Search Results

Search found 9193 results on 368 pages for 'batcher sort'.

Page 217/368 | < Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >

• How do I design a cryptographic hash function?

  - by Eyal

  After reading the following about why one-way hash functions are one-way, I would like to know how to design a hash function. http://stackoverflow.com/questions/1038307/help-me-better-understand-cryptographic-hash-functions/1047106#1047106 Before everyone gets on my case: Yes, I know that it's a bad idea to not use a proven and tested hash function. I would still like to know how it's done. I'm familiar with Feistel-network ciphers but those are necessarily reversible, horrible for a cryptographic hash. Is there some sort of construction that is well-used in cryptographic hashing? Something that makes it very one-way?

  Read the article

• Problem with datagridvieew in vb.net

  - by user225269

  I'm trying to add a datagridview in vb.net, but it does not allow me to change the connection string or the database that should be imported to connect to it. The only thing that I'm seeing is the previous ms sql database that I connected with datagridview and everytime I click the new connection, the window closes and it leaves me with the datagridview with the previous connection that I have. And its not applicable because, now I want to connect it with mysql. Not ms sql. Its some sort of a cache like feature in vb.net, how do I get rid of it. so that I can add the new connection for mysql? Do I need to reinstall visual studio 2008?

  Read the article

• Connect to an elevated COM server from a non-elevated process

  - by JS Bangs

  We have a program which launches a child process that hosts a local COM server, which for various reasons must be launched elevated. Everything works fine so long as both the parent and the child process are elevated. However, we also want to run when the parent process is non-elevated. Launching the child process results in a UAC dialog (which is acceptable), and the child appears to start correctly and successfully calls CoRegisterClassObject. However, the parent process gets REGDB_E_CLASSNOTREG when calling CoCreateInstance with the same CLSID. I assume this is some sort of permissions issue. How can I register my class in the elevated server to allow it to be called from a non-elevated process.

  Read the article

• What database works well with 200+GB of data?

  - by taw

  I've been using mysql (with innodb; on Amazon rds) because it's sort of universal default, but it's been ridiculously under-performing, and tweaking it only delays the inevitable. The data is mostly relatively short (<1kB of bytes each) blobs information about 100Ms of urls. There is (or should be, mysql cannot seem to handle it) very high amount of insert / update / retrieve but few complex queries - not that complex queries wouldn't be useful, but because mysql is so slow that it's far faster to get the data out, process it locally, and cache the results somewhere. I can keep tweaking mysql and throwing more hardware at it, but it seems increasingly futile. So what are the options? SQL/relational model/etc. optional - anything will do as long as it's fast, networked, and language-independent.

  Read the article

• CakePHP: How do I order results based on a 2-level deep association model?

  - by KcYxA

  I'm hoping I won't need to resort to custom queries. A related question would be: how do I retrieve data so that if an associated model is empty, no record is retrieved at all, as opposed to an empty array for an associated model? As an oversimplified example, say I have the following models: City -- Street -- House How do I sort City results by House numbers? How do I retrieve City restuls that have at least one House in it? I don't want a record with a city name and details and an empty House array as it messes up pagination results. CakePHP retrieves House records belonging to the Street in a separate query, so putting somthing like 'House.number DESC' into the 'order' field of the search query returns a 'field does not exist' error. Any ideas?

  Read the article

• SQL Server ORDER BY/WHERE with nested select

  - by Echilon

  I'm trying to get SQL Server to order by a column from a nested select. I know this isn't the best way of doing this but it needs to be done. I have two tables, Bookings and BookingItems. BookingItems contains StartDate and EndDate fields, and there can be multiple BookingItems on a Booking. I need to find the earliest startdate and latest end date from BookingItems, then filter and sort by these values. I've tried with a nested select, but when I try to use one of the selected columns in a WHERE or ORDER BY, I get an "Invalid Column Name". SELECT b.*, (SELECT COUNT(*) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS TotalRooms, (SELECT MIN(i.StartDate) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS StartDate, (SELECT MAX(i.EndDate) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS EndDate FROM bookings b LEFT JOIN customers c ON b.CustomerID = c.CustomerID WHERE StartDate >= '2010-01-01' Am I missing something about SQL ordering? I'm using SQL Server 2008.

  Read the article

• Setting a property value on each of the results in a FetchedResults set

  - by RickiG

  Hi On my Core Data Entity "Book" i have a boolean property, 'wasViewed' (NSNumber numberWithBool) that tells me if the Book was "viewed". I would like to implement a sort of "reset" this property for all my NSManagedObjects "Book". So that I can set them all to NO between sessions. I use an NSPredicate to retrieve all the Books like this: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"wasViewed == %@", [NSNumber numberWithBool:YES]]; // code for setting entity, request etc... NSMutableArray *mutableFetchResults = [[[managedObjectContext executeFetchRequest:request error:&error] mutableCopy] autorelease]; This is working just fine, however, now I need to set up a loop, go through each Book object, something like this: for(Book *b in mutableFetchResults) { [b setWasViewed:NO] } Is there a way to perform an action on each element that fits the predicate instead of retrieving it? So instead of executeFetchRequest on a managedObjectContext it could be executeOperationOnFetchRequestResults or something along those lines. Thanks for any input given:)

  Read the article

• Geocode multiple addresses

  - by ace2600

  I need to geocode around 200 addresses per request and do around 3,000 request per day. I will be doing this server side using PHP. I have looked at http://stackoverflow.com/questions/98449/how-to-convert-an-address-to-a-latlon, but could not find a way for either Google Maps HTTP Request API or the Yahoo Geocoding REST API (cannot use JavaScript as this is server side) to send multiple addresses. I will be primarily using this to sort addresses based on the coordinates and if the API supports, fill in any missing data for each address. The addresses will be in the United States only. The addresses to geocode will be from user input, so be free form, like "street address, postal code", or "city, state", etc. Accuracy is not too important for the coordinates, say within five hundred feet or so. Is there a free API to handle this? Is there a way to get Yahoo or Google to do multiple locations in a request?

  Read the article

• Filter user input (paragraph) for links + smileys

  - by Alec Smart

  Hello, I am looking at some sort of existing filter which can sanitize the user input to avoid XSS. Probably I can use htmlspecialchars for that. But at the same time I want to be able to parse all links (should match a.com, www.a.com and http://www.a.com and if it is http://www.aaaaaaaaaaaaaaaaaaaaaaaaaa.com then it should display it as aaa..a.com), e-mails and smileys. I am wondering what is the best way to go about it. I am currently using a php function with some regex, but many times the regex simply fails (because of link recognition is incorrect etc.). I want something very similar to the parser used during Google Chat (even a.com works). Thank you for your time.

  Read the article

• How do I order by foreign attribute for belongs_to refernece where there are 2 keys to foreign table

  - by Will

  I have a Model which has a belongs_to association with another Model as follows class Article belongs_to :author, :class_name => "User" end If I wanted to find all articles for a particular genre ordered by author I would do something like the following articles = Article.all(:includes => [:author], :order => "users.name") However if Article happens to have two references to User how can I sort on :author? class Article belongs_to :editor, :class_name => "User" belongs_to :author, :class_name => "User" end I have tried articles = Article.all(:includes => [:author], :order => "users.name") #=> incorrect results articles = Article.all(:includes => [:author], :order => "authors.name") #=> Exception Thrown

  Read the article

• Access Edit Mode Values of BindingSource Control

  - by Christopher Edwards

  I have a BindingSource control (http://msdn.microsoft.com/en-us/library/system.windows.forms.bindingsource.aspx) with a datasource of a (single) Linq object. If I change any of the properties of the underlying Linq-to-Sql object then all the other changes on the bound controls on the form are lost. Does anyone now why and how I work around it? I don't want to call EndEdit because this will commit the changes to the underlying object. I think this might be because my underlying object linq-to-sql object does not implement IEditableObject so the potental new values for the object fields are sort of stored in the forms controls. Can anyone either clarify what is going on and/or suggest a work around. Thanks!

  Read the article

• Is there a SQL Server error numbers C# wrapper anyone knows of?

  - by Mr Grok

  I really want to do something useful when a PK violation occurs but I hate trapping error numbers... they just don't read right without comments (they're certainly not self documenting). I know I can find all the potential error numbers at SQL Server books online but I really want to be able to pass the error number to some helper class or look it up against a Dictionary of some sort rather than have non-descript err numbers everywhere. Has anyone got / seen any code anywhere that encapsulates the SQL Server Error numbers in this way as I don't want to re-invent the wheel (or I'm lazy maybe).

  Read the article

• Statement hierarchy in programming languages

  - by sudo

  I quickly wrote an interpreter for some sort of experimental programing language i came up with, in PHP (yes, in PHP). The language itself doesn't have anything really special, I just wanted to give it a try. I got the basic things working (Hello World, input to output, string manipulation, arithmetics) but I'm getting stuck with the management of blocks and grouped statements. What I mean is: PHP and most other languages let you do this: ((2+2)*(8+2)+2), of course not only with mathematical computations. My program structure currently consists of a multidimensional array built like this: ID => Type (Identifier, String, Int, Newline, EOF, Comma, ...) Contents (If identifier, int or string) How could I allow statements to be executed in a defined order like in the PHP example above?

  Read the article

• Is it possible to create thread-safe collections without locks?

  - by Andrey

  This is pure just for interest question, any sort of questions are welcome. So is it possible to create thread-safe collections without any locks? By locks I mean any thread synchronization mechanisms, including Mutex, Semaphore, and even Interlocked, all of them. Is it possible at user level, without calling system functions? Ok, may be implementation is not effective, i am interested in theoretical possibility. If not what is the minimum means to do it? EDIT: Why immutable collections don't work. This of class Stack with methods Add that returns another Stack. Now here is program: Stack stack = new ...; ThreadedMethod() { loop { //Do the loop stack = stack.Add(element); } } this expression stack = stack.Add(element) is not atomic, and you can overwrite new stack from other thread. Thanks, Andrey

  Read the article

• How to debug CSS/Javascript hover issues

  - by Jason Creighton

  I often find myself wanting to debug CSS layout issues that involve DOM changes caused by Javascript in reaction to a hover event or different CSS rules applying due to the :hover selector. Normally, I'd use Firebug to inspect the element that's giving me trouble and see what its CSS properties were, and where those properties come from. However, when hovering is involved, it becomes impossible, because as soon as you move your mouse down to the Firebug panel, the elements you're interested in are no longer hovered, the CSS rules that apply are different, and (in the case of JS hovers) the DOM is changed. Is there any way I can "freeze" the state of the DOM and application of :hover in order to inspect the DOM as it was during a hover event? Any other ideas on how to debug this sort of issue are welcome, of course.

  Read the article

• Getting error on inserting tuple values in postgreSQL table using python

  - by rahman.bd

  Hello, I want to keep last.fm's user recent music tracks list to postgresql database table using pylast interface.But when I tried to insert values to the table it shows errors.Code example: for i, artist in enumerate(recent_tracks): for key in sorted(artist): cur.execute(""" INSERT INTO u_recent_track(Playback_date,Time_stamp,Track) VALUES (%s,%s)""", (key, artist[key])) conn.commit() cur.execute("SELECT * FROM u_recent_track;") cur.fetchone() for row in cur: print ' '.join(row[1:]) cur.close() conn.close() Here "recent_tracks" tuple have the values for example: artist 0 - playback_date : 5 May 2010, 11:14 - timestamp : 1273058099 - track : Brian Eno - Web I want to store these value under u_recent_track(Tid,Playback_date,Time_stamp,Track).Can anybody have idea how to sort out this problem? when I tried to run, it shows error: Traceback (most recent call last): File "F:\JavaWorkspace\Test\src\recent_track_database.py", line 50, in <module> VALUES (%s,%s,%s)""", (key, artist[key])) IndexError: tuple index out of range Thanks in advanced!

  Read the article

• Virtual drivers with Windows Driver Model - where to begin?

  - by waitinforatrain

  I've never written drivers before but I'm starting an open-source project that involves creating virtual MIDI ports that will send the MIDI data over a network. For this, I presume I would be creating some sort of virtual driver using WDM (unless it's possible with kernel hooks?) - but being a beginner to driver development I don't know where to begin. Does anyone know any useful resources that would help me with this project? Or some open-source code from a similar project that I could fork as a starting point?

  Read the article

• Why Switch/Case and not If/Else If?

  - by OB OB

  This question in mainly pointed at C/C++, but I guess other languages are relevant as well. I can't understand why is switch/case still being used instead of if/else if. It seems to me much like using goto's, and results in the same sort of messy code, while the same results could be acheived with if/else if's in a much more organized manner. Still, I see these blocks around quite often. A common place to find them is near a message-loop (WndProc...), whereas these are among the places when they raise the heaviest havoc: variables are shared along the entire block, even when not propriate (and can't be initialized inside it). Extra attention has to be put on not dropping break's, and so on... Personally, I avoid using them, and I wonder wether I'm missing something? Are they more efficient than if/else's? Are they carried on by tradition?

  Read the article

• Signal amplitude against time in Java

  - by wsr74ws84

  I'm racking my brain in order to solve a knotty problem (at least for me). While playing an audio file (using Java) I want the signal amplitude to be displayed against time. I mean I'd like to implement a small panel showing a sort of oscilloscope (spectrum analyzer). The audio signal should be viewed in the time domain (vertical axis is amplitude and the horizontal axis is time). Does anyone know how to do it? Is there a good tutorial I can rely on? Since I know very little about Java, I hope someone can help me.

  Read the article

• Forumotion profile customization using jQuery based on URL

  - by Harvengure

  The idea is have a jQuery snippet (I like Jquery...I can understand it better then regular javascript) that will detect that when it has been run on a profile with a url such as "http://customize.forum-motion.com/profile.forum?mode=viewprofile&u=1" (just as an example)...then upon detecting that it is a url of a profile...fetch data from a specific (and most likely hidden) element before wrapping that data in css tags and appending it to the heady of the current document. In short I'm trying to figure out how to make a sort of profile customization system where users can create their own css. The biggest problem I am having so far is figuring out how to make it so that the snippet can figure out what URL its being run on. Is there a function that can do this in jQuery at all?

  Read the article

• scroll bar important query???

  - by rajesh

  Hello all, actually i downloaded code for scroll from....... http://sorgalla.com/jcarousel/ but when i added it in my page and add using code ... function addElement(url,imagePath){ alert(url); alert(imagePath); var container = document.getElementById('sncs'); items = container.getElementsByTagName("li"); //alert(items.length); var new_element = document.createElement('li'); new_element.innerHTML =""; //var raj='1'+new_element.innerHTML; //alert() new_element.className="jcarousel-item jcarousel-item-horizontal jcarousel-item-4 jcarousel-item-4-horizontal"; //container.insertBefore(new_element, container.firstChild); container.appendChild( new_element ); } it added li not at the end but below scroll what will be the problem..... Please help me to sort out this problem....

  Read the article

• Formatting code snippets for blogging on Blogger

  - by nzpcmad

  My blog is hosted on Blogger and I frequently post code snippets in C / C# / Java / XML etc. but I find the snippet gets "mangled". Are there any web sites that I could use to parse the snippet beforehand and sort out the formatting, convert XML "<" to "<" etc. There are a numbers of questions around this area on SO but I couldn't find any that address this question directly. Edit: For @Rich answer, site states "To display the formatted code on your site, you need to get this CSS stylesheet, and add a reference to it in the section of your page". That's the problem - you can't do this on Blogger AFAIK.

  Read the article

• Efficient data structure design

  - by Sway

  Hi there, I need to match a series of user inputed words against a large dictionary of words (to ensure the entered value exists). So if the user entered: "orange" it should match an entry "orange' in the dictionary. Now the catch is that the user can also enter a wildcard or series of wildcard characters like say "or__ge" which would also match "orange" The key requirements are: * this should be as fast as possible. * use the smallest amount of memory to achieve it. If the size of the word list was small I could use a string containing all the words and use regular expressions. however given that the word list could contain potentially hundreds of thousands of enteries I'm assuming this wouldn't work. So is some sort of 'tree' be the way to go for this...? Any thoughts or suggestions on this would be totally appreciated! Thanks in advance, Matt

  Read the article

• Adding Class instance as a new Row in DataGridView (c#)

  - by Amit Shah

  Hi All, I have a class say [Serializable] public class Answer { [DisplayName("ID")] public string ID { get; set; } [DisplayName("Value")] public string Value { get; set; } } and I have a datagridview with bounded columns to the above class. instances of this class Answer are created dynamically as and when required. How do I update datagridview when each and every instance of class is created. is it possible to do something of this sort. dataGridView.Rows.Add(classInstance); Thanks in Advance, Amit

  Read the article

• cached schwartzian transform

  - by davidk01

  I'm going through "Intermediate Perl" and it's pretty cool. I just finished the section on "The Schwartzian Transform" and after it sunk in I started to wonder why the transform doesn't use a cache. In lists that have several repeated values the transform recomputes the value for each one so I thought why not use a hash to cache results. Here' some code: # a place to keep our results my %cache; # the transformation we are interested in sub foo { # expensive operations } # some data my @unsorted_list = ....; # sorting with the help of the cache my @sorted_list = sort { ($cache{$a} or $cache{$a} = &foo($a)) <=> ($cache{$b} or $cache{$b} = &foo($b)) } @unsorted_list; Am I missing something? Why isn't the cached version of the Schwartzian transform listed in books and in general just better circulated because on first glance I think the cached version should be more efficient?

  Read the article

< Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >