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  • how to store a 2D game world in mysql

    - by monthon1
    I am making a 2D game in javascript/ajax, that will be using data stored in mysql database. Every user have got his own "area" made of small squares that can have some values. But I have no idea, how to store values of each square in mysql, when each user can have area with different width or height. Do you have some idea?

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  • Simple wave generator with SDL in c++

    - by Vlad Popescu
    i am having problems understanding how the audio part of the sdl library works now, i know that when you initialize it, you have to specify the frequency and a callback<< function, which i think is then called automatically at the given frequency. can anyone who worked with the sdl library write a simple example that would use sdl_audio to generate a 440 hz square wave (since it is the simplest waveform) at a sampling frequency of 44000 hz? thanks in advance

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  • printing using one '\n'

    - by Alex
    I am pretty sure all of you are familiar with the concept of the Big4, and I have several stuffs to do print in each of the constructor, assignment, destructor, and copy constructor. The restriction is this: I CAN'T use more than one newline (e.g., ƒn or std::endl) in any method I can have a method called print, so I am guessing print is where I will put that precious one and only '\n', my problem is that how can the method print which prints different things on each of the element I want to print in each of the Big4? Any idea? Maybe overloading the Big4?

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  • SQL Server many-to-many design recommendation

    - by Jean-Philippe Brabant
    I have a SQL Server database with two table : Users and Achievements. My users can have multiple achievements so it a many-to-many relation. At school we learned to create an associative table for that sort of relation. That mean creating a table with a UserID and an AchivementID. But if I have 500 users and 50 achievements that could lead to 25 000 row. As an alternative, I could add a binary field to my Users table. For example, if that field contained 10010 that would mean that this user unlocked the first and the fourth achievements. Is their other way ? And which one should I use.

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  • I'm confused with block in ruby, compared to smalltalk.

    - by weakish
    What does block in ruby mean? It looks similar with smalltalk, but you can't send messages to it. For example, in smalltalk: [:x | x + 3] value: 3 returns 6. But in ruby: {|x| x + 3}.call 3 will cause SyntaxError. Well, you can pass messages to lambda in ruby, though: irb(main):025:0> ->(x){x+3}.call 3 => 6 So in ruby, block is not a block, but lambda is a block? Is this true? I mean, are there any differences between ruby lambda and smalltalk block? If this is true, then what is ruby block?

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  • my .jar file won't do anything.

    - by David
    I created a program that more or less holds an array of strings as an object and randomly prints one. so basicaly class Happy { string[] namestrings = new string[#] constructor() { fill with some strings} public static void main (String[]arg) { create instance of class do some junk with it method that prints it } method that prints it {} another method } when i compile and run it on the command line it works fine but when on the comand line i type in jar -cf Happy.jar Fun.class i get a .jar file called Happy and when i click on it i get an error message that reads "the java Jar file happy could not be launched read the consol for possible error messages" I have a mac i'm running lepord if that makes a diference. Whats going on?

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  • How to avoid automatic renaming of sub signature parameters in visual basic 6.

    - by systempuntoout
    In Visual basic 6, i declare a sub like this: Private Sub test1(ByRef XmlFooOutput As String) ... End Sub after that, i declare another sub like the following one: Private Sub test2(ByRef xmlFooOutput As String) ... End Sub automagically, the first method is transformed in: Private Sub test1(ByVal xmlFooOutput As String) ... End Sub so the XmlFooOutput parameter is transformed in xmlFooOutput. This is a pretty dangerous feature because, method like those could be mapped to different XSL presentation files that read XML values through Xpath. So when test1 parameter is renamed, XSL bound to test1 method goes broken because Xpath point to XmlFooOuput but the correct value is now in xmlFooOutput. Is it possible to remove this weird feature? I'm using microsoft visual basic 6.0 (SP6). This question has some duplicate: http://stackoverflow.com/questions/1064858/stop-visual-basic-6-from-changing-my-casing http://stackoverflow.com/questions/248760/vb6-editor-changing-case-of-variable-names from what i see, there's no practical solution to disable this Intellisense evil feature.

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  • Determining filetype of file in assets folder

    - by ChaimKut
    Question: How do you programmatically distinguish between directories and regular files in the assets folder? When using AssetManager to access files in the assets folder, it seems impossible to determine if a file is in fact a file or a directory. You get the list of files from the list method and then open the file using the open method. I thought perhaps using the openFd method to get the asset file descriptor (and then subsequently requesting the normal file descriptor) would provide me some information. But requesting the file descriptor for a directory results in an IOException (which makes sense since what would it mean for a directory to have a file descriptor...?). Currently I'm relying on that IOException (resulting from attemptng to open a directory in the assets folder) in order to determine if a file is in fact a directory. (Opening a regular file works just fine). This seems like a bad idea. Any other suggestions to distinguish between a file and a directory?

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  • drawing circle without floating point calculation

    - by zaharpopov
    This is common interview question (according to some interview sites) but I can find no normal answers in Internet - some are wrong and some point to complex theory I expect not looked for in interview (like Bressenham algorithm). The question is simple: The circle equation is: x^2 + y^2 = R^2. Given R, draw 0,0-centered circle as best as possible without using any floating point (no trigo, square roots, and so on, only integers)

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  • view is not rendered when returning ModelAndView

    - by adancu
    Hi, I have the following problem. I need to export a PDF in a controller The code below, where I return a View, works as expected. @RequestMapping(method = RequestMethod.GET) public View exportReport( @RequestParam(value = "userName", required = true) String userName, @RequestParam(value = "startDate", required = true) Date startDate, @RequestParam(value = "endDate", required = true) Date endDate) { /////////////////////////////////////////// return new TimeSheetReportPdfView(); } The problem occurs if I change the method to return a ModelAndView: @RequestMapping(method = RequestMethod.GET) public ModelAndView exportReport( @RequestParam(value = "userName", required = true) String userName, @RequestParam(value = "startDate", required = true) Date startDate, @RequestParam(value = "endDate", required = true) Date endDate) { /////////////////////////////////////////// return new ModelAndView(new TimeSheetReportPdfView(), model); } Now, the PDF is not exported, all I get is a blank page and nothing in the logs. Any help appreciated. Thanks.

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  • Multiple Asserts in a Unit Test

    - by whatispunk
    I've just finished reading Roy Osherove's "The Art of Unit Testing" and I am trying to adhere to the best practices he lays out in the book. One of those best practices is to not use multiple asserts in a test method. The reason for this rule is fairly clear to me, but it makes me wonder... If I have a method like: public Foo MakeFoo(int x, int y, int z) { Foo f = new Foo(); f.X = x; f.Y = y; f.Z = z; return f; } Must I really write individual unit tests to assert each separate property of Foo is initialized with the supplied value? Is it really all that uncommon to use multiple asserts in a test method? FYI: I am using MSTest.

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  • Public static variables and Android activity life cycle management

    - by jsstp24n5
    According to the documentation the Android OS can kill the activity at the rear of the backstack. So, say for example I have an app and open the Main Activity (let's call it Activity A). In this public activity class I declare and initialize a public static variable (let's call it "foo"). In Activity A's onCreate() method I then change the value of "foo." From Activity A the user starts another activity within my app called Activity B. Variable "foo" is used in Activity B. Activity B is then paused after the user navigates to some other activities in other apps. Eventually, after a memory shortage occurs, Activity A then Activity B can be killed. After the user navigates back to my app it restarts (actually "recreates") activity B. What happens: 1) Will variable "foo" at this point have the value that was set to it when Activity A's onCreate() method ran? 2) Variable "foo" does not exist? 3) Variable "foo" exists and but is now the initialized value and not the value set in Activity A's onCreate() method?

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  • Have threads run indefinitely in a java application

    - by TP
    I am trying to program a game in which I have a Table class and each person sitting at the table is a separate thread. The game involves the people passing tokens around and then stopping when the party chime sounds. how do i program the run() method so that once I start the person threads, they do not die and are alive until the end of the game One solution that I tried was having a while (true) {} loop in the run() method but that increases my CPU utilization to around 60-70 percent. Is there a better method?

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  • Questions regarding PHPUnit mock feature

    - by Andree
    Can someone provide me a reference to a good PHPUnit mock guide? The one in the official documentation doesn't seem to be detailed enough. I need to know about the following: 1) How to expect multiple calls to a mock object's method, but each return a different sets of value? $tableMock->expects($this->exactly(2)) ->method('find') ->will($this->returnValue(2)); // I need the second call to return different value 2) How to expect a call to a mock object's method with multiple parameters?

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  • help with reflections and annotations in java

    - by Yonatan
    Hello Internet ! I'm having trouble with doubling up on my code for no reason other than my own lack of ability to do it more efficiently... `for (Method curr: all){ if (curr.isAnnotationPresent(anno)){ if (anno == Pre.class){ for (String str : curr.getAnnotation(Pre.class).value()){ if (str.equals(method.getName()) && curr.getReturnType() == boolean.class && curr.getParameterTypes().length == 0){ toRun.add(curr); } } } if (anno == Post.class) { for (String str : curr.getAnnotation(Post.class).value()){ if (str.equals(method.getName()) && curr.getReturnType() == boolean.class && curr.getParameterTypes().length == 0){ toRun.add(curr); } } } } }` anno is a parameter - Class, and Pre and Post are my annotations, both have a value() which is an array of strings. Of course, this is all due to the fact that i let Eclipse auto fill code that i don't understand yet.

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  • R: Plotting a graph with different colors of points based on advanced criteria

    - by balconydoor
    What I would like to do is a plot (using ggplot), where the x axis represent years which have a different colour for the last three years in the plot than the rest. The last three years should also meet a certain criteria and based on this the last three years can either be red or green. The criteria is that the mean of the last three years should be less (making it green) or more (making it red) than the 66%-percentile of the remaining years. So far I have made two different functions calculating the last three year mean: LYM3 <- function (x) { LYM3 <- tail(x,3) mean(LYM3$Data,na.rm=T) } And the 66%-percentile for the remaining: perc66 <- function(x) { percentile <- head(x,-3) quantile(percentile$Data, .66, names=F,na.rm=T) } Here are two sets of data that can be used in the calculations (plots), the first which is an example from my real data where LYM3(df1) < perc66(df1) and the second is just made up data where LYM3 perc66. df1<- data.frame(Year=c(1979:2010), Data=c(347261.87, 145071.29, 110181.93, 183016.71, 210995.67, 205207.33, 103291.78, 247182.10, 152894.45, 170771.50, 206534.55, 287770.86, 223832.43, 297542.86, 267343.54, 475485.47, 224575.08, 147607.81, 171732.38, 126818.10, 165801.08, 136921.58, 136947.63, 83428.05, 144295.87, 68566.23, 59943.05, 49909.08, 52149.11, 117627.75, 132127.79, 130463.80)) df2 <- data.frame(Year=c(1979:2010), Data=c(sample(50,29,replace=T),75,75,75)) Here’s my code for my plot so far: plot <- ggplot(df1, aes(x=Year, y=Data)) + theme_bw() + geom_point(size=3, aes(colour=ifelse(df1$Year<2008, "black",ifelse(LYM3(df1) < perc66(df1),"green","red")))) + geom_line() + scale_x_continuous(breaks=c(1980,1985,1990,1995,2000,2005,2010), limits=c(1978,2011)) plot As you notice it doesn’t really do what I want it to do. The only thing it does seem to do is that it turns the years before 2008 into one level and those after into another one and base the point colour off these two levels. Since I don’t want this year to be stationary either, I made another tiny function: fun3 <- function(x) { df <- subset(x, Year==(max(Year)-2)) df$Year } So the previous code would have the same effect as: geom_point(size=3, aes(colour=ifelse(df1$Year<fun3(df1), "black","red"))) But it still does not care about my colours. Why does it make the years into levels? And how come an ifelse function doesn’t work within another one in this case? How would it be possible to the arguments to do what I like? I realise this might be a bit messy, asking for a lot at the same time, but I hope my description is pretty clear. It would be helpful if someone could at least point me in the right direction. I tried to put the code for the plot into a function as well so I wouldn’t have to change the data frame at all functions within the plot, but I can’t get it to work. Thank you!

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  • Dynamically adding @property in python

    - by rz
    I know that I can dynamically add an instance method to an object by doing something like: import types def my_method(self): # logic of method # ... # instance is some instance of some class instance.my_method = types.MethodType(my_method, instance) Later on I can call instance.my_method() and self will be bound correctly and everything works. Now, my question: how to do the exact same thing to obtain the behavior that decorating the new method with @property would give? I would guess something like: instance.my_method = types.MethodType(my_method, instance) instance.my_method = property(instance.my_method) But, doing that instance.my_method returns a property object.

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  • Is it bad to have the <link> tag for hCard when there is no hCard on that page?

    - by Evan Carroll
    I'm just wondering if it is bad practice to put the <link> tag for hCard profile on every page, if you don't know that the page being rendered has an hCard. My site has hCards - is it worth trimming the link tag out of the pages that don't have them? <link rel="profile" href="http://microformats.org/profile/hcard"> Does this mean this page has an hCard or look for an hCard on this page? Does it mean interpret an hCard as specified, if found? Obviously, you can pull in stylesheets using <link> but they apply to the page. I don't even see anything at that destination other than some sub-par hCard documentation.

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  • Reflection: take values from an unknown running alpplication

    - by Dr.Lesh
    I'm writing an application that searchs for Semaphore types in the fields of unknown classes in unknown application (passed by user). I made it using Reflection and it worked. Now I want to fill up these semaphores with values, taking them from a running instance of this unknown application. So i took the class with "main" method of this unknown application, made a newInstance, and passed it when invoking the main method to start the application: Class mainClass = getItSomeWhere(); Object instance = mainClass.newInstance(); Method mainMethod = mainClass.getDeclaredMethod("main", new Class[]{String[].class}); mainMethod.invoke(instance, new Object[]{args}); and it worked fine. Now, how can I get the semaphore values, taking them from the classes of this running application, when I only have an instance of the main class? Many thanks for the answers.

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  • Get annotations of return type in Java

    - by Apropos
    I'm using Spring MVC and am using aspects to advise my controllers. I'm running into one issue: controllers that return a value annotated with the @ResponseBody type. How are you able to find the annotations applied to the return type? @Around("myPointcut()") private Object checkAnnotations(ProceedingJoinPoint pjp) throws Throwable { Object result = pjp.proceed(); Method method = ((MethodSignature)pjp.getSignature()).getMethod(); System.out.println("Checking return type annotations."); for(Annotation annotation : method.getReturnType().getAnnotations()){ System.out.println(annotation.toString()); } System.out.println("Checking annotations on returned object."); for(Annotation annotation : result.getClass().getAnnotations()){ System.out.println(annotation.toString()); } return result; } Unfortunately, neither of these methods seem to have the desired effect. I can retrieve annotations on the type of object being returned, but not the ones being added at return time.

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  • Is the a pattern for iterating over lists held by a class (dynamicly typed OO languages)

    - by Roman A. Taycher
    If I have a class that holds one or several lists is it better to allow other classes to fetch those lists(with a getter) or to implement a doXList/eachXList type method for that list that take a function and call that function on each element of the list contained by that object. I wrote a program that did a ton of this and I hated passing around all these lists sometimes with method in class a calling method in class B to return lists contained in class C, B contains a C or multiple C's (note question is about dynamically typed OO languages languages like ruby or smalltalk) ex. (that came up in my program) on a Person class containing scheduling preferences and a scheduler class needing to access them.

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  • Recommended ASP.NET Shared Hosting

    - by coffeeaddict
    Ok, I have to admit I'm getting fed up with www.discountasp.net's pricing model and this annoyance has built up over the past 8 years or so. I've been with them for years and absolutely love them on the technical side, however it's getting ridiculously expensive for so little that you get. I mean here's my scenario: 1) I am running 2 SQL Server databases which costs me $10/ea per month so that's $20/month for 2 and I only get 500 mb disk space which is horrible 2) I am paying $10/mo just for the hosting itself which I only get 1 gig of disk space! I mean common! 3) I am simply running 2 small apps (Screwturn Wiki & Subtext Blog)...so I don't really care if it's up 99% or not, it's not worth paying a total of $300 just to keep these 2 apps running over discountasp.net Anyone else feel the same? Yes, I know they have great support, probably have great servers running behind this but in the end I really don't care as long as my site is up 95% or better. Yes, the hosting toolset rocks. But you know I bet you I can find a similar set somewhere else. I like how I can totally control IIS 7 at discountasp and I can control my own app pool etc. That's very powerful and essential. But anyone have any good alternatives to discountasp that gives me close to the same at a much more reasonable cost point? I mean http://www.m6.net/prices.aspx gives you 10 SQL Databases for $7 and 200 gigs disk space! I don't know about their tools or support but just looking at those numbers and some other hosts I've seen, I feel that discountasp.net is way out of line. They don't even offer any purchasing discounts such as it would be nice if my 2nd SQL Server is only $5/month not $10...stuff like this, to make it much more realistic and fair. Opinions (people who do have discountasp.net, people who have left them, or people who have another host they like)??? But geez $300 just to host a couple DBs and lightweight open source apps? Not worth the price they are charging. I'm almost at a price point that enables me to get a decent dedicated server! I really don't care about beta support. Not a big deal to me.

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