Search Results

Search found 9017 results on 361 pages for 'efficient storage'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 186/361 | < Previous Page | 182 183 184 185 186 187 188 189 190 191 192 193  | Next Page >

  • Complex Calculations

    - by mson
    What are the best tools (most efficient) available in .NET (C#) for calculating: integrals partial derivatives other non-trivial math Can people please comment on Mathematica and Matlab and their integration into C#?

    Read the article

  • MvvmCross experiences, hindsight, limitations?

    - by Jason Steele
    I am considering using the MvvmCross framework for a cross platform mobile application that will target Android, iPhone and WP7. Does anyone have any experience with this framework they would like to share, and are they aware of any constraints or limitations that it would be useful to be aware of? For example, am I still able to use native page transitions of my choosing? Are there any performance or storage (app size) implications?

    Read the article

  • Why is the Objective-C Boolean data type defined as a signed char?

    - by EddieCatflap
    Something that has piqued my interest is Objective-C's BOOL type definition. Why is it defined as a signed char (which could cause unexpected behaviour if a value greater than 1 byte in length is assigned to it) rather than as an int, as C does (much less margin for error: a zero value is false, a non-zero value is true)? The only reason I can think of is the Objective-C designers micro-optimising storage because the char will use less memory than the int. Please can someone enlighten me?

    Read the article

  • Are there any platforms where using structure copy on an fd_set (for select() or pselect()) causes p

    - by Jonathan Leffler
    The select() and pselect() system calls modify their arguments (the 'struct fd_set *' arguments), so the input value tells the system which file descriptors to check and the return values tell the programmer which file descriptors are currently usable. If you are going to call them repeatedly for the same set of file descriptors, you need to ensure that you have a fresh copy of the descriptors for each call. The obvious way to do that is to use a structure copy: struct fd_set ref_set_rd; struct fd_set ref_set_wr; struct fd_set ref_set_er; ... ...code to set the reference fd_set_xx values... ... while (!done) { struct fd_set act_set_rd = ref_set_rd; struct fd_set act_set_wr = ref_set_wr; struct fd_set act_set_er = ref_set_er; int bits_set = select(max_fd, &act_set_rd, &act_set_wr, &act_set_er, &timeout); if (bits_set > 0) { ...process the output values of act_set_xx... } } My question: Are there any platforms where it is not safe to do a structure copy of the struct fd_set values as shown? I'm concerned lest there be hidden memory allocation or anything unexpected like that. (There are macros/functions FD_SET(), FD_CLR(), FD_ZERO() and FD_ISSET() to mask the internals from the application.) I can see that MacOS X (Darwin) is safe; other BSD-based systems are likely to be safe, therefore. You can help by documenting other systems that you know are safe in your answers. (I do have minor concerns about how well the struct fd_set would work with more than 8192 open file descriptors - the default maximum number of open files is only 256, but the maximum number is 'unlimited'. Also, since the structures are 1 KB, the copying code is not dreadfully efficient, but then running through a list of file descriptors to recreate the input mask on each cycle is not necessarily efficient either. Maybe you can't do select() when you have that many file descriptors open, though that is when you are most likely to need the functionality.) There's a related SO question - asking about 'poll() vs select()' which addresses a different set of issues from this question.

    Read the article

  • Can I optimize this at all?

    - by Moshe
    I'm working on an iOS app and I'm using the following code for one of my tables to return the number of rows in a particular section: return [[kSettings arrayForKey:@"views"] count]; Is there any other way to write that line of code so that it is more memory efficient? EDIT: kSettings = NSUserDefaults standardUserDefaults. Is there any way to rewrite my line of code so that whatever memory it occupies is released sooner than it is released now?

    Read the article

  • as3 air for android download folder and contents

    - by Papa De Beau
    Is it possible to download a folder and its contents using air for android? I would like to also use the same code on iPhone. I need it to be stored in the application storage so we can reference the content once downloaded. I know it's possible to download content as referenced in this question: Download Content using Air For Android but can a person download the entire folder and again store it in the application directory? Thanks @lukevain? :)

    Read the article

  • circles and triangles problem

    - by Faken
    Hello everyone, I have an interesting problem here I've been trying to solve for the last little while: I have 3 circles on a 2D xy plane, each with the same known radius. I know the coordinates of each of the three centers (they are arbitrary and can be anywhere). What is the largest triangle that can be drawn such that each vertice of the triangle sits on a separate circle, what are the coordinates of those verticies? I've been looking at this problem for hours and asked a bunch of people but so far only one person has been able to suggest a plausible solution (though i have no way of proving it). The solution that we have come up with involves first creating a triangle about the three circle centers. Next we look at each circle individually and calculate the equation of a line that passes through the circle's center and is perpendicular to the opposite edge. We then calculate two intersection points of the circle. This is then done for the next two circles with a result of 6 points. We iterate over the 8 possible 3 point triangles that these 6 points create (the restriction is that each point of the big triangle must be on a separate circle) and find the maximum size. The results look reasonable (at least when drawn out on paper) and it passes the special case of when the centers of the circles all fall on a straight line (gives a known largest triangle). Unfortunate i have no way of proving this is correct or not. I'm wondering if anyone has encountered a problem similar to this and if so, how did you solve it? Note: I understand that this is mostly a math question and not programming, however it is going to be implemented in code and it must be optimized to run very fast and efficient. In fact, I already have the above solution in code and tested to be working, if you would like to take a look, please let me know, i chose not to post it because its all in vector form and pretty much impossible to figure out exactly what is going on (because it's been condensed to be more efficient). Lastly, yes this is for school work, though it is NOT a homework question/assignment/project. It's part of my graduate thesis (abet a very very small part, but still technically is part of it). Thanks for your help.

    Read the article

  • Read part of a file in PHP

    - by Johan
    I would like to read the last 1 megabyte of a MP3 file and calculate SHA1 checksum for just that part of the file. The reason that I would want this is that when I'm looking for duplicate MP3's, the header info (song title, album etc.) can differ even though it's the exakt same audio file, so I figured I would be better of to checksum a part of the file at the end instead of the whole one. Is there an efficient way of doing this?

    Read the article

  • Web site backup in PHP?

    - by Pekka
    Does anybody know a clean PHP-based solution that can backup remote web sites using FTP? Must haves: Recursive FTP backups Possible to run through a cron job Easy to configure (easy adding of multiple sites) Local storage of backup files is sufficient Would be nice: Backed up sites are stored as zip files A nice interface to manage things Provides notification when backup has succeeded or failed Does incremental backups Does MySQL Database backups I need this to be PHP (or Perl) based because it's going to be used on shared hosting packages that do not allow usage of the standard GNU/Linux tools available.

    Read the article

  • C# - Converting a float to an int... and changing the int depending on the remainder

    - by Django Reinhardt
    Hi, this is probably the really newbie question (well, I'm pretty sure it is), but I have a float that's being returned and I need a quick and efficient way of turning it into an int. Pretty simple, but I have an exception. If the remainder of the float is anything other than .0 then I want to increment the int. Some quick examples: Float = 98.0, Int = 98 Float = 98.1, Int = 99 Float = 6.6, Int = 7 etc. Thanks for any help!

    Read the article

  • nested function

    - by user359179
    Hi to all of you, 1.I just came across that ANSI(ISO) aint allow nesting of function.. i want to know what makes gnu c ito implemet this functionality(why such need arise). 2.If a function say(a()) is define with in another function say(b()) then the lifetime of a() would be whole prorgramme? 3.Will the storage for a() ll be created in a stack allocated to function b().?

    Read the article

  • How to optimize foreach loop in PHP

    - by vanneto
    First off, I know the title is generic and not fitting. I just couldn't think of a title that could describe my problem. I have a table Recipients in MySQL structured like this: id | email | status 1 foo@bar S 2 bar@baz S 3 abc@def R 4 sta@cko B I need to convert the data into the following XML, depending on the status field. For example: <Recipients> <RecipientsSent> <!-- Have the 'S' status --> <recipient>foo@bar</recipient> <recipient>bar@baz</recipient> </RecipientsSent> <RecipientsRegexError> <recipient>abc@def</recipient> </RecipientsRegexError> <RecipientsBlocked> <recipient>sta@cko</recipient> </RecipientsBlocked> </Recipients> I have this PHP code to implement this ($recipients contains an associative array of the db table): <Recipients> <RecipientsSent> <?php foreach ($recipients as $recipient): if ($recipient['status'] == 'S'): echo "<recipient>" . $recipient['email'] . "</recipient>"; endif; endforeach; ?> </RecipientsSent> <RecipientsRegexError> <?php foreach ($recipients as $recipient): if ($recipient['status'] == 'R'): echo "<recipient>" . $recipient['email'] . "</recipient>"; endif; endforeach; ?> </RecipientsRegexError> <?php /** same loop for the B status */ ?> </Recipients> So, this means that if I have 1000 entries in the table and 4 different status' that can be checked, it means that there will be 4 loops, each one executing 1000 times. How can this be done in a more efficient manner? I thought about fetching four different sets from the database, meaning 4 different queries, would that be more efficient? I'm thinking it could be done with one loop but but I can't come up with a solution. Any way this could be done with only one loop?

    Read the article

  • How to move value from the stack to ST(0)?

    - by George Edison
    I am having trouble believing the following code is the most efficient way to move a value from the stack to ST(0): .data var dd 4.2 tmp dd ? .code mov EAX, var push EAX ; top of stack now contains a value ; move it to ST(0) pop EAX mov tmp, EAX fld tmp Is the temporary variable really necessary? Further, is there an easier way to get a value from the stack to ST(0)?

    Read the article

  • Architectural Design for a Data-Driven Silverlight WP7 app

    - by Rosarch
    I have a Silverlight Windows Phone 7 app that pulls data from a public API. I find myself doing much of the same thing over and over again: In the UI, set a loading message or loading progress bar in place of where the content is Get the content, which may be already in memory, cached in isolated file storage, or require an HTTP request If the content can not be acquired (no network connection, etc), display an error message If the content is acquired, display it in the UI Keep the content in main memory for subsequent queries The content that is displayed to the user can be taken directly from a data source, such as an ObservableCollection, or it may be a query on a data source. I would like to factor out this repetitive process into a framework where ideally only the following needs to be specified: Where to display the content in the UI The UI elements to show while loading, on failure, and on success The URI of the HTTP request How to parse the HTTP response into the data structure that will kept in memory The location of the file in isolated storage, if it exists How to parse the file contents into the data structure that will be kept in memory It may sound like a lot, but two strings, three FrameworkElements, and two methods is less than the overhead that I currently have. Also, this needs to work for however the data is maintained in memory, and needs to work for direct collections and queries on those collections. My questions are: Has something like this already been implemented? Are my thoughts about the topic above fundamentally wrong in some way? Here is a design I'm thinking of: There are two components, a View and a Model. The View is given the FrameworkElements for loading, failure, and success. It is also given a reference to the corresponding Model. The View is a UserControl that is placed somewhere in the UI. The Model a class that is given the URI for the data, a method of how to parse the data, and optionally a filename and how to parse the file. It is responsible for retrieving the data and notifying the View whenever the current status (loading/fail/success) changes. If the data downloaded from the network is different from the cache, the network data takes precedence. When the app closes or is tombstoned, the model writes the data to the cache. How does that sound?

    Read the article

  • Databases: Migrate data between MS Access DB and MYSQL

    - by Dean
    Hello, I have 2 databases, one is MS Access DB from an old website, and the other one is MYSQL from the new Joomla+VirtueMart based website. I need to migrate existing products from MS Access to MYSQL. I thought of putting both on server and writing SQL queries in MYSQL workbench, untill I have a good script for that, but I'm very new to SQL, so I'd rather avoid that. I there a better way and more efficient for that?

    Read the article

  • slicing arrays in numpy/scipy

    - by user248237
    I have an array like: a = array([[1,2,3],[3,4,5],[4,5,6]]) what's the most efficient way to slice out a 1x2 array out of this that has only the first two columns of "a"? I.e., array([[2,3],[4,5],[5,6]]) in this case. thanks.

    Read the article

  • Doing a count over a filter query efficiently in django

    - by apple_pie
    Hello, Django newbie here, I need to do a count over a certain filter in a django model. If I do it like so: my_model.objects.filter(...).count() I'm guessing it does the SQL query that retrieves all the rows and only afterwards does the count. To my knowledge it's much more efficient to do the count without retrieving those rows like so "SELECT COUNT(*) FROM ...". Is there a way to do so in django?

    Read the article

  • Performance - FunctionCall vs Event vs Action vs Delegate

    - by hwcverwe
    Currently I am using Microsoft Sync Framework to synchronize databases. I need to gather information per record which is inserted/updated/deleted by Microsoft Sync Framework and do something with this information. The sync speed can go over 50.000 records per minute. So that means my additional code need to be very lightweight otherwise it will be a huge performance penalty. Microsoft Sync Framework raises an SyncProgress event for each record. I am subscribed to that code like this: // Assembly1 SyncProvider.SyncProgress += OnSyncProgress; // .... private void OnSyncProgress(object sender, DbSyncProgressEventArgs e) { switch (args.Stage) { case DbSyncStage.ApplyingInserts: // MethodCall/Delegate/Action<>/EventHandler<> => HandleInsertedRecordInformation // Do something with inserted record info break; case DbSyncStage.ApplyingUpdates: // MethodCall/Delegate/Action<>/EventHandler<> => HandleUpdatedRecordInformation // Do something with updated record info break; case DbSyncStage.ApplyingDeletes: // MethodCall/Delegate/Action<>/EventHandler<> => HandleDeletedRecordInformation // Do something with deleted record info break; } } Somewhere else in another assembly I have three methods: // Assembly2 public class SyncInformation { public void HandleInsertedRecordInformation(...) {...} public void HandleUpdatedRecordInformation(...) {...} public void HandleInsertedRecordInformation(...) {...} } Assembly2 has a reference to Assembly1. So Assembly1 does not know anything about the existence of the SyncInformation class which need to handle the gathered information. So I have the following options to trigger this code: use events and subscribe on it in Assembly2 1.1. EventHandler< 1.2. Action< 1.3. Delegates using dependency injection: public class Assembly2.SyncInformation : Assembly1.ISyncInformation Other? I know the performance depends on: OnSyncProgress switch using a method call, delegate, Action< or EventHandler< Implementation of SyncInformation class I currently don't care about the implementation of the SyncInformation class. I am mainly focused on the OnSyncProgress method and how to call the SyncInformation methods. So my questions are: What is the most efficient approach? What is the most in-efficient approach? Is there a better way than using a switch in OnSyncProgress?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 182 183 184 185 186 187 188 189 190 191 192 193  | Next Page >