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  • How do I compute the approximate entropy of a bit string?

    - by dreeves
    Is there a standard way to do this? Googling -- "approximate entropy" bits -- uncovers multiple academic papers but I'd like to just find a chunk of pseudocode defining the approximate entropy for a given bit string of arbitrary length. (In case this is easier said than done and it depends on the application, my application involves 16,320 bits of encrypted data (cyphertext). But encrypted as a puzzle and not meant to be impossible to crack. I thought I'd first check the entropy but couldn't easily find a good definition of such. So it seemed like a question that ought to be on StackOverflow! Ideas for where to begin with de-cyphering 16k random-seeming bits are also welcome...) See also this related question: http://stackoverflow.com/questions/510412/what-is-the-computer-science-definition-of-entropy

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  • Problem with entityForName & ManagedObjectContext when extending tutorial material

    - by Martin KS
    Afternoon all, I tried to add a second data entity to the persistent store in the (locations) coredata tutorial code, and then access this in a new view. I think that I've followed the tutorial, and checked that I'm doing a clean build etc, but can't see what to change to prevent it crashing. I'm afraid I'm at my wits end with this one, and can't seem to find the step that I've missed. I've pasted the header and code files below, please let me know if I need to share any more of the code. The crash seems to happen on the line: NSEntityDescription *entity = [NSEntityDescription entityForName:@"Album" inManagedObjectContext:[self managedObjectContext]]; There is one other line in the code that refers to galleryviewcontroller at the moment, and that's in the main application delegate: galleryViewController.managedObjectContext = [self managedObjectContext]; GalleryViewController.h #import <UIKit/UIKit.h> @interface GalleryViewController : UIViewController { NSManagedObjectContext *managedObjectContext; int rowNumber; IBOutlet UILabel *lblMessage; UIBarButtonItem *addButton; NSMutableArray *imagesArray; } @property (readwrite) int rowNumber; @property (nonatomic,retain) UILabel *lblMessage; @property (nonatomic,retain) NSMutableArray *imagesArray; @property (nonatomic, retain) NSManagedObjectContext *managedObjectContext; @property (nonatomic, retain) UIBarButtonItem *addButton; -(void)updateRowNumber:(int)theIndex; -(void)addImage; @end GalleryViewController.m #import "RootViewController.h" #import "LocationsAppDelegate.h" #import "Album.h" #import "GalleryViewController.h" #import "Image.h" @implementation GalleryViewController @synthesize lblMessage,rowNumber,addButton,managedObjectContext; @synthesize imagesArray; /* // The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad. - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) { // Custom initialization } return self; } */ -(void)updateRowNumber:(int)theIndex{ rowNumber=theIndex; LocationsAppDelegate *mainDelegate =(LocationsAppDelegate *)[[UIApplication sharedApplication] delegate]; Album *anAlbum = [mainDelegate.albumsArray objectAtIndex:rowNumber]; lblMessage.text = anAlbum.uniqueAlbumIdentifier; } // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addImage)]; addButton.enabled = YES; self.navigationItem.rightBarButtonItem = addButton; /* Found this in another answer, adding it to the code didn't help. if (managedObjectContext == nil) { managedObjectContext = [[[UIApplication sharedApplication] delegate] managedObjectContext]; } */ NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Album" inManagedObjectContext:[self managedObjectContext]]; [request setEntity:entity]; // Order the albums by creation date, most recent first. NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"imagePath" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptor release]; [sortDescriptors release]; // Execute the fetch -- create a mutable copy of the result. NSError *error = nil; NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy]; if (mutableFetchResults == nil) { // Handle the error. } [self setImagesArray:mutableFetchResults]; int a = 5; int b = 10; for( int i=0; i<[imagesArray count]; i++ ) { if( a == 325 ) { a = 5; b += 70; } UIImageView *any = [[UIImageView alloc] initWithFrame:CGRectMake(a,b,70,60)]; any.image = [imagesArray objectAtIndex:i]; any.tag = i; [self.view addSubview:any]; [any release]; a += 80; } } -(void)addImage{ NSString *msg = [NSString stringWithFormat:@"%i",rowNumber]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Add image to" message:msg delegate:self cancelButtonTitle:@"No" otherButtonTitles:@"Yes", nil]; [alert show]; [alert release]; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { [super viewDidUnload]; } - (void)dealloc { [lblMessage release]; [managedObjectContext release]; [super dealloc]; } @end

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  • value of type 'string' cannot be converted to 'Devart.data.postgresql.PgSqlParameter'

    - by hector
    The following is my PostgreSQL table structure and the vb.net code to insert into the tables.Using Devart's Component For PostgreSQL Connect table gtab83 CREATE TABLE gtab83 ( orderid integer NOT NULL DEFAULT nextval('seq_gtab83_id'::regclass), acid integer, slno integer, orderdte date ) table gtab84 CREATE TABLE gtab84 ( orderdetid integer DEFAULT nextval('seq_gtab84_id'::regclass), productid integer, qty integer, orderid integer ) Code to insert into the above tables is below '1.)INSERT INTO gtab83(orderid,acid, slno, orderdte) VALUES (?, ?, ?); '2.)INSERT INTO gtab84(orderdetid,productid, qty, orderid) VALUES (?, ?, ?); Try Dim cmd As PgSqlCommand = New PgSqlCommand("", Myconnstr) cmd.CommandText = _ "INSERT INTO GTAB83(ACID,SLNO,ORDERDTE)" & _ "VALUES " & _ "(@acid,@slno,@orderdte);" Dim paramAcid As PgSqlParameter = New PgSqlParameter("@acid", PgSqlType.Int, 0) Dim paramSlno As PgSqlParameter = New PgSqlParameter("@slno", PgSqlType.Int, 0) Dim paramOrderdte As PgSqlParameter = New PgSqlParameter("@orderdte", PgSqlType.Date, 0) paramAcid = cboCust.SelectedValue paramSlno = txtOrderNO.Text #ERROR# paramOrderdte = (txtDate.Text, "yyyy-MM-dd") #ERROR# Catch ex As Exception End Try ERROR : value of type 'string' cannot be converted to 'Devart.data.postgresql.PgSqlParameter'

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  • Writing temporary data from R

    - by Shane
    I want to write some temporary data to disk in an R package, and I want to be sure that it can run on every OS without assuming the user has admin rights. Is there an existing R function that can provide a path to a temporary directory on all major OS's? Or a way to reference a user's home directory? Otherwise, I was thinking of trying this: Sys.getenv("temp") I presume that I can't expect people to have write access to their R locations, otherwise I could reference a path within the package directory: .find.package("package.name").

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  • Functionality in a Data Access Layer formed by a dbml

    - by Younes
    I got a Data Access Layer that's being formed by one DBML in which i just include all object I need. Is it necessary to write more functionality in this dbml or can I just use the dbml as my DAL? I ask this because I am currently writing functionality to, for example, get all Articles from a Table in the Business Logic Layer. So I'm kind of lost now. What kind of examples can be given so that it's clear to me what to put in the Business Layer.

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  • Dynamically assigning properties on a non data bound ASP.NET control

    - by thinknow
    For example, let's say I have a HyperLink: <asp:HyperLink runat="server" Text="Foo" NavigateUrl="foo.aspx" /> How can I set the NavigateUrl on the server side, without having to go the code-behind? This doesn't work of course: <asp:HyperLink runat="server" Text="Foo" NavigateUrl="<%= urlString %>" /> (where urlString might be a string I created earlier in the page) And this doesn't work because the HyperLink is not within a data bound control: <asp:HyperLink runat="server" Text="Foo" NavigateUrl='<%# urlString %>' /> I guess I could just use a standard anchor element: <a href="<%= urlString %>">Foo</a> But I'd rather not mix up HTML and ASP.NET controls, and it would be handy to be able to do this for other controls. Surely there must be a way?

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  • Transform data in FMPXMLRESULT grammar into a "Content Standard for Digital Geospatial Metadata (CS

    - by Andrew Igbo
    I have a problem in FileMaker; I wish to link the METADATA element/FIELD element “NAME” attribute to its corresponding data in the RESULTSET element/COL element. However, I also wish to map the METADATA element/FIELD element “NAME” to "Content Standard for Digital Geospatial Metadata (CSDGM)" metadata elements Sample XML Metadata Record with CSDGM Essential Elements Louisiana State University Coastal Studies Institute 20010907 Geomorphology and Processes of Land Loss in Coastal Louisiana, 1932 – 1990 A raster GIS file that identifies the land loss process and geomorphology associated with each 12.5 meter pixel of land loss between 1932 and 1990. Land loss processes are organized into a hierarchical classification system that includes subclasses for erosion, submergence, direct removal, and undetermined. Land loss geomorphology is organized into a hierarchical classification system that includes subclasses for both shoreline and interior loss. The objective of the study was to determine the land loss geomorphologies associated with specific processes of land loss in coastal Louisiana.

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  • Continuous Integration with Oracle Products

    - by Lee Gathercole
    Hi, I'm currently working on a Datawarehouse project using an Oracle Database, Oracle Data Integrator, Oracle Warehouse Builder and some Jython thrown in for good measure. All of which is held within TFS. My background is .net and prior to this project was seeing a lot of promise in CI. I'm not suggesting that the testing element of CI is feasible in this instance, but I would like to implement a stable deployment strategy. What I'm trying to understand is whether or not I can build some NANT scripts that will allow me to deploy ODI\OWB\Oracle DB code to any given environment at any point. Has anyone tried this before? Are there more appropriate tools out there that lends themselves better to this sort of toolset? Am I just a crazy horse to be evening contemplating this? Any view would be greatly appreciated. Thanks Lee

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  • How to validate Data Annotations with a MetaData class

    - by Micah
    I'm trying to validate a class using Data Annotations but with a metadata class. [MetadataType(typeof(TestMetaData))] public class Test { public string Prop { get; set; } internal class TestMetaData { [Required] public string Prop { get; set; } } } [Test] [ExpectedException(typeof(ValidationException))] public void TestIt() { var invalidObject = new Test(); var context = new ValidationContext(invalidObject, null, null); context.MemberName = "Prop"; Validator.ValidateProperty(invalidObject.Prop, context); } The test fails. If I ditch the metadata class and just decorated the property on the actual class it works fine. WTH am I doing wrong? This is putting me on the verge of insanity. Please help.

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  • Python: Plot some data (matplotlib) without GIL

    - by BandGap
    Hello all, my problem is the GIL of course. While I'm analysing data it would be nice to present some plots in between (so it's not too boring waiting for results) But the GIL prevents this (and this is bringing me to the point of asking myself if Python was such a good idea in the first place). I can only display the plot, wait till the user closes it and commence calculations after that. A waste of time obviously. I already tried the subprocess and multiprocessing modules but can't seem to get them to work. Any thoughts on this one? Thanks

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  • jQuery plugin options: required, optional, inaccessible

    - by Trevor Hartman
    I'm curious how to specify options to a jQuery plugin in a way that some are required, some are optionally overridden, and some can't be touched. I started off with the usual: jQuery.fn.plugin = function (options){ var defaults = { username: "", posts:10, api: "http://myapi.com" } var settings = jQuery.extend({}, defaults, options); } Let's say I want username to be required, posts is optional (defaults to 10) and you (you being the user of the plugin) can't change api, even if they try. Ideally, they'd all still be in the same data structure instead of being split into separate objects. Ideas?

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  • Displaying Google Calendar event data on FullCalendar

    - by aurealus
    I am using Google Calendar as a storage engine for a calendar system I am building, however, I am using a single Google user account with multiple calendars, i.e. each user on my system has their own calendar within the one user account. I'm able to create a calendar per user just fine, but I would like to have FullCalendar retrieve the events for display purposes, without manually getting the magic cookie url from Google Calendar settings. I would like to be able to retrieve it programmatically or 'proxy' the feed via an authenticated call to get event data that I'm doing in Django. $('#calendar').fullCalendar({ events: $.fullCalendar.gcalFeed( "http://www.google.com/calendar_url/" <-- or /my/event/feed/url ) });

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  • Reading data from a socket, considerations for robustness and security

    - by w.brian
    I am writing a socket server that will implement small portions of the HTTP and the WebSocket protocol, and I'm wondering what I need to take into consideration in order to make it robust/secure. This is my first time writing a socket-based application so please excuse me if any of my questions are particularly naive. Here goes: Is it wrong to assume that you've received an entire HTTP request (WebSocket request, etc) if you've read all data available from the socket? Likewise, is it wrong to assume you've only received one request? Is TCP responsible for making sure I'm getting the "message" all at once as sent by the client? Or do I have to manually detect the beginning and end of each "message" for whatever protocol I'm implementing? Regarding security: What, in general, should I be aware of? Are there any common pitfalls when implementing something like this? As always, any feedback is greatly appreciated.

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  • Correct way to Convert 16bit PCM Wave data to float

    - by fredley
    I have a wave file in 16bit PCM form. I've got the raw data in a byte[] and a method for extracting samples, and I need them in float format, i.e. a float[] to do a Fourier Transform. Here's my code, does this look right? I'm working on Android so javax.sound.sampled etc. is not available. private static short getSample(byte[] buffer, int position) { return (short) (((buffer[position + 1] & 0xff) << 8) | (buffer[position] & 0xff)); } ... float[] samples = new float[samplesLength]; for (int i = 0;i<input.length/2;i+=2){ samples[i/2] = (float)getSample(input,i) / (float)Short.MAX_VALUE; }

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  • Returning a complex data type from arguments with Rhino Mocks

    - by Joseph
    I'm trying to set up a stub with Rhino Mocks which returns a value based on what the parameter of the argument that is passed in. Example: //Arrange var car = new Car(); var provider= MockRepository.GenerateStub<IDataProvider>(); provider.Stub( x => x.GetWheelsWithSize(Arg<int>.Is.Anything)) .Return(new List<IWheel> { new Wheel { Size = ?, Make = Make.Michelin }, new Wheel { Size = ?, Make = Make.Firestone } }); car.Provider = provider; //Act car.ReplaceTires(); //Assert that the right tire size was used when replacing the tires The problem is that I want Size to be whatever was passed into the method, because I'm actually asserting later that the wheels are the right size. This is not to prove that the data provider works obviously since I stubbed it, but rather to prove that the correct size was passed in. How can I do this?

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  • Android Stream Data Over Wifi?

    - by Neb
    Im trying to make an app for android that will stream the data of the accelerometer to be used as a game controller on my pc over a local wifi connection. Is it possible to make some kind of wifi stream of the accelerometer values in the android app and then make the pc somehow 'read' this stream? Or would it just be better for the pc to make endless calls to the phone getting the newest accelerometer values from a local android server? It would also have to send commands from the phone such as 'button1 pressed', 'button1 released'.

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  • [PHP] Sorting data in an array

    - by kwokwai
    Hi all, I got an array which has 7 types of fruit: $fruits = array( "lemon", "orange", "banana", "apple", "cherry", "apricot", "Blueberry" ); I don't know how to print out the data in a way that the outcome will like this: <A> Apple, Apricot (Note that Apricot is followed by Apple in alphabetic order) <B> Banana <C> Cherry <L> Lemon <O> Orange I am sorry that the question may be a bit difficult. But please kindly help if you could.

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  • Getting data back from database after an ajax post submit

    - by sslepian
    I've got a web page where the user can add a new item to a category and that item is saved to the database. However, the ID of the item is an identity value for the database table, so I don't know what the ID will be, and I need this ID so that the user can edit the item later. I'm using ajax to make a POST submit: $.ajax({ url: 'TumourGroup/CreateSub', type: "POST", data: {'pos': index, 'text': text } }); This is linked to an MVC model with three fields, ID, pos, and text. Is there a way for me to get the ID that's generated on POST submit by having CreateSub(int index, string text) return something?

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  • C++: A variation of priority queue

    - by Helltone
    I need some kind of priority queue to store pairs <key, value>. Values are unique, but keys aren't. I will be performing the following operations (most common first): random insertion; retrieving (and removing) all elements with the least key. random removal (by value); I can't use std::priority_queue because it only supports removing the head. For now, I'm using an unsorted std::list. Insertion is performed by just pushing new elements to the back (O(1)). Operation 2 sorts the list with std::sort (O(N*logN)), before performing the actual retrieval. Removal, however, is O(n), which is a bit expensive. Any idea of a better data structure?

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  • Cyclic References and WCF

    - by Kunal
    I have generated my POCO entities using POCO Generator, I have more than 150+ tables in my database. I am sharing POCO entities all across the application layers including the client. I have disabled both LazyLoading and ProxyCreation in my context.I am using WCF on top of my data access and business layer. Now, When I return a poco entity to my client, I get an error saying "Underlying connection was closed" I enabled WCF tracing and found the exact error : Contains cycles and cannot be serialized if reference tracking is disabled. I Looked at MSDN and found solutions like setting IsReference=true in the DataContract method atttribute but I am not decorating my POCO classes with DataContracts and I assume there is no need of it as well. I won't be calling that as a POCO if I decorate a class with DataContract attribute Then, I found solutions like applying custom attribute [CyclicReferenceAware] over my ServiceContracts.That did work but I wanted to throw this question to community to see how other people managed this and also why Microsoft didn't give built in support for figuring out cyclic references while serializing POCO classes

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  • Beginner question: What is binding?

    - by JDelage
    Hi, I was trying to understand the difference between early and late binding, and in the process realized that the concept of binding is nebulous to me. I think I understand that it relates to the way data-as-a-word-of-memory is linked to type-as-a-set-of-language-features but I am not sure those are the right concepts. Also, how does understanding this deeply help people become better programmers? Please note: This question is not "what is late v. early binding" or "what are the trade-offs between the 2". Those already exist here. Thanks, JDelage

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  • knockout bind text label to dropdown value selected option text

    - by Adam Levitt
    Is there a simple way to bind the textbox of a div to change based on the text value of the selected option in a dropdown on the same page? <div data-bind="text: dropdownValue"></div> <select> <option value="1">Value1</option> <option value="2">Value2</option> </select> Please note, I don't want to put the values into the select element using javascript. I'd like to bind to the value straight from the HTML. I can also include jQuery to make it work.

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  • R counting the occurance of similar rows of data frame

    - by Matt
    I have data in the following format called DF (this is just a made up simplified sample): eval.num, eval.count, fitness, fitness.mean, green.h.0, green.v.0, offset.0 random 1 1 1500 1500 100 120 40 232342 2 2 1000 1250 100 120 40 11843 3 3 1250 1250 100 120 40 981340234 4 4 1000 1187.5 100 120 40 4363453 5 1 2000 2000 200 100 40 345902 6 1 3000 3000 150 90 10 943 7 1 2000 2000 90 90 100 9304358 8 2 1800 1900 90 90 100 284333 However, the eval.count column is incorrect and I need to fix it. It should report the number of rows with the same values for (green.h.0, green.v.0, and offset.0) by only looking at the previous rows. The example above uses the expected values, but assume they are incorrect. How can I add a new column (say "count") which will count all previous rows which have the same values of the specified variables? I have gotten help on a similar problem of just selecting all rows with the same values for specified columns, so I supposed I could just write a loop around that, but it seems inefficient to me.

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  • Entity Framework: Data Centric vs. Object Centric

    - by Eric J.
    I'm having a look at Entity Framework and everything I'm reading takes a data centric approach to explaining EF. By that I mean that the fundamental relationships of the system are first defined in the database and objects are generated that reflect those relationships. Examples Quickstart (Entity Framework) Using Entity Framework entities as business objects? The EF documentation implies that it's not necessary to start from the database layer, e.g. Developers can work with a consistent application object model that can be mapped to various storage schemas When designing a new system (simplified version), I tend to first create a class model, then generate business objects from the model, code business layer stuff that can't be generated, and then worry about persistence (or rather work with a DBA and let him worry about the most efficient persistence strategy). That object centric approach is well supported by ORM technologies such as (n)Hibernate. Is there a reasonable path to an object centric approach with EF? Will I be swimming upstream going that route? Any good starting points?

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  • Smoothing Small Data Set With Second Order Quadratic Curve

    - by Rev316
    I'm doing some specific signal analysis, and I am in need of a method that would smooth out a given bell-shaped distribution curve. A running average approach isn't producing the results I desire. I want to keep the min/max, and general shape of my fitted curve intact, but resolve the inconsistencies in sampling. In short: if given a set of data that models a simple quadratic curve, what statistical smoothing method would you recommend? If possible, please reference an implementation, library, or framework. Thanks SO!

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