Search Results

Search found 428 results on 18 pages for 'inverse'.

Page 9/18 | < Previous Page | 5 6 7 8 9 10 11 12 13 14 15 16  | Next Page >

• NSFetchedResultsController Crashes When Navigating from One UITableViewController to Another

  - by wgpubs

  In my core data model I have a Person entity that has a "to many" relationship a Course entity (I also have an inverse "to one" relationship from Course to Person). Now I have a subclassed UITableViewController that uses a NSFetchedResultsController to display Person objects which works fine. I have this set up so that when you click on a Person it publishes another subclassed UITableViewController that uses a NSFetchedController as well to display the Courses associated to the person. PROBLEM: I get this exception whenever I click on the Person and attempt to display the Course UITableViewController ... "Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath name not found in entity <NSSQLEntity Course id=2>'" Any ideas on how to resolve or troubleshoot? The code between the two ViewControllers is almost identical except for the NSFetchedResultsController being configured for "Person" entities in one and "Course" entities in another

  Read the article

• NSFetchedResultsController when navigating from one UITableViewController to another ...

  - by wgpubs

  In my core data model I have a Person entity that has a "to many" relationship a Course entity (I also have an inverse "to one" relationship from Course to Person). Now I have a subclassed UITableViewController that uses a NSFetchedResultsController to display Person objects which works fine. I have this set up so that when you click on a Person it publishes another subclassed UITableViewController that uses a NSFetchedController as well to display the Courses associated to the person. PROBLEM: I get this exception whenever I click on the Person and attempt to display the Course UITableViewController ... "Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath name not found in entity '" Any ideas on how to resolve or troubleshoot? The code between the two ViewControllers is almost identical except for the NSFetchedResultsController being configured for "Person" entities in one and "Course" entities in another

  Read the article

• NodeJS and node-mongodb-native

  - by w1nk

  Just getting started with node, and trying to get the mongo driver to work. I've got my connection set up, and oddly I can insert things just fine, however calling find on a collection produces craziness. var db = new mongo.Db('things', new mongo.Server('192.168.2.6',mongo.Connection.DEFAULT_PORT, {}), {}); db.open(function(err, db) { db.collection('things', function(err, collection) { // collection.insert(row); collection.find({}, null, function(err, cursor) { cursor.each(function(err, doc) { sys.puts(sys.inspect(doc,true)); }); }); }); }); If I uncomment the insert and comment out the find, it works a treat. The inverse unfortunately doesn't hold, I receive this error: collection.find({}, null, function(err, cursor) { ^ TypeError: Cannot call method 'find' of null I'm sure I'm doing something silly, but for the life of me I can't find it...

  Read the article

• STFT and ISTFT in Python

  - by endolith

  Is there any form of short-time Fourier transform with corresponding inverse transform built into SciPy or NumPy or whatever? There's the pyplot specgram function in matplotlib, which calls ax.specgram(), which calls mlab.specgram(), which calls _spectral_helper(): #The checks for if y is x are so that we can use the same function to #implement the core of psd(), csd(), and spectrogram() without doing #extra calculations. We return the unaveraged Pxy, freqs, and t. I'm not sure if this can be used to do an STFT and ISTFT, though. Is there anything else, or should I translate something like this?

  Read the article

• fourier transform to transpose key of a wav file

  - by tbischel

  I want to write an app to transpose the key a wav file plays in (for fun, I know there are apps that already do this)... my main understanding of how this might be accomplished is to 1) chop the audio file into very small blocks (say 1/10 a second) 2) run an FFT on each block 3) phase shift the frequency space up or down depending on what key I want 4) use an inverse FFT to return each block to the time domain 5) glue all the blocks together But now I'm wondering if the transformed blocks would no longer be continuous when I try to glue them back together. Are there ideas how I should do this to guarantee continuity, or am I just worrying about nothing?

  Read the article

• Mpi function define

  - by Simone

  I wrote a program in c using MPI (Message Passing Inteface) that compute recursively the inverse of a lower triangular matrix. Every cpu sends 2 submatrices to other two cpus, they compute them and they give them back to the cpu caller. When the cpu caller has its submatrices it has to perform a matrix multiplication. In the recurrence equation the bottle neck is matrix multiplication. I implemented parallel multiplication with mpi in c but i'm not able to embed it into a function. Is it possible? thanks, Simone

  Read the article

• Matrix inversion in OpenCL

  - by buchtak

  Hi, I am trying to accelerate some computations using OpenCL and part of the algorithm consists of inverting a matrix. Is there any open-source library or freely available code to compute lu factorization (lapack dgetrf and dgetri) of matrix or general inversion written in OpenCL or CUDA? The matrix is real and square but doesn't have any other special properties besides that. So far, I've managed to find only basic blas matrix-vector operations implementations on gpu. The matrix is rather small, only about 60-100 rows and cols, so it could be computed faster on cpu, but it's used kinda in the middle of the algorithm, so I would have to transfer it to host, calculate the inverse, and then transfer the result back on the device where it's then used in much larger computations.

  Read the article

• Core data many-to-many relationship - Predicate question

  - by Garry

  In my Core Data model I have two entities: List and Patient. List has an attribute called 'name'. A List can have any number of Patients and each Patient can belong to any number of different lists. I have therefore set a relationship on List called 'patients' that has an inverse to-many relationship to Patient AND a relationship on Patient called 'lists' that has a to-many relationship to List. What I'm struggling to figure out is how to create a Predicate that will select all Patients that belong to a particular List name. How would I go about this? I have never used relationships before in Core Data. Thanks,

  Read the article

• 3D World to Local transformation

  - by Bill Kotsias

  Hello. I am having a real headache trying to set a node's local position to match a given world position. I was given a solution but, AFAICS, it only takes into account orientation and position but NOT scaling : node_new_local_position = node_parent.derivedOrientation().Inverse() * ( world_position_to_match - node_parent.derivedPosition() ); The node in question is a child of node_parent; node_parent local and derived properties (orientation, position and scaling) are known, as well as its full matrix transform. All the positions are 3d vectors; the orientation is a quaternion; the full transform is a 4x4 matrix. Could someone please help me to modify the solution to support scaling in the node hierarchy? Many thanks in advance, Bill

  Read the article

• Interpretation of empty User-agent

  - by Amit Agrawal

  How should I interpret a empty User-agent? I have some custom analytics code and that code has to analyze only human traffic. I have got a working list of User-agents denoting human traffic, and bot traffic, but the empty User-agent is proving to be problematic. And I am getting lots of traffic with empty user agent - 10%. Additionally - I have crafted the human traffic versus bot traffic user agent list by analyzing my current logs. As such I might be missing a lot of entries in there. Is there a well maintained list of user agents denoting bot traffic, OR the inverse a list of user agents denoting human traffic?

  Read the article

• .NET SortedDictionary But Sorted By Values

  - by Michael Covelli

  I need a data structure that acts like a SortedDictionary<int, double> but is sorted based on the values rather than the keys. I need it to take about 1-2 microseconds to add and remove items when we have about 3000 items in the dictionary. My first thought was simply to switch the keys and values in my code. This very nearly works. I can add and remove elements in about 1.2 microseconds in my testing by doing this. But the keys have to be unique in a SortedDictionary so that means that values in my inverse dictionary would have to be unique. And there are some cases where they may not be. Any ideas of something in the .NET libraries already that would work for me?

  Read the article

• Core Data - NSPredicate to filter to-many relationship

  - by Macatomy

  I have 2 entities, Task and List. Each task has a to-one relationship to a List object called "list", and there is an inverse relationship with List, which has a to-many relationship with Task called "tasks". I'm trying to use a fetch request with an NSPredicate to get all the Task objects that belong to a specified List: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"list=%@", theList]; [fetchRequest setPredicate:predicate]; (where "theParent" is a reference to a List object). However this returns no fetched objects. If I take out the predicate, then the objects are returned (so I do know they exist, and by NSLogging theList I know it has Task objects associated with it). Thanks

  Read the article

• Insert new relationship data in core data

  - by michael

  Hoping someone can shed some light on what I might be doing wrong here. Trying to add an "event" to a list of events, represented by a one to many (inverse) relationship: MyEvents <--- Event This is the code: MyEvents *myEvents = (MyEvents *)[NSEntityDescription insertNewObjectForEntityForName:@"MyEvents" inManagedObjectContext:context]; NSLog(@"MYEVENTS: %@", myEvents); NSLog(@"EVENT: %@", event); [myEvents addEventObject:event]; My context is fine, and both the myEvents and event print perfectly valid information. When I try to add the event that I have (which is passed into this view controller, having been retrieved from core data previously) with this code [myEvents addEventObject:event]; It falls over with *** -[NSComparisonPredicate evaluateWithObject:]: message sent to deallocated instance MyEvents and Event are just the default generated code. MyEvents contains only the relationship to event. Thanks.

  Read the article

• Mapping A Sphere To A Cube

  - by petrocket

  There is a special way of mapping a cube to a sphere described here: http://mathproofs.blogspot.com/2005/07/mapping-cube-to-sphere.html It is not your basic "normalize the point and your done" approach and gives a much more evenly spaced mapping. I've tried to do the inverse of the mapping going from sphere coords to cube coords and have been unable to come up the working equations. It's a rather complex system of equations with lots of square roots. Any math geniuses want to take a crack at it? Here's the equations in c++ code: sx = x * sqrtf(1.0f - y * y * 0.5f - z * z * 0.5f + y * y * z * z / 3.0f); sy = y * sqrtf(1.0f - z * z * 0.5f - x * x * 0.5f + z * z * x * x / 3.0f); sz = z * sqrtf(1.0f - x * x * 0.5f - y * y * 0.5f + x * x * y * y / 3.0f); sx,sy,sz are the sphere coords and x,y,z are the cube coords.

  Read the article

• jQuery - change a list of elements to an associative array

  - by Brian M. Hunt

  Given an associative array (of the sort returned by jQuery.serializeArray()) like this: [ { 'name': 'abc', 'value': 'aaa', '__proto__': [Object] }, { 'name': 'def', 'value': 'bbb', '__proto__': [Object] }, { 'name': 'abc', 'value': 'ccc', '__proto__': [Object] } ] How can one convert this, using either jQuery or just javascript, to an associative array of name: [values] like this: { 'abc': ['aaa', 'ccc'], 'def': ['bbb'] } This seems to essentially be the inverse of this question: Build associative array based on values of another associative array... but in Javascript (not PHP). I wasn't able to find this question on Stackoverflow, though I thought it would have been asked. Thank you for reading. Brian

  Read the article

• C#, WPF. Length of string that will fit in a specific width.

  - by Ian

  Hi, I'm sure I'm missing something obvious, I have an area in which I intend to draw text. I know its (the area) height and width. I wish to know how many characters/Words will fit in the width, characters preferably. Second question, If the line is too long I'll want to draw a second line, so I guess I need to get the height of the text as well, including what ever it considers the right vertical padding? I'd also rather like to know the inverse, i.e. how many characters I can fit in a specific width. I assume the fact that WPF isn't constrained to pixels will have some bearing on the answer? Ultimately I'm planning on wrapping text around irregular shaped images embedded in the text. Any pointers in the right direction would be great. Thanks

  Read the article

• NSPredicate by NSManagedObject for many-to-one lookups

  - by niklassaers

  Hi guys, I've got the scenario with two NSManagedObjects, Arm and Person. Between them is a many-to-one relationship Person.arms and inverse Arm.owner. I'd like to write a simple NSPredicate where I've got the NSManagedObject *arm and I'd like to fetch the NSManagedObject *person that this arm belongs to. I could make a textual representation and look for that, but is there a better way where I can look it up by identity? Something like this perhaps? NSEntityDescription *person = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:MOC]; NSPredicate *personPredicate = [NSPredicate predicateWithFormat:@"%@ IN arms", arm]; Cheers Nik

  Read the article

• Invert regexp in vim

  - by Chris J

  There's a few "how do I invert a regexp" questions here on stackoverflow, but I can't find one for vim (if it does exist, by goggle-fu is lacking today). In essence I want to match all non-printable characters and delete them. I could write a short script, or drop to a shell and use tr or something similar to delete, but a vim solution would be dandy :-) Vim has the atom \p to match printable characters, however trying to do this :s/[^\p]//g to match the inverse failed and just left me with every 'p' in the file. I've seen the (?!xxx) sequence in other questions, and vim seems to not recognise this sequence. I've not found seen an atom for non-printable chars. In the interim, I'm going to drop to external tools, but if anyone's got any trick up their sleeve to do this, it'd be welcome :-) Ta!

  Read the article

• How to make safe cast using generics in C#?

  - by TN

  I want to implement a generic method on a generic class which would allow to cast safely, see example: public class Foo<T> : IEnumerable<T> { ... public IEnumerable<R> SafeCast<R>() where T : R { return this.Select(item => (R)item); } } However, the compiler tells me that Foo<T>.SafeCast<R>() does not define parameter 'T'. I understand this message that I cannot specify a constraint on T in the method since it is not defined in the method. But how can I specify an inverse constraint?

  Read the article

• Replacement background image not showing when using GreaseMonkey

  - by Dave C

  I'm trying to use GreaseMonkey to replace the background image of a DIV on bing.com. It's a pretty straightforward call to GM_addstyle: GM_addStyle(".sw_logo " +"{background:url('http://www.kpao.org/blog/kpao-bing-logo-inverse.png') " +"no-repeat 21px 7px transparent}"); However, the image doesn't show up. It's clearly visible in Firebug, and as I twiddle with the CSS in Firebug, I can get it to show up. But it doesn't stay. Any thoughts on why? Maybe it's a bug, but then maybe I'm missing something obvious. Thanks!

  Read the article

• Racket regular-expression matching

  - by Inaimathi

  I'm trying to create a regex that matches the inverse of a certain string type (so, strings not ending in ".js", for example). According to the documentation, that should be the expression #rx"(?!\\.js$)", but it doesn't seem to work. To test it out, I have this function: (define (match-test regex) (map (lambda (text) (regexp-match? regex text)) '("foo.js" "bar.css" "baz.html" "mumble.gif" "foobar"))) (match-test #rx"\\.js$") returns (#t #f #f #f #f) as expected, but (match-test #rx"(?!\\.js$)") returns (#t #t #t #t #t), where I would expect (#f #t #t #t #t). What am I doing wrong, and how do I actually get a regex in Racket to express the idea "match anything which does not contain [x]"?

  Read the article

• Getting websites to detect our mobile browser

  - by Chromatix

  I've been asked to find out a sensible way to make the majority of popular websites detect our browser - which is functionally complete, but is running on rather constrained hardware - as a "mobile" browser. The idea is that the heaviest popular websites seem to have mobile versions, which render much faster and fit better on the screen. I've looked at the inverse question, which tells me that there isn't an obvious standard way of doing it - http://www.brainhandles.com/techno-thoughts/detecting-mobile-browsers is a case in point. This is borne out by looking at a variety of User-Agent strings from popular mobile and desktop browsers. So far the best idea we can come up with is to add "Mobile" to the string somewhere, since this is the main visible difference between Safari for iPad/iPhone and for Windows/Mac. Does anyone have a better idea?

  Read the article

• PHP Inverting content adding (sorting)

  - by Adrian

  Hello, I have this code which will include "template.php" file from inside each of these folders: "content/templates/id1", "content/templates/id2", "content/templates/id3" etc. etc. $page_file = basename(__FILE__, ".php"); require("content/" . $page_file . "/content.php"); $iterator = new RecursiveIteratorIterator( new RecursiveDirectoryIterator($page_path), RecursiveIteratorIterator::SELF_FIRST); foreach($iterator as $file) { if($file->isDir()) { include strtoupper($file . '/template.php'); } } This code works pretty well, the problem is I want to inverse the content adding, meaning that I want first "content/templates/id9/template.php" included before "id8/template.php" and so on till the first.. How can I do this by modifying the code above? A million thanks!

  Read the article

• Where can I find simple beta cdf implementation.

  - by Gacek

  I need to use beta distribution and inverse beta distribution in my project. There is quite good but complicated implementation in GSL, but I don't want to use such a big library only to get one function. I would like to either, implement it on my own or link some simple library. Do you know any sources that could help me? I'm looking for any books/articles about numerical approximation of beta PDF, libraries where it could be implemented. Any other suggestions would be also appreciated. Any programming language, but C++/C# preffered.

  Read the article

• Nhibernate: one-to-many, based on multiple keys?

  - by e36M3

  Lets assume I have two tables Table tA ID ID2 SomeColumns Table tB ID ID2 SomeOtherColumns I am looking to create a Object let's call it ObjectA (based on tA), that will have a one-to-many relationship to ObjectB (based on tB). In my example however, I need to use the combination of ID and ID2 as the foreign key. If I was writing SQL it would look like this: select tB.* from tA, tB where tA.ID = tB.ID and tA.ID2 = tB.ID2; I know that for each ID/ID2 combination in tA I should have many rows in tB, therefor I know it's a one-to-many combination. Clearly the below set is not sufficient for such mapping as it only takes one key into account. <set name="A2" table="A2" generic="true" inverse="true" > <key column="ID" /> <one-to-many class="A2" /> </set> Thanks!

  Read the article

< Previous Page | 5 6 7 8 9 10 11 12 13 14 15 16  | Next Page >