Search Results

Search found 6682 results on 268 pages for 'edge cases'.

Page 14/268 | < Previous Page | 10 11 12 13 14 15 16 17 18 19 20 21  | Next Page >

  • Scanline filling of polygons that share edges and vertices

    - by Belgin
    In this picture (a perspective projection of an icosahedron), the scanline (red) intersects that vertex at the top. In an icosahedron each edge belongs to two triangles. From edge a, only one triangle is visible, the other one is in the back. Same for edge d. Also, in order to determine what color the current pixel should be, each polygon has a flag which can either be 'in' or 'out', depending upon where on the scanline we currently are. Flags are flipped according to the intersection of the scanline with the edges. Now, as we go from a to d (because all edges are intersected with the scanline at that vertex), this happens: the triangle behind triangle 1 and triangle 1 itself are set 'in', then 2 is set in and 1 is 'out', then 3 is set 'in', 2 is 'out' and finally 3 is 'out' and the one behind it is set 'in', which is not the desired behavior because we only need the triangles which are facing us to be set 'in', the rest should be 'out'. How do process the edges in the Active Edge List (a list of edges that are currently intersected by the scanline) so the right polys are set 'in'? Also, I should mention that the edges are unique, which means there exists an array of edges in the data structure of the icosahedron which are pointed to by edge pointers in each of the triangles.

    Read the article

  • Algorithm to infer tag hierarchy

    - by Tom
    I'm looking for an algorithm to infer a hierarchy from a set of tagged items. E.g. if the following items have the tags: 1 a 2 a,b 3 a,c 4 a,c,e 5 a,b 6 a,c 7 d 8 d,f Then I can construct an undirected graph (or graphs) by tallying the node weights and edge weights: node weights edge weights a 6 a-b 2 b 2 a-c 3 c 3 c-e 1 d 2 a-e 1 <-- this edge is parallel to a-c and c-e and not wanted e 1 d-f 1 f 1 The first problem is how to drop any redundant edges to get to the simplified graph? Note that it's only appropriate to remove that redundant a-e edge in this case because something is tagged as a-c-e, if that wasn't the case and the tag was a-e, that edge would have to remain. I suspect that means the removal of edges can only happen during the construction of the graph, not after everything has been tallied up. What I'd then like to do is identify the direction of the edges to create a directed graph (or graphs) and pick out root nodes to hopefully create a tree (or trees): trees a d // \\ | b c f \ e It seems like it could be a string algorithm - longest common subsequences/prefixes - or a tree/graph algorithm, but I am a little stuck since I don't know the correct terminology to search for it.

    Read the article

  • How do I fix dragging windows to the adjacent workspace?

    - by Bill O'Dwyer
    I installed CompizConfig-Settings-Manager and I put on all the settings I liked and had in 11.10, including the ability to drag my windows to the adjacent workspace. It's under the Desktop Wall section, on the Edge Flipping tab and I've checked "Edge Flip Move" and "Edge Flip DnD." In 11.10, the movement was smooth between each workspace, and the window would still be "grabbed" in the same place. In 12.04, it's leaving the window behind and the mouse appears to be "grabbing" nothing, but I'm still holding onto the window, and I can still move and place it within the workspace (or indeed the previous workspace as it won't appear in the desired place until I drag the mouse all the way to the edge of the screen). Any way to fix this? I'm running 12.04 beta 2.

    Read the article

  • Adobe Acrobat Reader don't zoom out the page enough in "one page" mode

    - by mbaitoff
    I'm using Adobe Acrobat Reader version 9.4 under Debian Lenny. I'm experiencing a problem: when I push the "Show one page at a time" button, I expect the page to zoom such that pressing PgUp/PgDn would turn to the next/previous page. However, the zoom seems to be not enough - very thin bottom portion of the page doesn't fit inside the reader window, and pressing PgUp/PgDn gives the jitter of the same page, and I have to push twice to get to the next page. It is even worse in continuous page mode - a roll of pages begin to be non-synced with window boundaries, ending up with page break right in the middle of the view after several turns of the pages. This behaviour doesn't occur on windows version - I have a page properly zoomed in single/continuous modes, so that turning the pages is performed as page-at-once, as intended. How to make the Acrobat Reader fit the page to window properly? Thats how it looks before pressing PgDn (notice the bottom edge of the "paper" hidden beneath the bottom window edge): Thats how it looks after pressing PgDn (notice the "paper" bottom edge emerged from beneath the window edge, while the "paper" upper edge hides behind the upper window edge, showing that the document window size is not enough to contain the whole page):

    Read the article

  • Let and construct versus let in sequence

    - by Stringer
    Consider this OCaml code: let coupe_inter i j cases = let lcases = Array.length cases in let low,_,_ = cases.(i) and _,high,_ = cases.(j) in low,high, Array.sub cases i (j-i+1), case_append (Array.sub cases 0 i) (Array.sub cases (j+1) (lcases-(j+1))) Why the expression let ... and ... in is used in place of a let ... in let ... in sequence (like F# force you to do)? This construct seems quite frequent in OCaml code. Thanks!

    Read the article

  • Using apt-get from Canada

    - by Advant Edge
    I am using Ubuntu Server 12.04 LTS, and until yesterday, everything was quite peachy. I have installed several packages (MySQL, apache2) and to my knowledge have those configured correctly. Upon configuration of phpMyAdmin, I found that I was missing the directory path /etc/phpmyadmin, which got me thinking about the install. I am new to Ubuntu, so I guess I missed the message telling me that I did not download phpMyAdmin successfully. Anyway, trying to use apt-get yesterday/today results in "Failed to fetch..." messages, even if just to run sudo apt-get update. Some notable details: ···no GUI, command line only (sudo apt-get gksu fails, go figure) ···can ping 4.2.2.2, so I know the internet is out there (somewhere) ···this is a dedicated computer, using Samba to share files with Windows, which does work ···attempted to edit my /sources.list file, for various American/Canadian mirror, to no effect ···ensured I have correct DNS settings in /etc/networks/interfaces I'm not sure where along the way it happened, but I seem to have lost connections to repositories... :) Any advice (including GO BACK TO WINDOWS) is appreciated.

    Read the article

  • What are the use cases for closures/callback functions in Javascript?

    - by Christopher Altman
    I was listening to Crockford's talk on Javascript closures and am convinced of the benefit of information hiding, but I do not have a firm understanding of when to use callback functions. It is mostly a true statement that a person could accomplish the same functionality with or without callbacks. As someone who is writing code, what heuristics or cues should I keep in mind when determining when to use callbacks/closures? I am not looking for the blanket statement 'Closures make more secure code', rather a list of practical examples or rules of thumb for when callbacks are the right idea. Crockford's Presentation: http://www.yuiblog.com/blog/2010/04/08/video-crockonjs-5/

    Read the article

  • Why do i get exc bad access in cases when object is not nil?

    - by DixieFlatline
    I have an app that receives remote notifications. My view controller that is shown after push has a tableview. App crashes very randomly (1 in 20 tries) at line setting frame: if (!myTableView) { NSLog(@"self.myTableView is nil"); } myTableView.frame=CGRectMake(0, 70, 320, 376); This only happens when i open the app, then open some other apps and then receive the push notification. I guess it has something to do with memory. I use ARC (ios 5). The strange thing is that nslog is not displayed, so tableview is not nil. Crash log: Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x522d580c Crashed Thread: 0 Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 libobjc.A.dylib 0x352b1f7e objc_msgSend + 22 1 Foundation 0x37dc174c NSKVOPendingNotificationCreate + 216 2 Foundation 0x37dc1652 NSKeyValuePushPendingNotificationPerThread + 62 3 Foundation 0x37db3744 NSKeyValueWillChange + 408 4 Foundation 0x37d8a848 -[NSObject(NSKeyValueObserverNotification) willChangeValueForKey:] + 176 5 Foundation 0x37e0ca14 _NSSetPointValueAndNotify + 76 6 UIKit 0x312af25a -[UIScrollView(Static) _adjustContentOffsetIfNecessary] + 1890 7 UIKit 0x312cca54 -[UIScrollView setFrame:] + 548 8 UIKit 0x312cc802 -[UITableView setFrame:] + 182 9 POViO 0x000913cc -[FeedVC viewWillAppear:] (FeedVC.m:303) Dealloc is not called because it is not logged: - (void)dealloc { NSLog(@"dealloc"); }

    Read the article

  • Have you been in cases where TDD increased development time?

    - by BillyONeal
    Hello everyone :) I was reading http://stackoverflow.com/questions/2512504/tdd-how-to-start-really-thinking-tdd and I noticed many of the answers indicate that tests + application should take less time than just writing the application. In my experience, this is not true. My problem though is that some 90% of the code I write has a TON of operating system calls. The time spent to actually mock these up takes much longer than just writing the code in the first place. Sometimes 4 or 5 times as long to write the test as to write the actual code. I'm curious if there are other developers in this kind of a scenario.

    Read the article

  • Why are there so many man-made edge cases in IT, and is there any hope for simplification / unificat

    - by Hamish Grubijan
    This question is meant to generate discussion and so it is marked as community wiki. My observation is that the field of information technology grows so rapidly and randomly, that for many it takes a lot of time to learn many intricacies of some tools that will be obsolete in just short 3 years. If you look at the questions asked on StackOverflow ... at least half of them stem from the fact that some language / tool / API / protocol was poorly designed, is backwards and has gotchas. There are so many things which distract developers from converting English into machine code; instead they spend their time configuring stuff and gluing together things that do not really fit. How many times do you pick up somebody else's project (or someone picks up yours :) ) and realize that this program does not need half of the dialogs that it has, and that the logic can be simplified a great deal? But, it had to be made and sold here before a better thing is made and sold elsewhere, and hence all this rush. I often wish that things would just slow down. I do not want Microsoft Windows to run on my car's computer, my watch, my table, my toaster oven, and my toilet seat. I'd rather have Windows that DOES NOT HAVE WINDOWS REGISTRY, I'd rather have Windows that allows two different programs to work on the same file at the same time, the way it works on Unix systems. Microsoft is just an example. I am looking forward to the day when I do not have to worry about Windows vs Unix new line break, when System32 actually means that this directory contains 32-bit binaries, and not 64-bit ones, the day when dll hell and manifest hell are no longer an issue, the day when it takes me a lot less than 3 months on a new job to learn the system. I do not mean learning the entire code base of a product (depending on the size of it, it can take a long time). I mean - remembering which build-assisting scripts are written in Perl and which version of it, and which ones are done through .bat files, when do I need to manually make every file in some directory writable before running a script, or else a critical step of a database maintenance home-grown tool will bomb, and it will take 2 days to clean that up. Makes me wonder if humans enslaved computers, or if it is the other way around. The key is that improving those things will not bring extra revenue, and hence those taking the time to fix crap like that are not "business focused". However, these imperfections irritate me immensely, particularly because my memory is limited - I can hold only a small portion of that useless knowledge of a system in my head at any given point in time. I must not be alone. Did you also happen to notice that a programmer can waste a lot of time on things that should have been a lot more straight-forward? Is there hope? Will things get better/simpler in the future, or will there be a lot more IT crap floating around? I suppose I see diversity of tools, protocols, etc. as a bad thing. Thank you for participation.

    Read the article

  • What are the use cases for this static reflection code?

    - by Maslow
    This is Oliver Hanappi's static reflection code he posted on stackoverflow private static string GetMemberName(Expression expression) { switch (expression.NodeType) { case ExpressionType.MemberAccess: var memberExpression = (MemberExpression)expression; var supername = GetMemberName(memberExpression.Expression); if (String.IsNullOrEmpty(supername)) return memberExpression.Member.Name; return String.Concat(supername, '.', memberExpression.Member.Name); case ExpressionType.Call: var callExpression = (MethodCallExpression)expression; return callExpression.Method.Name; case ExpressionType.Convert: var unaryExpression = (UnaryExpression)expression; return GetMemberName(unaryExpression.Operand); case ExpressionType.Parameter: return String.Empty; default: throw new ArgumentException("The expression is not a member access or method call expression"); } } I have the public wrapper methods: public static string Name<T>(Expression<Action<T>> expression) { return GetMemberName(expression.Body); } public static string Name<T>(Expression<Func<T, object>> expression) { return GetMemberName(expression.Body); } then added my own method shortcuts public static string ClassMemberName<T>(this T sourceType,Expression<Func<T,object>> expression) { return GetMemberName(expression.Body); } public static string TMemberName<T>(this IEnumerable<T> sourceList, Expression<Func<T,object>> expression) { return GetMemberName(expression.Body); } What are examples of code that would necessitate or take advantage of the different branches in the GetMemberName(Expression expression) switch? what all is this code capable of making strongly typed?

    Read the article

  • Do you know of a bleeding-edge HTML5 leveraging, legacy-ignoring JavaScript framework?

    - by Ivan
    What's the best framework (sort of jquery, extjs, etc like) to use if I'd like to intensively use all the freshest technologies of the HTML5 stack provided by modern browsers (Firefox 3.6+ (Minefield especially), Safari 4+, Chrome 4+) and have absolutely no need to support any legacy browsers (incl. no need in IE support at all, no need in Firefox prior to 3.5, etc.)? I'd like to get all the newest available goodness without having (even abstracted by a library layer) a line of code meant just fore legacy compatibility and keeping no legacy-induced things in mind. To soften the filter, taking very humble hope of such an ideally fresh framework to exist, the least (the maximum level of legacy support) I'd like to agree is not supporting IE versions older than IE8, or better just not supporting IE at all.

    Read the article

  • Why do Java/C# edge out C++ as the recommended language to learn OOP on S.O?

    - by viksit
    I noticed after reading the answers/discussion to this question (What is the best language to learn OOP on?) - that more and more people are recommending C# or Java over C++ to learn OOP on. A simple term search on that answer page results in 10 hits for C++, 21 for C# and 27 for Java. Now, I understand that these 2 languages fix a lot of quirks and issues with C++, and looked up these resources that relate mostly to performance, JVM vs native implementation, systems focus vs applications, manual memory management vs automated et al. My question is - are there any fundamental differences in the OO capabilities of Java/C# vs C++? Or are the former recommended purely due to their generic ease of use/improvements over the latter? Thanks. PS, I'm aware of Java interface inheritance vs C++ multiple inheritance as a difference. I would consider that an implementational one rather than functional.

    Read the article

  • Implementation of MVC with SQLite and NSURLConnection, use cases?

    - by user324723
    I'm interested in knowing how others have implemented/designed database & web services in their iphone app and how they simplified it for the entire application. My application is dependent on these services and I can't figure out a efficient way to use them together due to the (semi)complexity of my requirements. My past attempts on combining them haven't been completely successful or at least optimal in my mind. I'm building a database driven iphone app that uses a relational database in sqlite and consumes web services based on missing content or user interaction. Like this hasn't been done before...right? Since I am using a relational database - any web services consumed requires normalization, parsing the result and persisting it to the database before it can be displayed in a table view controller. The applications UI consists of nested(nav controller) table views where a user can select a cell and be taken to the next table view where it attempts to populate the table views data source from the database. If nothing exists in the database then it will send a request via web services to download its content, thus download - parse - persist - query - display. Since the user has the ability to request a refresh of this data it still requires the same process. Quickly describing what I've implemented and tried to run with - 1st attempt - Used a singleton web service class that handled sending web service requests, parsing the result and returning it to the table view controller via delegate protocols. Once the controller received that data it would then be responsible for persisting it to the database and re-returning the result. I didn't like the idea of only preventing the case where the app delegate selector doesn't exists(released) causing the app to crash. 2nd attempt - Used NSNotificationCenter for easy access to both database and web services but later realized it was more complex due to adding and removing observers per view(which isn't advised anyways).

    Read the article

  • How to smooth the edge of a zig-zag line?

    - by Horace Ho
    Currently I draw a zig-zap line by CGContextMoveToPoint, CGContextAddLineToPoint, and CGContextStrokePath, following touchesMoved events. How can I smooth the edges of the line? Such that when the user draw a circle-like shape, the circle can be more round'ed. The GLPaint example use OpenGL, is that the only way to do it?

    Read the article

  • How can I align the left edge of HTML form elements using CSS?

    - by Naor
    I want to do the following: aa: ________ bbbb: ________ ccc: ________ So I wrote: <span>aa:</span><input type="text" /><br/> <span>bbbb:</span><input type="text" /><br/> <span>cc:</span><input type="text" /> And I get: aa:________ bbbb:________ ccc:________ I know I can arrange it easy with table. How do I do it without tables with as few css as I can. Thanks.

    Read the article

  • What is the preferred way to indent cases in a switch?

    - by neutrino
    Hey there, As I was writing another switch in Eclipse, I once again came across a rather weird (to me, at least) default indentation, which is applied to 'switch' statements: switch (i) { case 1: ... case n: ... } I tend to prefer another way: switch (i) { case 1: ... case n: ... } Which way is more readable and eye-pleasing for you? I'm still not hundred percent determined what's best for me, so I'd like to stick to what's best for other people who would read my code. BTW, you're free to close this question if this is too subjective. :)

    Read the article

  • FlockDB - What is it? And best cases for it uses.

    - by Guru
    Just came across FlockDB graph database. Details at github /flockDB. Twitter claims it uses FlockDB for the following: Twitter runs FlockDB on a large cluster of machines. we use it to store social graphs (who follows whom, who blocks whom) and secondary indices at twitter. At first glance, setup and trying it doesn't look straight forward. Have anyone already used it / setup this? If so, please answer the following general queries. What kind of applications is it better suited for? (Twitter claims it is simple and very rough, it remains to see what it meant though) How is FlockDB better than other graph db / noSQL db. Have you setup FlockDB, used it for a application? Early advices any? Note: I am evaluating the FlockDB and other graph databases mainly for learning them. Perhaps, I will build an application for that.

    Read the article

  • Should you always write code for else cases that "can never happen"?

    - by johnswamps
    Take some code like if (person.IsMale()) { doGuyStuff(); } else { doGirlOtherStuff(); } (Yes, I realize this is bad OO code, it's an example) Should this be written so that to explicitly check if person.isFemale(), and then add a new else that throws an exception? Or maybe you're checking values in an enum, or something like that. You think that no one will add new elements to the enum, but who knows? "Can never happen" sounds like famous last words.

    Read the article

  • Document conversion and viewing, what are the cutting edge solutions?

    - by DigitalLawyer
    Goal: building a web application where a user can: Upload a document (doc, docx, pdf, additional office formats a +) View that document in a browser, preferably in html Download the document (in doc, pdf, additional open formats a +) Current solution: Ruby on Rails Application on Rackspace Users can upload doc and pdf files (AWS) Files can be downloaded in the format in which they were uploaded Thumbnail generation ([doc, pdf] - pdf - png) is done through AbiWord. Certain doc files do not convert well. Documents can be viewed in embedded Google docs viewer (https://docs.google.com/viewer). Certain doc files cannot be displayed. Little flexibility. Potential improvements: Document viewing in pdf through pdf.js Viewing in html (+ annotation) through Crocodoc I'd be glad to hear other users' experiences, and will add good recommendations to this list.

    Read the article

  • Rails 3 - raw/html_safe not working in some cases?

    - by Frexuz
    I'm having difficulties with output not being encoded even though I'm using raw or html_safe. This one is writing out the &nbsp in my final HTLM page. def build_tag_cloud(tag_cloud, style_list) tag_cloud.sort!{ |x,y| x.permalink <=> y.permalink } max, min = 0, 0 tag_cloud.each do |tag| max = tag.followers.to_i if tag.followers.to_i > max min = tag.followers.to_i if tag.followers.to_i < min end divisor = ((max - min) / style_list.size) + 1 html = "" tag_cloud.each do |tag| name = raw(tag.name.gsub('&','&amp;').gsub(' ','&nbsp;')) link = raw(link_to "#{name}", {:controller => "/shows", :action => "show", :permalink => tag.permalink}, :class => "#{style_list[(tag.followers.to_i - min) / divisor]}") html += raw("<li>#{link}</li> ") end return raw(html.to_s) end What is allowed in using raw and html_safe? And how should my example above be fixed?

    Read the article

< Previous Page | 10 11 12 13 14 15 16 17 18 19 20 21  | Next Page >