separated by a new line e.g. A A's AOL AOL's Aachen Aachen's Aaliyah Aaliyah's Aaron Aaron's Abbas Abbasid Abbasid's Output: All sets of anagrams, with each set separated by a separate line Example run: ./anagram < words marcos caroms macros lump's plum's dewar's wader's postman tampons dent tend macho mocha stoker's stroke's hops posh shop chasity scythia ... I have a 149 char perl solution which I'll post as soon as a few more people post :) Have fun!

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  • Sentiment analysis with NLTK python for sentences using sample data or webservice?

    - by Ke
    I am embarking upon a NLP project for sentiment analysis. I have successfully installed NLTK for python (seems like a great piece of software for this). However,I am having trouble understanding how it can be used to accomplish my task. Here is my task: I start with one long piece of data (lets say several hundred tweets on the subject of the UK election from their webservice) I would like to break this up into sentences (or info no longer than 100 or so chars) (I guess i can just do this in python??) Then to search through all the sentences for specific instances within that sentence e.g. "David Cameron" Then I would like to check for positive/negative sentiment in each sentence and count them accordingly NB: I am not really worried too much about accuracy because my data sets are large and also not worried too much about sarcasm. Here are the troubles I am having: All the data sets I can find e.g. the corpus movie review data that comes with NLTK arent in webservice format. It looks like this has had some processing done already. As far as I can see the processing (by stanford) was done with WEKA. Is it not possible for NLTK to do all this on its own? Here all the data sets have already been organised into positive/negative already e.g. polarity dataset http://www.cs.cornell.edu/People/pabo/movie-review-data/ How is this done? (to organise the sentences by sentiment, is it definitely WEKA? or something else?) I am not sure I understand why WEKA and NLTK would be used together. Seems like they do much the same thing. If im processing the data with WEKA first to find sentiment why would I need NLTK? Is it possible to explain why this might be necessary? I have found a few scripts that get somewhat near this task, but all are using the same pre-processed data. Is it not possible to process this data myself to find sentiment in sentences rather than using the data samples given in the link? Any help is much appreciated and will save me much hair! Cheers Ke

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  • How do I determine a best-fit distribution in java?

    - by Eadwacer
    I have a bunch of sets of data (between 50 to 500 points, each of which can take a positive integral value) and need to determine which distribution best describes them. I have done this manually for several of them, but need to automate this going forward. Some of the sets are completely modal (every datum has the value of 15), some are strongly modal or bimodal, some are bell-curves (often skewed and with differing degrees of kertosis/pointiness), some are roughly flat, and there are any number of other possible distributions (possion, power-law, etc.). I need a way to determine which distribution best describes the data and (ideally) also provides me with a fitness metric so that I know how confident I am in the analysis. Existing open-source libraries would be ideal, followed by well documented algorithms that I can implement myself.

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  • How do I prevent the concurrent execution of a javascript function?

    - by RyanV
    I am making a ticker similar to the "From the AP" one at The Huffington Post, using jQuery. The ticker rotates through a ul, either by user command (clicking an arrow) or by an auto-scroll. Each list-item is display:none by default. It is revealed by the addition of a "showHeadline" class which is display:list-item. HTML for the UL Looks like this: <ul class="news" id="news"> <li class="tickerTitle showHeadline">Test Entry</li> <li class="tickerTitle">Test Entry2</li> <li class="tickerTitle">Test Entry3</li> </ul> When the user clicks the right arrow, or the auto-scroll setTimeout goes off, it runs a tickForward() function: function tickForward(){ var $active = $('#news li.showHeadline'); var $next = $active.next(); if($next.length==0) $next = $('#news li:first'); $active.stop(true, true); $active.fadeOut('slow', function() {$active.removeClass('showHeadline');}); setTimeout(function(){$next.fadeIn('slow', function(){$next.addClass('showHeadline');})}, 1000); if(isPaused == true){ } else{ startScroll() } }; This is heavily inspired by Jon Raasch's A Simple jQuery Slideshow. Basically, find what's visible, what should be visible next, make the visible thing fade and remove the class that marks it as visible, then fade in the next thing and add the class that makes it visible. Now, everything is hunky-dory if the auto-scroll is running, kicking off tickForward() once every three seconds. But if the user clicks the arrow button repeatedly, it creates two negative conditions: Rather than advance quickly through the list for just the number of clicks made, it continues scrolling at a faster-than-normal rate indefinitely. It can produce a situation where two (or more) list items are given the .showHeadline class, so there's overlap on the list. I can see these happening (especially #2) because the tickForward() function can run concurrently with itself, producing different sets of $active and $next. So I think my question is: What would be the best way to prevent concurrent execution of the tickForward() method? Some things I have tried or considered: Setting a Flag: When tickForward() runs, it sets an isRunning flag to true, and sets it back to false right before it ends. The logic for the event handler is set to only call tickForward() if isRunning is false. I tried a simple implementation of this, and isRunning never appeared to be changed. The jQuery queue(): I think it would be useful to queue up the tickForward() commands, so if you clicked it five times quickly, it would still run as commanded but wouldn't run concurrently. However, in my cursory reading on the subject, it appears that a queue has to be attached to the object its queue applies to, and since my tickForward() method affects multiple lis, I don't know where I'd attach it.

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  • How to spread changes in oriented graph?

    - by joseph
    Hello. I have oriented graph. Graph can be strongly connected. Every vertix can have a set of anything, for example letters. The set is user editable. Every vertix makes intersection of sets in previous vertices (only one step back). But now, there is problem: When I update set of one vertex, the change should expand to all vertices and uptate their intersection of sets of previous vertices. How to do every vertex have correct intersection after update of any vertex? Restriction: algorithm must avoid to stick in infinity. Any idea how to solve it?

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  • Null Pointer Exception on a 2D array (Java)

    - by user315156
    I have a class, "Tetris", in which one of the instance variables is "board". "board" is 2D array of Color objects. Upon the creation of a tetris object I call a method that sets the dimensions of board and then sets all of the Color objects to be the Default value, that is to say, Color.blue. public Tetris(int rows, int cols){ this.rows = rows; this.cols = cols; reset(rows, cols); } public void reset(int rows, int cols){ Color[][] board = new Color[rows][cols]; for(int i = 0; i Unfortunately, when I run the code (which obviously has not been posted in its entirety) I get a null pointer exception on the line: board[i][j] = DEFAULT_COLOR; // Color.blue; //DEFAULT-COLOR. Is there anything obviously wrong with what I am doing? (Sorry if there are glaring format issues, this is my first time on Stack Overflow)

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  • Deriving arrays in mathematics

    - by Gio Borje
    So I found some similarities between arrays and set notation while learning about sets and sequences in precalc e.g. set notation: {a | cond } = { a1, a2, a3, a4, ..., an} given that n is the domain (or index) of the array, a subset of Natural numbers (or unsigned integer). Most programming languages would provide similar methods to arrays that are applied to sets e.g. upperbounds & lowerbounds; possibly suprema and infima too. Where did arrays come from?

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  • fuzzy implementaion for capture specific strings

    - by kasun-456
    I am going to develop a web crawler using java to capture hotel room prices from hotel websites. In this case i want to capture room price with the room type and the meal type, so my algorithm should intelligent for that. as an example: Room type: Delux Meal type: HalfBoad price : $20.00 The main problem is room prices can be in different different ways in different different hotel sites. so my algorithm should independent from hotel sites. I am plan to use above room types and meal types as a fuzzy sets and compare the words in webpage with above fuzzy sets using a suitable membership function. any one experienced with this??? or have an Idea for my problem??

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  • SelectedIndex of combobox not updating correctly using databinding.

    - by Matthijs Wessels
    I have a ComboBox: <ComboBox Name="iComponentFieldComboBox" SelectedIndex="{Binding ComponentFieldSelectedIndex, Mode=TwoWay}" Height="23" Margin="132,0,280,38" VerticalAlignment="Bottom"> <ComboBoxItem Name="item1">item1</ComboBoxItem> <ComboBoxItem Name="item2">item2</ComboBoxItem> <ComboBoxItem Name="item3">item3</ComboBoxItem> </ComboBox> When I start my WPF and set the ComponentFieldSelectedIndex property of my ViewModel in my code, nothing happens. But after I have selected an item in the combobox, then suddenly setting ComponentFieldSelectedIndex does work. for example: start app. click button that sets ComponentFieldSelectedIndex to 1. selected item doesn't change to item2. select item3 in combo box. click button that sets ComponentFieldSelectedIndex to 1. selected item does change to item2. Does anyone have an idea what could be causing this?

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  • c# and linq: want {1,1,2,3} == {1,2,3,1} returns true but {1,1,2,3} == {1,2,3} returns false

    - by dFlat
    I have two sets, both IEnumerables, and I want to compare them. string[] names1 = { "tom", "dick", "harry" }; string[] names2 = { "tom", "dick", "harry", "harry"}; string[] names3 = { "tom", "dick", "harry", "sally" }; string[] names4 = { "dick", "harry", "tom" }; Want names1 == names4 to return true (and self == self returns true obviously) But all other combos return false. What is the most efficient way? These can be large sets of complex objects. I looked at doing: var a = name1.orderby<MyCustomType, string>(v => v.Name); var b = name4.orderby<MyCustomType, string>(v => v.Name); return a == b;

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  • Combine 2 apps into one DB?

    - by coffeeaddict
    I'm debating whether to use the same DB for both my blog and my wiki. Since both are open source, and both install the required tables which is a very small number of tables for both apps, I'm thinking about just using one database to represent both sets of tables. Is this common and safe to do? I am hesitant because I always create a new DB for every application I create or use. But in this case, I don't want to spend another $10 a month from my shared hosting just to get another SQL 2008 DB to host a wiki..it's small and I'm the only one using the wiki. I just want to point the wiki to my existing blog DB that's already running and have the wiki wizard auto gen the tables to that DB and just hold both sets of tables there.

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  • Evaluating points in time by months, but without referencing years in Rails

    - by MikeH
    FYI, There is some overlap in the initial description of this question with a question I asked yesterday, but the question is different. My app has users who have seasonal products. When a user selects a product, we allow him to also select the product's season. We accomplish this by letting him select a start date and an end date for each product. We're using date_select to generate two sets of drop-downs: one for the start date and one for the end date. Including years doesn't make sense for our model. So we're using the option: discard_year => true When you use discard_year => true, Rails sets a year in the database, it just doesn't appear in the views. Rails sets all the years to either 0001 or 0002 in our app. Yes, we could make it 2009 and 2010 or any other pair. But the point is that we want the months and days to function independent of a particular year. If we used 2009 and 2010, then those dates would be wrong next year because we don't expect these records to be updated every year. My problem is that we need to dynamically evaluate the availability of products based on their relationship to the current month. For example, assume it's March 15. Regardless of the year, I need a method that can tell me that a product available from October to January is not available right now. If we were using actual years, this would be pretty easy. For example, in the products model, I can do this: def is_available? (season_start.past? && season_end.future?) end I can also evaluate a start_date and an end_date against current_date However, in setup I've described above where we have arbitrary years that only make sense relative to each other, these methods don't work. For example, is_available? would return false for all my products because their end date is in the year 0001 or 0002. What I need is a method just like the ones I used as examples above, except that they evaluate against current_month instead of current_date, and past? and future months instead of years. I have no idea how to do this or whether Rails has any built in functionality that could help. I've gone through all the date and time methods/helpers in the API docs, but I'm not seeing anything equivalent to what I'm describing. Thanks.

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  • Permutations of Varying Size

    - by waiwai933
    I'm trying to write a function in PHP that gets all permutations of all possible sizes. I think an example would be the best way to start off: $my_array = array(1,1,2,3); Possible permutations of varying size: 1 1 // * See Note 2 3 1,1 1,2 1,3 // And so forth, for all the sets of size 2 1,1,2 1,1,3 1,2,1 // And so forth, for all the sets of size 3 1,1,2,3 1,1,3,2 // And so forth, for all the sets of size 4 Note: I don't care if there's a duplicate or not. For the purposes of this example, all future duplicates have been omitted. What I have so far in PHP: function getPermutations($my_array){ $permutation_length = 1; $keep_going = true; while($keep_going){ while($there_are_still_permutations_with_this_length){ // Generate the next permutation and return it into an array // Of course, the actual important part of the code is what I'm having trouble with. } $permutation_length++; if($permutation_length>count($my_array)){ $keep_going = false; } else{ $keep_going = true; } } return $return_array; } The closest thing I can think of is shuffling the array, picking the first n elements, seeing if it's already in the results array, and if it's not, add it in, and then stop when there are mathematically no more possible permutations for that length. But it's ugly and resource-inefficient. Any pseudocode algorithms would be greatly appreciated. Also, for super-duper (worthless) bonus points, is there a way to get just 1 permutation with the function but make it so that it doesn't have to recalculate all previous permutations to get the next? For example, I pass it a parameter 3, which means it's already done 3 permutations, and it just generates number 4 without redoing the previous 3? (Passing it the parameter is not necessary, it could keep track in a global or static). The reason I ask this is because as the array grows, so does the number of possible combinations. Suffice it to say that one small data set with only a dozen elements grows quickly into the trillions of possible combinations and I don't want to task PHP with holding trillions of permutations in its memory at once.

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  • C# Class Design Question

    - by Soo
    This is a super newbie question, I've been programming for a while, but am just learning OOP. I have a class that works with user input via the C# console. There are different methods in this class to gather different input sets. I have another class that takes these input sets and puts them in a database. What is the best way to pass the input from my input class to my database insert class? My guess would be: Array1[] = inputClass.GetParameterSet1(); DatabaseInsertClass.InsertIntoDatabase1(Array1[]); Is there anything wrong with this or is there a better way to do this? Should I even have two classes (The database class could also take the user input)?

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  • Illegal instruction in Assembly

    - by Natasha
    I really do not understand why this simple code works fine in the first attempt but when putting it in a procedure an error shows: NTVDM CPU has encountered an illegal instruction CS:db22 IP:4de4 OP:f0 ff ff ff ff The first code segment works just fine: .model small .stack 100h .code start: mov ax,@data mov ds,ax mov es,ax MOV AH,02H ;sets cursor up MOV BH,00H MOV DH,02 MOV DL,00 INT 10H EXIT: MOV AH,4CH INT 21H END However This generates an error: .model small .stack 100h .code start: mov ax,@data mov ds,ax mov es,ax call set_cursor PROC set_cursor near MOV AH,02H ;sets cursor up MOV BH,00H MOV DH,02 MOV DL,00 INT 10H RET set_cursor ENDP EXIT: MOV AH,4CH INT 21H END Note: Nothing is wrong with windows config. I have tried many sample codes that work fine Thanks

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