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  • Setup for games animation: How do I know JFrame is finished setting itself up?

    - by Jokkel
    I'm using javax.swing.JFrame to draw game animations using double buffer strategy. First, I set up the frame. JFrame frame = new JFrame(); frame.setVisible(true); Now, I draw an object (let it be a circle, doesn't matter) like this. frame.createBufferStrategy(2); bufferStrategy = frame.getBufferStrategy(); Graphics g = bufferStrategy.getDrawGraphics(); circle.draw(g); bufferStrategy.show(); The problem is that the frame is not always fully set-up when the drawing takes place. Seems like JFrame needs up to three steps in resizing itself, until it reaches it's final size. That makes the drawing slide out of frame or hinders it to appear completely from time to time. I already managed to delay things using SwingUtilities.invokeLater(). While this improved the result, there are still times when the drawing slides away / looks prematurely draw. Any idea / strategy? Thanks in advance. EDIT: Ok thanks so far. I didn't mention that I write a little Pong game in the first place. Sorry for the confusion What I actually looked for was the right setup for accelerated game animations done in Java. While reading through the suggestions I found my question answered (though indirectly) here and this example made things clear for me. A resume for this might be that for animating game graphics in Java, the first step is to get rid of the GUI logic overhead.

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  • How to access remote mysql host on Ubuntu inside VMware?

    - by Nick Grossman
    Hi, I'm running Ubuntu 10.10 inside VMware fusion on Mac OSX Snow Leopard. Inside ubuntu, I'm attempting to use command-line mysql to connect to a database hosted on a separate web server. For some reason, mysql misinterprets the remote hostname as a local address, and is not able to connect to the database. Steps: (from ubuntu inside VMware) mysql -u <my-username> -h mysql-2.sandbox.wrkng.net -p Enter Password: <my password> expected: to log into mysql got: ERROR 1045 (28000): Access denied for user '<my-username>'@'c-71-233-98-90.hds1.ma.comcast.net' (using password: YES) Note that the hostname referenced in the error message is different than the one I inputted to the mysql command. Also, performing the same command from the Mac (host of the VM) terminal successfully connects to the database. I am not seasoned with VMware or linux, so I may be missing something obvious here -- it seems like somewhere along the way either ubuntu or the VM has a networking issue. Note also that accessing the internet via ubuntu inside the VM works fine. Any help is greatly appreciated. Thanks!

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  • regular expression repeating subexpression

    - by Michael Z
    I have the following text <pattern name="pattern1"/> <success>success case 1</success> <failed> failure 1</failed> <failed> failure 2</failed> <unknown> unknown </unknown> <pattern name="pattern2"/> <success>success case 2</success> <otherTag>There are many other tags.</otherTag> <failed> failure 3</failed> And the regular expression <failed>[\w|\W]*?</failed> matches all the lines contains failed tag. What do I need to to if I want to include the lines contains pattern tag as well? Basically, I want the following output: <pattern name="pattern1"/> <failed> failure 1</failed> <failed> failure 2</failed> <pattern name="pattern2"/> <failed> failure 3</failed> I am doing this in javascript, I do not mind of doing some intermediate steps.

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  • Can't Add XSD to Class Project

    - by Jeff
    Background: I started with a large solution with many applications in it in VS 2008 and I'm trying to split it up. Steps to repeat: I create a new VS 2010 C# class project I right click and choose add existing item I choose the XSD file from my old project and import it. The original file is 67KB the imported file is 18KB Line 134,135 of the original file <Mapping SourceColumn="ConfigType" DataSetColumn="ConfigType" /> <Mapping SourceColumn="ConfigValue" DataSetColumn="ConfigValue" /> Line 135,136 of the resulting file <Mapping SourceColumn="ConfigType" DataSetColumn="ConfigType" /> <Mappi Part way through it's life my old project was upgrade from 2.0 to 3.5 so some of the code is. Manually copy and paste of the xsd source into the new file and updating the 2.0.0.0 to 4.0.0.0 allowed me to open it it in The GUI for editing XSD files. After fixing all the connection strings and right clicking on every query and clicking configure then finish I was able to gain access to one of the tableadapters out of 6. I'm stumped as to hoe to get this to compile. Once it compiles I'm open sourcing it so ask if you want to see the code.

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  • How to drop/restart a client connection to a flaky socket server

    - by Steve Prior
    I've got Java code which makes requests via sockets from a server written in C++. The communication is simply that the java code writes a line for a request and the server then writes a line in response, but sometimes it seems that the server doesn't respond, so I've implemented an ExecutorService based timeout which tries to drop and restart the connection. To work with the connection I keep: Socket server; PrintWriter out; BufferedReader in; so setting up the connection is a matter of: server = new Socket(hostname, port); out = new PrintWriter(new OutputStreamWriter(server.getOutputStream())); in = new BufferedReader(new InputStreamReader(socket.getInputStream())); If it weren't for the timeout code the request/receive steps are simply: String request="some request"; out.println(request); out.flush(); String response = in.readLine(); When I received a timeout I was trying to close the connection with: in.close(); out.close(); socket.close(); but one of these closes seems to block and never return. Can anyone give me a clue why one of these would block and what would be the proper way to abandon the connection and not end up with resource leak issues?

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  • .NET MVC What is the best way to disable browser caching?

    - by Chameera Dedduwage
    As far as my research goes, there are several steps in order to make sure that browser caching is disabled. These HTTP headers must be set: Cache-Control: no-cache, no-store, must-revalidate, proxy-revalidate Pragma: no-cache, no-store Expires: -1 Last-Modified: -1 I have found out that this can be done in two ways: Way One: use the web.config file <add name="Cache-Control" value="no-store, no-cache, must-revalidate, proxy-revalidate"/> <add name="Pragma" value="no-cache, no-store" /> <add name="Expires" value="-1" /> <add name="Last-Modified" value="-1" /> Way Two: use the meta tags in _Layout.cshtml <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate, proxy-revalidate" /> <meta http-equiv="Pragma" content="no-cache, no-store" /> <meta http-equiv="Expires" content="-1" /> <meta http-equiv="Expires" content="-1" /> My Question: which is the better approach? Or, alternatively, are they equally acceptable? How do these all relate to different platforms? Which browsers would honor what headers? In addition, please feel free to add anything I've missed, if any.

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  • Word frequency tally script is too slow

    - by Dave Jarvis
    Background Created a script to count the frequency of words in a plain text file. The script performs the following steps: Count the frequency of words from a corpus. Retain each word in the corpus found in a dictionary. Create a comma-separated file of the frequencies. The script is at: http://pastebin.com/VAZdeKXs Problem The following lines continually cycle through the dictionary to match words: for i in $(awk '{if( $2 ) print $2}' frequency.txt); do grep -m 1 ^$i\$ dictionary.txt >> corpus-lexicon.txt; done It works, but it is slow because it is scanning the words it found to remove any that are not in the dictionary. The code performs this task by scanning the dictionary for every single word. (The -m 1 parameter stops the scan when the match is found.) Question How would you optimize the script so that the dictionary is not scanned from start to finish for every single word? The majority of the words will not be in the dictionary. Thank you!

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  • App Crashing Inspite of Being ARC Enabled

    - by proctr
    I have been working on an iOS App for sometime now and its almost ready to submit. However, when I gave it to few people for testing purposes (running iOS 5)..they reported cases where the app crashes and the home screen is displayed on the phone OR a frozen app screen appears with no response whatsoever The app is ARC enabled and Xcode shows no warnings. So, I'm relli tensed about what's going wrong. I have declared properties in the following fashion: @property (nonatomic) IBOutlet UILabel *devCountLabel; @property (nonatomic) IBOutlet UIView *splashView; Likewise other properties are declared. Could anyone provide a solution ASAP. It is mainly a network based app and thus, CoreData usage is minimum.. Anyway, I'm running out of time..So Please provide a fix asap..oh and thanks a ton for it. PS: The App doesn't crash in the simulator, so I'm guessing it has something related to memory. And the crashes are random. So, repeating a set of steps to reproduce the crash doesn't help either. For Eg. When I click a button, modalViewControllerAnimation results in normal case. Now this occurs as expected most of the time and freezes the app other times.

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  • please suggest mysql query for this

    - by I Like PHP
    I HAVE TWO TABLES shown below table_joining id join_id(PK) transfer_id(FK) unit_id transfer_date joining_date 1 j_1 t_1 u_1 2010-06-05 2010-03-05 2 j_2 t_2 u_3 2010-05-10 2010-03-10 3 j_3 t_3 u_6 2010-04-10 2010-01-01 4 j_5 NULL u_3 NULL 2010-06-05 5 j_6 NULL u_4 NULL 2010-05-05 table_transfer id transfer_id(PK) pastUnitId futureUnitId effective_transfer_date 1 t_1 u_3 u_1 2010-06-05 2 t_2 u_6 u_1 2010-05-10 3 t_3 u_5 u_3 2010-04-10 now i want to know total employee detalis( using join_id) which are currently working on unit u_3 . means i want only join_id j_1 (has transfered but effective_transfer_date is future date, right now in u_3) j_2 ( tansfered and right now in `u_3` bcoz effective_transfer_date has been passed) j_6 ( right now in `u_3` and never transfered) what i need to take care of below steps( as far as i know ) <1> first need to check from table_joining whether transfer_id is NULL or not <2> if transfer_id= is NULL then see unit_id=u_3 where joining_date <=CURDATE() ( means that person already joined u_3) <3> if transfer_id is NOT NULL then go to table_transfer using transfer_id (foreign key reference) <4> now see the effective_transfer_date regrading that transfer_id whether effective_transfer_date<=CURDATE() <5> if transfer date has been passed(means transfer has been done) then return futureUnitID otherwise return pastUnitID i used two separate query but don't know how to join those query?? for step <1 ans <2 SELECT unit_id FROM table_joining WHERE joining_date<=CURDATE() AND transfer_id IS NULL AND unit_id='u_3' for step<5 SELECT IF(effective_transfer_date <= CURDATE(),futureUnitId,pastUnitId) AS currentUnitID FROM table_transfer // here how do we select only those rows which have currentUnitID='u_3' ?? please guide me the process?? i m just confused with JOINS. i think using LEFT JOIN can return the data i need, or if we use subquery value to main query? but i m not getting how to implement ...please help me. Thanks for helping me alwayz

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  • In C/C++,how to link dynamic link lib which compiled in GCC/G++ in MS VStudio?

    - by coanor
    These days, I use Flex & Bison generated some codes to develop a SQL-parser alike tools, these code can't compiled silently(may be this another topic) in VS2005,but GCC/G++ works well, then I compiled these code with mingw in dll(in windows xp), and then linked these function facades in VS2005, but it seems can't link the dll during linking. Does MS VS2005 recognize the dll which compiled using mingw on windows? Is there anything I need to do additional? For example, adding something in the include-file that declare the exported APIs? Does any one can give some advices? The condition is, as in VS2005, if you want to export some APIs, you may show a *.def file to tell nmake which API you want to export, and then you may create a(or some) *.h file to declare somthing about these APIs(adding some stdcall alike prefix as a call protocal) and some data-type definition. But with GCC/G++, you do not need to do such boring things, just use [ar], you can get these APIs, so my *.h file do not add call protocol and no *.def, just like common function declaration. After *.dll generated, add the *.h file and [mv] generated *.dll in VS2005 project directory, then set the linking *.dll in project setting. Does these steps generated my Question? BTW, I found and tested VC6-compiled dll can be linked with mingw in Windows XP, but the reverse can't work. Anyway, forgive my poor English, and thanks for your concern.

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  • Replacing XML in File from "Document" in Java

    - by poeschlorn
    Hi, after processing my first steps in working with XML in java I am now at the point where I want to update some data in my XML/GPX file... Reaplacing it in my "Document" data type works great :) How here comes the question: how can I store the changed "document"-model back to my file? Do I have to do this by using the standart file-functions (via steams and so on) oder is the a more elegant way to do this? ;-) Here's the code I already worked out, maybe that could help. (the method getParsedXML is just puting the conversion from the file into an extra method) Document tmpDoc = getParsedXML(currentGPX); //XML Parsind tests: // Access to tag attribute <tag attribut="bla"> System.out.println(tmpDoc.getElementsByTagName("wpt").item(0).getAttributes().getNamedItem("lat").getTextContent()); // Access to the value of an child element <a><CHILD>ValueOfChild</CHILD></a> System.out.println(tmpDoc.getElementsByTagName("wpt").item(0).getChildNodes().item(5).getTextContent()); // Replacing access to tag attribute tmpDoc.getElementsByTagName("wpt").item(0).getAttributes().getNamedItem("lat").setTextContent("139.921055008"); System.out.println(tmpDoc.getElementsByTagName("wpt").item(0).getAttributes().getNamedItem("lat").getTextContent()); // Replacing access to child element value tmpDoc.getElementsByTagName("wpt").item(0).getChildNodes().item(5).setTextContent("Cala Sant Vicenç - Mallorca 2"); System.out.println(tmpDoc.getElementsByTagName("wpt").item(0).getChildNodes().item(5).getTextContent());

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  • BitmapFactory.decodeFile out of memory with images 2400x2400

    - by alasarr
    I need to send an image from a file to a server. The server request the image in a resolution of 2400x2400. What I'm trying to do is: 1) Get a Bitmap using BitmapFactory.decodeFile using the correct inSampleSize. 2) Compress the image in JPEG with a quality of 40% 3) Encode the image in base64 4) Sent to the server I cannot achieve the first step, it throws an out of memory exception. I'm sure the inSampleSize is correct but I suppose even with inSampleSize the Bitmap is huge (around 30 MB in DDMS). Any ideas how can do it? Can I do these steps without created a bitmap object? I mean doing it on filesystem instead of RAM memory. This is the current code: // The following function calculate the correct inSampleSize Bitmap image = Util.decodeSampledBitmapFromFile(imagePath, width,height); // compressing the image ByteArrayOutputStream baos = new ByteArrayOutputStream(); image.compress(Bitmap.CompressFormat.JPEG, 40, baos); // encode image String encodedImage = Base64.encodeToString(baos.toByteArray(),Base64.DEFAULT));

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  • Cannot connect to mysql via servlet

    - by JBoy
    Hi all I have been since 2 days trying to figure out why my servlet does not connect to the database MySql. I have mysql installed and working properly and eclipse. Whenever i try to etabilish a connection i get the ClassNotFoundException for the com.mysql.jdbc.Driver, which is actually properly imported, the connector i'm using is the mysql-connector-java5.1.14 added properly as external jar so everything seems fine. here's my code protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String dbUrl="jdbc:mysql://localhost:3306/test"; String username="root"; String password=""; try { Class.forName("com.mysql.jdbc.Driver").newInstance(); conn=DriverManager.getConnection(dbUrl); System.out.println("Connected!"); } catch (SQLException e) { e.printStackTrace(); System.out.println("not connected"); } catch(ClassNotFoundException x){ x.printStackTrace(); } catch(Exception e){ e.printStackTrace(); } } The stacktrace(part of): java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1645) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1491) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:375) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:164) i'm following the connection steps from a published java book and also in forums and tutorials i just see the same code, cannot figure out why that Exception comes. On a normal application which does not run on the server the Exception isn't thrown and the connection (in the exact same way) its successfull. Do you have any advice?

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  • Specifying a DLL reference

    - by Jesse
    I'm having trouble setting the path to a DLL that is not in the same directory as the executable. I have a reference to dllA.dll. At present, everything is just copied into the same directory and all is well; however, I need to move the executable to another directory while still referencing the DLL in the original directory. So, it's setup like: C:\Original\Dir program.exe dllA.dll dllB.dll dllC.dll But I need to have it setup like: C:\New\Dir program.exe dllB.dll dllC.dl Such that it is still able to reference dllA.dll in C:\Original\dir I tried the following, but to no avail: Set the "Copy Local" value to false for dllA.dll because I want it to be referenced in its original location. Under "Tools Options Projects and Solutions VC++ Directories" I have added the path to "C:\Original\Dir" Added "C:\Original\Dir" to both the PATH and LIB environment variables At runtime, it informs me that it cannot locate dllA.dll Maybe the above steps I took only matter at compile time? I was able to find this http://stackoverflow.com/questions/1382704/c-specifying-a-location-for-dll-reference But I was thinking that my above method should've worked. Any ideas?

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  • populating an nsarray

    - by MoKaM
    I intend to make a program that does the following: Create an NSArray populated with numbers from 1 to 100,000. Loop over some code that deletes certain elements of the NSArray when certain conditions are met. Store the resultant NSArray. However the above steps will also be looped over many times and so I need a fast way of making this NSArray that has 100,000 number elements. So what is the fastest way of doing it? Is there an alternative to iteratively populating an Array using a for loop? Such as an NSArray method that could do this quickly for me? Or perhaps I could make the NSArray with the 100,000 numbers by any means the first time. And then create every new NSArray (for step 1) by using method arraywithArray? (is it quicker way of doing it?) Or perhaps you have something completely different in mind that will achieve what I want. edit: Replace NSArray with NSMutableArray in this post.

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  • Update table instantly or “Bulk” Update in database later? And is it advisable?

    - by Mestika
    Hi, I have a question regarding a semi-constant update in a database. In short it is regarding a checkout function on a web page, which each time the checkout function is evoked it do five steps. I want to try to optimize this function and have my eye on a step where I update a table each time the checkout is performed. I take the information retrieved from the shopping cart and then update the table in question. I do have some indexes on the table, the gain from those are greater than leaving them so this is a cost I’m willing to take. Now, my question is. Could it in some way regarding to performance be better to not update the table instantly but collect every checkout items and save them in some way (maybe in a file) and then at a specific time (or several times) at day take this file and then update the table with the new information. Then I started thinking about if there was a possibility to use some sort of Bulk Update to take a file, hashmap, array (or?) and then update it. And I’m using IBM DB2 version 9.7 Mestika

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  • Windows service (hosting WCF service) stops immediately on start up

    - by Thr33Dii
    My Question: I cannot navigate to the base address once the service is installed because the service won't remain running (stops immediately). Is there anything I need to do on the server or my machine to make the baseAddress valid? Background: I'm trying to learn how to use WCF services hosted in Windows Services. I have read several tutorials on how to accomplish this and it seems very straight forward. I've looked at this MSDN article and built it step-by-step. I can install the service on my machine and on a server, but when I start the service, it stops immediately. I then found this tutorial, which is essentially the same thing, but it contains some clients that consume the WCF service. I downloaded the source code, compiled, installed, but when I started the service, it stopped immediately. Searching SO, I found a possible solution that said to define the baseAddress when instantiating the ServiceHost, but that didnt help either. My serviceHost is defined as: serviceHost = new ServiceHost( typeof( CalculatorService ), new Uri( "http://localhost:8000/ServiceModelSamples/service" ) ); My service name, base address, and endpoint: <service name="Microsoft.ServiceModel.Samples.CalculatorService" behaviorConfiguration="CalculatorServiceBehavior"> <host> <baseAddresses> <add baseAddress="http://localhost:8000/ServiceModelSamples/service"/> </baseAddresses> </host> <endpoint address="" binding="wsHttpBinding" contract="Microsoft.ServiceModel.Samples.ICalculator"/> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/> </service> I've verified the namespaces are identical. It's just getting frustrating that the tutorials seem to assume that the Windows service will start as long as all the stated steps are followed. I'm missing something and it's probably right in front of me. Please help!

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  • Why does false invalidate validates_presence_of?

    - by DJTripleThreat
    Ok steps to reproduce this: prompt> rails test_app prompt> cd test_app prompt> script/generate model event_service published:boolean then go into the migration and add not null and default published to false: class CreateEventServices < ActiveRecord::Migration def self.up create_table :event_services do |t| t.boolean :published, :null => false, :default => false t.timestamps end end def self.down drop_table :event_services end end now migrate your changes and run your tests: prompt>rake db:migrate prompt>rake You should get no errors at this time. Now edit the model so that you validate_presence_of published: class EventService < ActiveRecord::Base validates_presence_of :published end Now edit the unit test event_service_test.rb: require 'test_helper' class EventServiceTest < ActiveSupport::TestCase test "the truth" do e = EventServer.new e.published = false assert e.valid? end end and run rake: prompt>rake You will get an error in the test. Now set e.published to true and rerun the test. IT WORKS! I think this probably has something to do with the field being boolean but I can't figure it out. Is this a bug in rails? or am I doing something wrong?

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  • Windows Phone 7.1.1 Ping

    - by Matt
    I am writing an app to connect to a third party application using REST web services. I have a configuration page that asks for an IP, Port, User Name & Password, currently it just blindly assumes you enter the correct details and attempts a connection. I want to create a test routine that goes through and checks off the following steps when setting up the config information Is the IP/Hostname correct (using ping or something) Is the Port correct Is the Username & Password correct then displays the results on screen as it's going so that if it can't connect to the service it's easier to identify where the issue is. To achieve step 1 I would like to use Ping or some equivalent that does not rely on a particular port being open. So I can eliminate dodgy DNS or a typo in the IP/Hostname. I understand from previous questions asked that ping wasn't possible in 7.0 but with Mango the sockets classes have been added in, is it possible now, if so how? If it still isn't possible is there a different way I can achieve step 1?

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  • generate k distinct number less then n

    - by davit-datuashvili
    hi i have following question task is this generate k distinct positive numbers less then n without duplication my method is following first create array size of k where we should write these numbers int a[]=new int[k]; //now i am going to cretae another array where i check if (at given number position is 1 then generate number again else put this number in a array and continue cycle i put here a piece of code and explanations int a[]=new int[k]; int t[]=new int[n+1]; Random r=new Random(); for (int i==0;i<t.length;i++){ t[i]=0;//initialize it to zero } int m=0;//initialize it also for (int i=0;i<a.length;i++){ m=r.nextInt(n);//random element between 0 and n if (t[m]==1){ //i have problem with this i want in case of duplication element occurs repeats this steps afain until there will be different number else{ t[m]=1; x[i]=m; } } so i fill concret my problem if t[m]==1 it means that this element occurs already so i want to generate new number but problem is that number of generated numbers will not be k beacuse if i==0 and occurs duplicate element and we write continue then it will switch at i==1 i need like goto for repeat step or for (int i=0;i<x.length;i++){ loop: m=r.nextInt(n); if ( x[m]==1){ continue loop; } else{ x[m]=1; a[i]=m; continue;//continue next step at i=1 and so on } } i need this code in java please help

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  • How can I have a single helper work on different models passed to it?

    - by Angela
    I am probably going to need to refactor in two steps since I'm still developing the project and learning the use-cases as I go along since it is to scratch my own itch. I have three models: Letters, Calls, Emails. They have some similarilty, but I anticipate they also will have some different attributes as you can tell from their description. Ideally I could refactor them as Events, with a type as Letters, Calls, Emails, but didn't know how to extend subclasses. My immediate need is this: I have a helper which checks on the status of whether an email (for example) was sent to a specific contact: def show_email_status(contact, email) @contact_email = ContactEmail.find(:first, :conditions => {:contact_id => contact.id, :email_id => email.id }) if ! @contact_email.nil? return @contact_email.status end end I realized that I, of course, want to know the status for whether a call was made to a contact as well, so I wrote: def show_call_status(contact, call) @contact_call = ContactCall.find(:first, :conditions => {:contact_id => contact.id, :call_id => call.id }) if ! @contact_call.nil? return @contact_call.status end end I would love to be able to just have a single helper show_status where I can say show_status(contact,call) or show_status(contact,email) and it would know whether to look for the object @contact_call or @contact_email. Yes, it would be easier if it were just @contact_event, but I want to do a small refactoring while I get the program up and running, and this would make the ability to do a history for a given contact much easier. Thanks!

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  • Objective-measures of the expressiveness of programming languages [closed]

    - by Casebash
    I am very interested in the expressiveness of different languages. Everyone who has programmed in multiple languages knows that sometimes a language allows you to express concepts which you can't express in other languages. You can have all kinds of subjective discussion about this, but naturally it would be better to have an objective measure. There do actually exist objective measures. One is Turing-Completeness, which means that a language is capable of generating any output that could be generated by following a sequential set of steps. There are also other lesser levels of expressiveness such as Finite State Automata. Now, except for domain specific languages, pretty much all modern languages are Turing complete. It is therefore natural to ask the following question: Can we can define any other formal measures of expressiveness which are greater than Turing completeness? Now of course we can't define this by considering the output that a program can generate, as Turing machines can already produce the same output that any other program can. But there are definitely different levels in what concepts can be expressed - surely no-one would argue that assembly language is as powerful as a modern object oriented language like Python. You could use your assembly to write a Python interpreter, so clearly any accurate objective measure would have to exclude this possibility. This also causes a problem with trying to define the expressiveness using the minimum number of symbols. How exactly to do so is not clear and indeed appears extremely difficult, but we can't assume that just because we don't know how to solve a problem, that nobody know how to. It is also doesn't really make sense to demand a definition of expressiveness before answering the question - after all the whole point of this question is to obtain such a definition. I think that my explanation will be clear enough for anyone with a strong theoretical background in computer science to understand what I am looking for. If you do have such a background and you disagree, please comment why, but if you don't thats probably why you don't understand the question.

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  • method works fine, until it is called in a function, then UnboundLocalError

    - by user1776100
    I define a method called dist, to calculate the distance between two points which I does it correctly when directly using the method. However, when I get a function to call it to calculate the distance between two points, I get UnboundLocalError: local variable 'minkowski_distance' referenced before assignment edit sorry, I just realised, this function does work. However I have another method calling it that doesn't. I put the last method at the bottom This is the method: class MinkowskiDistance(Distance): def __init__(self, dist_funct_name_str = 'Minkowski distance', p=2): self.p = p def dist(self, obj_a, obj_b): distance_to_power_p=0 p=self.p for i in range(len(obj_a)): distance_to_power_p += abs((obj_a[i]-obj_b[i]))**(p) minkowski_distance = (distance_to_power_p)**(1/p) return minkowski_distance and this is the function: (it basically splits the tuples x and y into their number and string components and calculates the distance between the numeric part of x and y and then the distance between the string parts, then adds them. def total_dist(x, y, p=2, q=2): jacard = QGramDistance(q=q) minkowski = MinkowskiDistance(p=p) x_num = [] x_str = [] y_num = [] y_str = [] #I am spliting each vector into its numerical parts and its string parts so that the distances #of each part can be found, then summed together. for i in range(len(x)): if type(x[i]) == float or type(x[i]) == int: x_num.append(x[i]) y_num.append(y[i]) else: x_str.append(x[i]) y_str.append(y[i]) num_dist = minkowski.dist(x_num,y_num) str_dist = I find using some more steps #I am simply adding the two types of distance to get the total distance: return num_dist + str_dist class NearestNeighbourClustering(Clustering): def __init__(self, data_file, clust_algo_name_str='', strip_header = "no", remove = -1): self.data_file= data_file self.header_strip = strip_header self.remove_column = remove def run_clustering(self, max_dist, p=2, q=2): K = {} #dictionary of clusters data_points = self.read_data_file() K[0]=[data_points[0]] k=0 #I added the first point in the data to the 0th cluster #k = number of clusters minus 1 n = len(data_points) for i in range(1,n): data_point_in_a_cluster = "no" for c in range(k+1): distances_from_i = [total_dist(data_points[i],K[c][j], p=p, q=q) for j in range(len(K[c]))] d = min(distances_from_i) if d <= max_dist: K[c].append(data_points[i]) data_point_in_a_cluster = "yes" if data_point_in_a_cluster == "no": k += 1 K[k]=[data_points[i]] return K

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  • How do you deal with breaking changes in a Rails migration?

    - by Adam Lassek
    Let's say I'm starting out with this model: class Location < ActiveRecord::Base attr_accessible :company_name, :location_name end Now I want to refactor one of the values into an associated model. class CreateCompanies < ActiveRecord::Migration def self.up create_table :companies do |t| t.string :name, :null => false t.timestamps end add_column :locations, :company_id, :integer, :null => false end def self.down drop_table :companies remove_column :locations, :company_id end end class Location < ActiveRecord::Base attr_accessible :location_name belongs_to :company end class Company < ActiveRecord::Base has_many :locations end This all works fine during development, since I'm doing everything a step at a time; but if I try deploying this to my staging environment, I run into trouble. The problem is that since my code has already changed to reflect the migration, it causes the environment to crash when it attempts to run the migration. Has anyone else dealt with this problem? Am I resigned to splitting my deployment up into multiple steps?

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  • Is Maven really flexible?

    - by Dima
    I understand how Maven works with .java files in src/java/main. But may it be used for a more general case? Let us put it more abstract: Suppose I already have some a.exe that read some (not necessarily only .java) sources from directories A1, A2, A3 and puts some files (maybe some are generated .java) to directories B1, B2. I also have some b.exe that currently reads files from B1, B2, B3 and generates something else. Some more similar steps. (A real life problem stands behind). I would like to right POM.xml file so that maven will do this work. Is that possible? I assume that a.exe and b.exe should be warped as maven plugings. Next, in Maven docs I see : <build> <sourceDirectory>${basedir}/src/main/java</sourceDirectory> <scriptSourceDirectory>${basedir}/src/main/scripts</scriptSourceDirectory> <testSourceDirectory>${basedir}/src/test/java</testSourceDirectory> <outputDirectory>${basedir}/target/classes</outputDirectory> <testOutputDirectory>${basedir}/target/test-classes</testOutputDirectory> ... </build> What bothers me is that "sourceDirectory" looks by itself as a hard coded name. Will Maven accept A1 and A2 tags instead?

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