Search Results

Search found 17686 results on 708 pages for 'high level'.

Page 584/708 | < Previous Page | 580 581 582 583 584 585 586 587 588 589 590 591  | Next Page >

• WM_NOTIFY and superclass chaining issue in Win32

  - by DasMonkeyman

  For reference I'm using the window superclass method outlined in this article. The specific issue occurs if I want to handle WM_NOTIFY messages (i.e. for custom drawing) from the base control in the superclass I either need to reflect them back from the parent window or set my own window as the parent (passed inside CREATESTRUCT for WM_(NC)CREATE to the base class). This method works fine if I have a single superclass. If I superclass my superclass then I run into a problem. Now 3 WindowProcs are operating in the same HWND, and when I reflect WM_NOTIFY messages (or have them sent to myself from the parent trick above) they always go to the outermost (most derived) WindowProc. I have no way to tell if they're messages intended for the inner superclass (base messages are supposed to go to the first superclass) or messages intended for the outer superclass (messages from the inner superclass are intended for the outer superclass). These messages are indistinguishable because they all come from the same HWND with the same control ID. Is there any way to resolve this without creating a new window to encapsulate each level of inheritance? Sorry about the wall of text. It's a difficult concept to explain. Here's a diagram. single superclass: SuperA::WindowProc() - Base::WindowProc()---\ ^--------WM_NOTIFY(Base)--------/ superclass of a superclass: SuperB::WindowProc() - SuperA::WindowProc() - Base::WindowProc()---\ ^--------WM_NOTIFY(Base)--------+-----------------------/ ^--------WM_NOTIFY(A)-----------/ The WM_NOTIFY messages in the second case all come from the same HWND and control ID, so I cannot distinguish between the messages intended for SuperA (from Base) and messages intended for SuperB (from SuperA). Any ideas?

  Read the article

• How do you get the viewport scale after pinch/zoom on an iPhone web app?

  - by Loktar

  Does anyone know how to get the size in pixels or scale value of the viewport after a user has pinched or double tapped to zoom in/out on a page in JavaScript? I've tried using window.innerWidth but I've had mixed results. Sometimes it seems to accurately give the number of pixels the viewport is showing, however, if I zoom way in on a page and then do a large pinch to zoom back out, window.innerWidth will be around 600-700 even though it is only showing ~200px of the page. The page is only 400px wide and it didn't show the checkered "you've gone too far" background you see when you zoom out beyond the page size. If I do small pinches to zoom in and out, window.innerWidth appears to work just fine. Unfortunately I can't rely on a user only making small pinch gestures :) I've also tried to use the scale property on the gesture event object, but I've found that unreliable because you don't always know the initial scale when you reload the page or use back/forward buttons to navigate to it even when using the meta tag to specify it. Ultimately, I'm trying to make an app that is aware of when a user is trying to zoom out beyond the maximum zoom level so if there is another way to do this I'm interested in hearing about it :) Here's the code I'm using to get the innerWidth: document.body.addEventListener('gestureend', function (evt) { console.log(window.innerWidth); // inaccurate when doing large pinch gestures }, false); Thanks!

  Read the article

• Vertex Buffers in opengl

  - by JB

  I'm making a small 3d graphics game/demo for personal learning. I know d3d9 and quite a bit about d3d11 but little about opengl at the moment so I'm intending to abstract out the actual rendering of the graphics so that my scene graph and everything "above" it needs to know little about how to actually draw the graphics. I intend to make it work with d3d9 then add d3d11 support and finally opengl support. Just as a learning exercise to learn about 3d graphics and abstraction. I don't know much about opengl at this point though, and don't want my abstract interface to expose anything that isn't simple to implement in opengl. Specifically I'm looking at vertex buffers. In d3d they are essentially an array of structures, but looking at the opengl interface the equivalent seems to be vertex arrays. However these seem to be organised rather differently where you need a separate array for vertices, one for normals, one for texture coordinates etc and set the with glVertexPointer, glTexCoordPointer etc. I was hoping to be able to implement a VertexBuffer interface much like the the directx one but it looks like in d3d you have an array of structures and in opengl you need a separate array for each element which makes finding a common abstraction quite hard to make efficient. Is there any way to use opengl in a similar way to directx? Or any suggestions on how to come up with a higher level abstraction that will work efficiently with both systems?

  Read the article

• Convert a raw string to an array of big-endian words with Ruby

  - by Zag zag..

  Hello, I would like to convert a raw string to an array of big-endian words. As example, here is a JavaScript function that do it well (by Paul Johnston): /* * Convert a raw string to an array of big-endian words * Characters >255 have their high-byte silently ignored. */ function rstr2binb(input) { var output = Array(input.length >> 2); for(var i = 0; i < output.length; i++) output[i] = 0; for(var i = 0; i < input.length * 8; i += 8) output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (24 - i % 32); return output; } I believe the Ruby equivalent can be String#unpack(format). However, I don't know what should be the correct format parameter. Thank you for any help. Regards

  Read the article

• Delphi: Error when starting MCI

  - by marco92w

  I use the TMediaPlayer component for playing music. It works fine with most of my tracks. But it doesn't work with some tracks. When I want to play them, the following error message is shown: Which is German but roughly means that: In the project pMusicPlayer.exe an exception of the class EMCIDeviceError occurred. Message: "Error when starting MCI.". Process was stopped. Continue with "Single Command/Statement" or "Start". The program quits directly after calling the procedure "Play" of TMediaPlayer. This error occurred with the following file for example: file size: 7.40 MB duration: 4:02 minutes bitrate: 256 kBit/s I've encoded this file with a bitrate of 128 kBit/s and thus a file size of 3.70 MB: It works fine! What's wrong with the first file? Windows Media Player or other programs can play it without any problems. Is it possible that Delphi's TMediaPlayer cannot handle big files (e.g. 5 MB) or files with a high bitrate (e.g. 128 kBit/s)? What can I do to solve the problem?

  Read the article

• Any info about book "Unix Internals: The New Frontiers" by Uresh Vahalia 2nd edition (Jan 2010)

  - by claws

  This summer I'm getting into UNIX (mostly *BSD) development. I've graduate level knowledge about operating systems. I can also understand the code & read from here and there but the thing is I want to make most of my time. Reading books are best for this. From my search I found that these two books The Design and Implementation of the 4.4 BSD Operating System "Unix Internals: The New Frontiers" by Uresh Vahalia are like established books on UNIX OS internals. But the thing is these books are pretty much outdated. yay!! Lucky me. "Unix Internals: The New Frontiers" by Uresh Vahalia 2 edition (Jan 2010) is released. I've been search for information on this book. Sadly, Amazon says "Out of Print--Limited Availability" & I couldn't find any info regarding this book. This is the information I'm looking for: Table of Contents Whats new in this edition? Where the hell can I buy soft-copy of this book? I really cannot afford buying a hardcopy. How can I contact the author? I've lot of hopes & expectations on this book. I've been waiting for its release for a long time. I've sent random mails to & & requesting to have a proper website for this book. I even contacted publisher for any further information but no replies from any one. If you have any other books that you think will help me. I again repeat, I want to get max possible out of these 2.5 months summer.

  Read the article

• Mac OS X Status Bar Application - Hiding it from Cmd/Alt menu?

  - by Moddy

  I'm trying to whip up a simple little Status Bar Application in Obj-C/Cocoa. So I have done it pragmatically - declaring an NSStatusItem, adding it to the NSStatusBar and then giving it a NSMenu object. A bit like this... NSStatusBar *bar = [NSStatusBar systemStatusBar]; theItem = [bar statusItemWithLength:NSVariableStatusItemLength]; [theItem retain]; [theItem setTitle: NSLocalizedString(@"Tablet",@"")]; [theItem setHighlightMode:YES]; [theItem setMenu:theMenu]; (Example taken from "Status Bar Programming Topics", Apple Documentation) Now ideally, I'd like this application to run and not be accessible from the CMD/ALT window changing "menu" (for lack of a better word), I've seen applications do it before and would like that really. The idea is I just want it to be accessible from every window, whilst not having its own NSMenu on the status bar, and whilst not being able to have it as the active application ( - so its not able to take over the whole Status Bar, and its not able to be seen through CMD/ALT) Additionally, I was wondering if the StatusBarItem supports the ability to drag-n-drop an item onto it? I'm not sure if thats a limitation of the NSStatusBar though. I've read up on deamons and agents, but that seems far too low level/over kill for such a simplistic app! Cheers in advance!

  Read the article

• ExpertPDF and Caching of URLs

  - by Josh

  We are using ExpertPDF to take URLs and turn them into PDFs. Everything we do is through memory, so we build up the request and then read the stream into ExpertPDF and then write the bits to file. All the files we have been requesting so far are just plain HTML documents. Our designers update CSS files or change the HTML and rerequest the documents as PDFs, but often times, things are getting cached. Take, for example, if I rename the only CSS file and view the HTML page through a web browser, the page looks broke because the CSS doesn't exist. But if I request that page through the PDF Generator, it still looks ok, which means somewhere the CSS is cached. Here's the relevant PDF creation code: // Create a request HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url); request.UserAgent = "IE 8.0"; request.ContentType = "application/x-www-form-urlencoded"; request.Method = "GET"; // Send the request HttpWebResponse resp = (HttpWebResponse)request.GetResponse(); if (resp.IsFromCache) { System.Web.HttpContext.Current.Trace.Write("FROM THE CACHE!!!"); } else { System.Web.HttpContext.Current.Trace.Write("not from cache"); } // Read the response pdf.SavePdfFromHtmlStream(resp.GetResponseStream(), System.Text.Encoding.UTF8, "Output.pdf"); When I check the trace file, nothing is being loaded from cache. I checked the IIS log file and found a 200 response coming from the request, even after a file had been updated (I would expect a 302). We've tried putting the No-Cache attribute on all HTML pages, but still no luck. I even turned off all caching at the IIS level. Is there anything in ExpertPDF that might be caching somewhere or something I can do to the request object to do a hard refresh of all resources? UPDATE I put ?foo at the end of my style href links and this updates the CSS everytime. Is there a setting someplace that can prevent stylesheets from being cached so I don't have to do this inelegant solution?

  Read the article

• DSP - Filter sweep effect

  - by Trap

  I'm implementing a 'filter sweep' effect (I don't know if it's called like that). What I do is basically create a low-pass filter and make it 'move' along a certain frequency range. To calculate the filter cut-off frequency at a given moment I use a user-provided linear function, which yields values between 0 and 1. My first attempt was to directly map the values returned by the linear function to the range of frequencies, as in cf = freqRange * lf(x). Although it worked ok it looked as if the sweep ran much faster when moving through low frequencies and then slowed down during its way to the high frequency zone. I'm not sure why is this but I guess it's something to do with human hearing perceiving changes in frequency in a non-linear manner. My next attempt was to move the filter's cut-off frequency in a logarithmic way. It works much better now but I still feel that the filter doesn't move at a constant perceived speed through the range of frequencies. How should I divide the frequency space to obtain a constant perceived sweep speed? Thanks in advance.

  Read the article

• How to retrieve view of MultiIndex DataFrame

  - by Henry S. Harrison

  This question was inspired by this question. I had the same problem, updating a MultiIndex DataFrame by selection. The drop_level=False solution in Pandas 0.13 will allow me to achieve the same result, but I am still wondering why I cannot get a view from the MultiIndex DataFrame. In other words, why does this not work?: >>> sat = d.xs('sat', level='day', copy=False) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 2248, in xs raise ValueError('Cannot retrieve view (copy=False)') ValueError: Cannot retrieve view (copy=False) Of course it could be only because it is not implemented, but is there a reason? Is it somehow ambiguous or impossible to implement? Returning a view is more intuitive to me than returning a copy then later updating the original. I looked through the source and it seems this situation is checked explicitly to raise an error. Alternatively, is it possible to get the same sort of view from any of the other indexing methods? I've experimented but have not been successful. [edit] Some potential implementations are discussed here. I guess with the last question above I'm wondering what the current best solution is to index into arbitrary multiindex slices and cross-sections.

  Read the article

• The uncatchable exception, pt 2

  - by chaiguy

  Ok I've done some testing and I've reduced the problem to something very simple: i. Create a method in a new class that throws an exception: public class Class1 { public void CallMe() { string blah = null; blah.ToLower(); } } ii. Create a MethodInfo that points to this method somewhere else: Type class1 = typeof( Class1 ); Class1 obj = new Class1(); MethodInfo method = class1.GetMethod( "CallMe" ); iii. Wrap a call to Invoke() in a try/catch block: try { method.Invoke( obj, null ); // exception is not being caught! } catch { } iv. Run the program without the debugger (works fine). v. Now run the program with the debugger. The debugger will halt the program when the exception occurs, even though it's wrapped in a catch handler that tries to ignore it. (Even if you put a breakpoint in the catch block it will halt before it reaches it!) In fact, the exception is happening when you run it without the debugger too. In a simple test project it's getting ignored at some other level, but if your app has any kind of global exception handling, it will get triggered there as well. This is causing me a real headache because it keeps triggering my app's crash-handler, not to mention the pain it is to attempt to debug.

  Read the article

• Internet zone is opened when broswer is opened from installer created by .Net 3.5sp1

  - by priya

  Hi All, I have project created in VS2005 and .Net 2.0. The installation is a web-based installation. After installing the proe-requisites the installer opens up the browser to continue with web-based install. On this, it opens up in intranet zone and works perfectly. I recently migrated the project to VS2008 Sp1 and .Net 3.5sp1. No change in my code and the test environment. Here the browser gets opened up in the Internet zone which prevents it from moving forward, until unless I open up a new browser manually and copy paste the url. The internet security options on the both the case are - Internet --- High. For the case2, if i have the security internet option to be 'Medium', it works well. I am not sure why this issue comes up when I change the VS and .Net version. More over the browser gets opened with system priveleges rather than administrator privileges. Please let me know any solution on this. Thanks, Priya.R

  Read the article

• Ogre material scripts; how do I give a technique multiple lod_indexes?

  - by BlueNovember

  I have an Ogre material script that defines 4 rendering techniques. 1 using GLSL shaders, then 3 others that just use textures of different resolutions. I want to use the GLSL shader unconditionally if the graphics card supports it, and the other 3 textures depending on camera distance. At the moment my script is; material foo { lod_distances 1600 2000 technique shaders { lod_index 0 lod_index 1 lod_index 2 //various passes here } technique high_res { lod_index 0 //various passes here } technique medium_res { lod_index 1 //various passes here } technique low_res { lod_index 2 //various passes here } Extra information The Ogre manual says; Increasing indexes denote lower levels of detail You can (and often will) assign more than one technique to the same LOD index, what this means is that OGRE will pick the best technique of the ones listed at the same LOD index. OGRE determines which one is 'best' by which one is listed first. Currently, on a machine supporting the GLSL version I am using, the script behaves as follows; Camera 2000 : Shader technique Camera 1600 <= 2000 : Medium Camera <= 1600 : High If I change the lod order in shader technique to { lod_index 2 lod_index 1 lod_index 0 } The behaviour becomes; Camera 2000 : Low Camera 1600 <= 2000 : Medium Camera <= 1600 : Shader implying only the latest lod_index is used. If I change it to lod_index 0 1 2 It shouts at me Compiler error: fewer parameters expected in foo.material(#): lod_index only supports 1 argument So how do I specify a technique to have 3 lod_indexes? Duplication works; technique shaders { lod_index 0 //various passes here } technique shaders1 { lod_index 1 //passes repeated here } technique shaders2 { lod_index 2 //passes repeated here } ...but it's ugly.

  Read the article

• R : remove columns from dataframe where ALL values are NA

  - by Sophomore

  hello everybody! I'm having some trouble with my huge data frame and couldn't really resolve that question myself: The dataframe has some properties as columns and each row represents one data set. I've done some sanatizing to this dataframe (e.g. get rid of datasets which are not to be included in evaluation). (Whoever might be interested: Beforehand I aggregate around 5000 single text files and put them in a tsv, some of the proerties have a sequence number like "button.pressed.1" ... ""button.pressed.n". Some of the sets excluded had really high numbers for n but got excluded, all sets left have much smaller numbers for n but the property "button.presed.50" is still there and all remaining sets have an NA in that column. Actually its a different property but the example should clarify my intention...) So the question is quite simple (for some sophisticated R pro): I need to get rid of columns where for ALL rows the value is NA. Could someone please help me out? (All I have managed to get rid of columns where at least one NA exists which dropped about half my columns)...

  Read the article

• Flash won't load, embed error?

  - by Adrian M.

  Hello, I want to know why the flash movie in the header located here: http://www.dolphintemplate.com/demo/dolphin7/index.php?skin=dt_firestarter_red only loads in Firefox but NOT in IE and Chrome.. The flash movie resides in a iframe, this is the code of the iframe: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>header</title> </head> <body bgcolor="#000000" topmargin="0" leftmargin="0" marginwidth="0" marginheight="0"> <object data="header.swf" type="application/x-shockwave-flash" id="myflash" width="988" height="240"> <param name="movie" value="header.swf" /> <param name="bgcolor" value="#000000" /> <param name="height" value="988" /> <param name="width" value="240" /> <param name="quality" value="high" /> <param name="menu" value="false" /> <param name="allowscriptaccess" value="samedomain" /> <p>Adobe <a href="http://get.adobe.com/flashplayer/">Flash Player</a> is required to view this content.</p> </object> </body> </html> Thanks.

  Read the article

• How to structure an index for type ahead for extremely large dataset using Lucene or similar?

  - by Pete

  I have a dataset of 200million+ records and am looking to build a dedicated backend to power a type ahead solution. Lucene is of interest given its popularity and license type, but I'm open to other open source suggestions as well. I am looking for advice, tales from the trenches, or even better direct instruction on what I will need as far as amount of hardware and structure of software. Requirements: Must have: The ability to do starts with substring matching (I type in 'st' and it should match 'Stephen') The ability to return results very quickly, I'd say 500ms is an upper bound. Nice to have: The ability to feed relevance information into the indexing process, so that, for example, more popular terms would be returned ahead of others and not just alphabetical, aka Google style. In-word substring matching, so for example ('st' would match 'bestseller') Note: This index will purely be used for type ahead, and does not need to serve standard search queries. I am not worried about getting advice on how to set up the front end or AJAX, as long as the index can be queried as a service or directly via Java code. Up votes for any useful information that allows me to get closer to an enterprise level type ahead solution

  Read the article

• How to set the VirtualDocumentRoot based on the files within

  - by Chuck Vose

  I'm trying to set up Apache to use the VirtualDocumentRoot directive but my sites aren't all exactly the same. Most of the sites have a drupal folder which should be the root but there are a few really old drupal sites, a few rails sites, some django sites, etc. that want the Document root to be / or some other folder. Is there a way to set up VirtualDocumentRoot based on a conditional or is there a way to use RewriteRule/Cond to detect that / is the incorrect folder if there is a drupal folder or a public folder? Here's what I have so far: <VirtualHost *:80> # Wildcard ServerAlias, this is the default vhost if no specific vhost matches first. ServerAlias *.unicorn.devserver.com # Automatic ServerName, based on the HTTP_HOST header. UseCanonicalName Off # Automatic DocumentRoot. This uses the 4th level domain name as the document root, # for example http://bar.foo.baz.com/ would respond with /Users/vosechu/Sites/bar/drupal. VirtualDocumentRoot /Users/vosechu/Sites/%-4/drupal </VirtualHost> Thanks in advance! -Chuck

  Read the article

• Postgres error with Sinatra/Haml/DataMapper on Heroku

  - by sevennineteen

  I'm trying to move a simple Sinatra app over to Heroku. Migration of the Ruby app code and existing MySQL database using Taps went smoothly, but I'm getting the following Postgres error: PostgresError - ERROR: operator does not exist: text = integer LINE 1: ...d_at", "post_id" FROM "comments" WHERE ("post_id" IN (4, 17,... ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts. It's evident that the problem is related to a type mismatch in the query, but this is being issued from a Haml template by the DataMapper ORM at a very high level of abstraction, so I'm not sure how I'd go about controlling this... Specifically, this seems to be throwing up on a call of p.comments from my Haml template, where p represents a given post. The Datamapper models are related as follows: class Post property :id, Serial ... has n, :comments end class Comment property :id, Serial ... belongs_to :post end This works fine on my local and current hosted environment using MySQL, but Postgres is clearly more strict. There must be hundreds of Datamapper & Haml apps running on Postgres DBs, and this model relationship is super-conventional, so hopefully someone has seen (and determined how to fix) this. Thanks!

  Read the article

• Python, Ruby, and C#: Use cases?

  - by thaorius

  Hi everyone. For as long as I can remember, I've always had a "favorite" language, which I use for most projects, until, for some particular reason, there is no way/point on using it for project XYZ. At that point, I find myself rusty (and sometimes outdated) on other languages+libraries+toolchains. So I decided, I would just use some languages/libs/tools for some things, and some for other, effectively keeping them fresh (there would obviously be exceptions, I'm not looking for an arbitrary rule set, but some guidelines). I wanted an opinion on what would be your standard use cases (new projects) for Python, Ruby, and C# (Mono). At the moment, I have time like this:Languages: C#: Mid-Large Sized Projects (mainly server-side daemons) High Performance (I hardly ever need C's performance, but Python just doesn't cut it) Relatively Low Footprint (vs the JVM, for example) Ruby: Web Applications Python: General Use Scripts (automation, system config, etc) Small-Mid Sized Projects Prototyping Web Applications About Ruby, I have no idea what to use it for that I can't use Python for (specially considering Python is more easily found installed by default). And I like both languages (though I'm really new to Ruby), which makes things even worse. As for C#, I have not used a Windows powered computer in a few years, I don't make things for Windows computers, and I don't mind waiting for Mono to implement some new features. That being said, I haven't found many people on the internet using it for server-sided *nix programming (not web related). I would appreciate some insight on this too. Thanks for your time.

  Read the article

• Colorizing as SAS Map

  - by user601828

  I'm trying to generate a map in SAS where I would like to to make gradual color changes which correspond to my results. So the higher the counts the more intense the color changes. Also I would like to add state labels to the map. Here is my code, so far it produces a white map with varying degress of blue blocks. I'd like the states colored in intense colors, like red, bright pink,brilliant, blues and greens. Can anyone please help me modify the code to add state labels and colorize the map, and below the map add a table summarizing the statistics, like counts and percentages. Thanks in advance. goptions gunit=pct cback=white htitle=4 htext=3 colors=(PAGY LIY STY DEGY dark_yellow very_dark_yellow ) ; title "My Map Results"; proc gmap map=maps.us data=My_data all; id state; block person_per_event/levels=6; choro person_per_event/levels=6; run; quit; I looked at his page before for example if I wanted to make a map like this one http://robslink.com/SAS/democd61/election_2012.htm with my data. I tried modifying the code that he gives on the link, but wasnt very successful. I would like to use that map along with the state labels and keep the colors and represent my data with blocks in the corresponding locations with city and state, and high level counts. The rest of the summary statistics I would like to summarize in a colorful table next to the map, like a dashboard of sorts. Appreciate any help in advance. Thanks, -rachel

  Read the article

• Natural problems to solve using closures

  - by m.u.sheikh

  I have read quite a few articles on closures, and, embarassingly enough, I still don't understand this concept! Articles explain how to create a closure with a few examples, but I don't see any point in paying much attention to them, as they largely look contrived examples. I am not saying all of them are contrived, just that the ones I found looked contrived, and I dint see how even after understanding them, I will be able to use them. So in order to understand closures, I am looking at a few real problems, that can be solved very naturally using closures. For instance, a natural way to explain recursion to a person could be to explain the computation of n!. It is very natural to understand a problem like computing the factorial of a number using recursion. Similarly, it is almost a no-brainer to find an element in an unsorted array by reading each element, and comparing with the number in question. Also, at a different level, doing Object-oriented programming also makes sense. So I am trying to find a number of problems that could be solved with or without closures, but using closures makes thinking about them and solving them easier. Also, there are two types to closures, where each call to a closure can create a copy of the environment variables, or reference the same variables. So what sort of problems can be solved more naturally in which of the closure implementations?

  Read the article

• Pseudo-quicksort time complexity

  - by Ord

  I know that quicksort has O(n log n) average time complexity. A pseudo-quicksort (which is only a quicksort when you look at it from far enough away, with a suitably high level of abstraction) that is often used to demonstrate the conciseness of functional languages is as follows (given in Haskell): quicksort :: Ord a => [a] -> [a] quicksort [] = [] quicksort (p:xs) = quicksort [y | y<-xs, y<p] ++ [p] ++ quicksort [y | y<-xs, y>=p] Okay, so I know this thing has problems. The biggest problem with this is that it does not sort in place, which is normally a big advantage of quicksort. Even if that didn't matter, it would still take longer than a typical quicksort because it has to do two passes of the list when it partitions it, and it does costly append operations to splice it back together afterwards. Further, the choice of the first element as the pivot is not the best choice. But even considering all of that, isn't the average time complexity of this quicksort the same as the standard quicksort? Namely, O(n log n)? Because the appends and the partition still have linear time complexity, even if they are inefficient.

  Read the article

• Set "Start With" value for Oracle sequence dynamically

  - by Allan

  I'm trying to create a release script that can be deployed on multiple databases, but where the data can be merged back together at a later date. The obvious way to handle this is to set the sequence numbers for production data sufficiently high in subsequent deployments to prevent collisions. The problem is in coming up with a release script that will accept the environment number and set the "Start With" value of the sequences appropriately. Ideally, I'd like to use something like this: ACCEPT EnvironNum PROMPT 'Enter the Environment Number: ' --[more scripting] CREATE SEQUENCE seq1 START WITH &EnvironNum*100000; --[more scripting] This doesn't work because you can't evaluate a numeric expression in DDL. Another option is to create the sequences using dynamic SQL via PL/SQL. ACCEPT EnvironNum PROMPT 'Enter the Environment Number: ' --[more scripting] EXEC execute immediate 'CREATE SEQUENCE seq1 START WITH ' || &EnvironNum*100000; --[more scripting] However, I'd prefer to avoid this solution as I generally try to avoid issuing DDL in PL/SQL. Finally, the third option I've come up with is simply to accept the Start With value as a substitution variable, instead of the environment number. Does anyone have a better thought on how to go about this?

  Read the article

• Best method to select an object from another unknown jQuery object

  - by Yosi

  Lets say I have a jQuery object/collection stored in a variable named obj, which should contain a DOM element with an id named target. I don't know in advance if target will be a child in obj, i.e.: obj = $('<div id="parent"><div id="target"></div></div>'); or if obj equals target, i.e.: obj = $('<div id="target"></div>'); or if target is a top-level element inside obj, i.e.: obj = $('<div id="target"/><span id="other"/>'); I need a way to select target from obj, but I don't know in advance when to use .find and when to use .filter. What would be the fastest and/or most concise method of extracting target from obj? What I've come up with is: var $target = obj.find("#target").add(obj.filter("#target")); UPDATE I'm adding solutions to a JSPERF test page to see which one is the best. Currently my solution is still the fastest. Here is the link, please run the tests so that we'll have more data: http://jsperf.com/jquery-selecting-objects

  Read the article

• How to eliminate tearing from animation?

  - by MusiGenesis

  I'm running an animation in a WinForms app at 18.66666... frames per second (it's synced with music at 140 BPM, which is why the frame rate is weird). Each cel of the animation is pre-calculated, and the animation is driven by a high-resolution multimedia timer. The animation itself is smooth, but I am seeing a significant amount of "tearing", or artifacts that result from cels being caught partway through a screen refresh. When I take the set of cels rendered by my program and write them out to an AVI file, and then play the AVI file in Windows Media Player, I do not see any tearing at all. I assume that WMP plays the file smoothly because it uses DirectX (or something else) and is able to synchronize the rendering with the screen's refresh activity. It's not changing the frame rate, as the animation stays in sync with the audio. Is this why WMP is able to render the animation without tearing, or am I missing something? Is there any way I can use DirectX (or something else) in order to enable my program to be aware of where the current scan line is, and if so, is there any way I can use that information to eliminate tearing without actually using DirectX for displaying the cels? Or do I have to fully use DirectX for rendering in order to deal with this problem? Update: forgot a detail. My app renders each cell onto a PictureBox using Graphics.DrawImage. Is this significantly slower than using BitBlt, such that I might eliminate at least some of the tearing by using BitBlt?

  Read the article

< Previous Page | 580 581 582 583 584 585 586 587 588 589 590 591  | Next Page >