Search Results

Search found 26810 results on 1073 pages for 'fixed point'.

Page 932/1073 | < Previous Page | 928 929 930 931 932 933 934 935 936 937 938 939  | Next Page >

  • rbind.zoo doesn't seem create consistent zoo object

    - by a-or-b
    I want to rbind.zoo two zoo object together. When I was testing I came across the following issue(?)... Note: The below is an example, there is clearly no point to it apart from being illustrative. I have an zoo object, call it, 'X'. I want to break it into two parts and then rbind.zoo them together. When I compare it to the original object then all.equal gives differences. It appears that the '$class' attribute differs, but I can't see how or why. Is I make these xts objects then the all.equal works as expected. i.e. ..... X.date <- as.POSIXct(paste("2003-", rep(1:4, 4:1), "-", sample(1:28, 10, replace = TRUE), sep = "")) X <- zoo(matrix(rnorm(24), ncol = 2), X.date) a <- X[c(1:3), ] # first 3 elements b <- X[c(4:6), ] # second 3 elements c <- rbind.zoo(a, b) # rbind into an object of 6 elements d <- X[c(1:6), ] # all 6 elements all.equal(c, d) # are they equal? ~~~~ all.equal gives me the following difference: "Attributes: < Component 3: Attributes: < Length mismatch: comparison on first 1 components "

    Read the article

  • Matrix multiplication using pairs

    - by sc_ray
    Hi, I am looking into alternate ways to do a Matrix Multiplication. Instead of storing my matrix as a two-dimensional array, I am using a vector such as vector<pair<pair<int,int >,int > > to store my matrix. The pair within my pair (pair) stores my indices (i,j) and the other int stores the value for the given (i,j) pair. I thought I might have some luck implementing my sparse array this way. The problem is when I try to multiply this matrix with itself. If this was a 2-d array implementation, I would have multiplied the matrix as follows: for(i=0; i<row1; i++) { for(j=0; j<col1; j++) { C[i][j] = 0; for(k=0; k<col2; k++) C[i][j] += A[i][j] * A[j][k]; } } Can somebody point out a way to achieve the same result using my vector of 'pair of pairs'? Thanks

    Read the article

  • Write to the second line of a PHP file

    - by Woz
    I have a php file that I want to add an include path to on the second line. I need to open the file and inset a line of code on line 2. I have tried a few techniques none of which are working but I think it has something to do with the text I am trying to write and possibly not escaping character correctly as I am not too familiar with file writing. So here is the file I want to write to: $file = $_SERVER['DOCUMENT_ROOT'].'/'.$domaindir.'/test.php'; Here is the piece of text I want to insert into the file: $dbfile = "include('".$_SERVER['DOCUMENT_ROOT']."/".$domaindir."/web_".$dbname.".inc.php');"; Then what I was doing was a string replace but all it did was bump the "session_start();" bit to a newline! Can anyone point me in the direction of a tutorial that might tell me how to insert this into the second line of my php file or indeed if anyone has any ideas? I can say for sure that the path to the PHP file is fully tested so i know its not that the file is not being open or written to. Any ideas would be much appreciated. Thanks in advance.

    Read the article

  • Accessing appropriate array of double arrays in order of last created.

    - by Zach
    I have an array of double arrays, they are within a specified time window (8am-5pm), and are in order of last created over a period of several days. They are all timestamped and as such I have access to all C# DateTime methods. I then have a different iterative function that goes in the same order of the array of double arrays, however it isn't within a specified time window, it's 24/7. I want to access from this iterative function, the appropriate double array from the one within the window. Let's say that it's 4:30PM on DayOfYear 52, I'd like to access the last double array less than or equal to 4:30PM on DayOfYear 52. I'd expect the same double array if the time were 12:30AM on DayOfYear 53. However, if it were 9:00 AM of DayOfYear 53, well then I'd expect it to return something from the DayOfYear 53, less than or equal to 9:00AM. I think you get the idea. So I'm a having a bit of trouble grokking how to do this. Is anyone willing to offer a starting point or how they'd approach it? Edit: It is not a literal double[][], it is exactly as Anthony Pegram says: Dictionary<DateTime, double[]>

    Read the article

  • C++: recursively computer all permutaions of digits 0 - 9

    - by Nate
    I have a homework assignment where part of the requirement is to recursively compute all the permutations of integers 0 - 9. The professor actually gave us the algorithm for this part of the question. I've finished the rest of the assignment, but I can't get the permute function working...I'm implementing it exactly like it was shown on the assignment information. However, when I run it each permutation is repeated multiple times (and I'm not sure if I'm even getting all the correct permutations.) I think he must've made a mistake on the assignment instructions. I've been working on this for a couple of hours and can't seem to figure out where I'm going wrong. Can anybody help point me in the right direction? Here's the current code: void permute(int v[], int curr) { for (int i = curr; i < MAX; i++) { swap(v[i], v[curr]); permute(v, curr + 1); swap(v[curr], v[i]); } } EDIT: Actually, right after posting this I realized it has to do with the swap, right? Because right now i and curr are the same, so I'm swapping identical numbers. Hm, should it be swap(v[i], v[curr+1])?

    Read the article

  • Getting Junk characters while trying to print the file contents using Java

    - by user1523797
    I am reading a file's contents and trying to print the contents using java. But it prints junk characters along with the file content. Code: import java.io.*; public class ReadFile { public String readFile(String filePath){ StringBuilder contents = new StringBuilder(); File file = new File(filePath); try{ String lines = null; FileReader fileReader1 = new FileReader(file); BufferedReader buffer = new BufferedReader(fileReader1); while((lines = buffer.readLine())!=null){ contents.append(lines); } buffer.close(); } catch(FileNotFoundException ex){ System.out.println("File not found."); }catch(IOException ex){ System.out.println("Exception ocurred."); } return contents.toString(); } public static void main(String[] args){ ReadFile rf = new ReadFile(); String lines = rf.readFile("C:\\Data\\FaultDn.txt"); System.out.println("Original file contents: " + lines); } } The file contents are: partner.cisco.com:org-root/mac-pool-QA_MAC_Pool_5-Sep-2012_12:00 The output is: ![Alt Output](C:\Users\safarhee\Desktop\Output.jpg) Can you please point me to what I am missing in this code?

    Read the article

  • Help with a loop to return UIImage from possible matches

    - by Canada Dev
    I am parsing a list of locations and would like to return a UIImage with a flag based on these locations. I have a string with the location. This can be many different locations and I would like to search this string for possible matches in an NSArray, and when there's a match, it should find the appropriate filename in an NSDictionary. Here's an example of the NSDictionary and NSArray: NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys: @"franceFlag", @"france", @"greeceFlag", @"greece", @"spainFlag", @"spain", @"norwayFlag", @"norway", nil]; NSArray *array = [NSArray arrayWithObjects: @"france" @"greece" @"spain" @"portugal" @"ireland" @"norway", nil]; Obviously I'll have a lot more countries and flags in both. Here's what I have got to so far: -(UIImage *)flagFromOrigin:(NSString *)locationString { NSRange range; for (NSString *arrayString in countryArray) { range = [locationString rangeOfString:arrayString]; if (range.location != NSNotFound) { return [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[dictionary objectForKey: arrayString] ofType:@"png"]]; } } return nil; } Now, the above doesn't actually work. I am missing something (and perhaps not even doing it right in the first place) The issue is, the locationString could have several locations in the same country, described something like this "Barcelona, Spain", "Madrid, Spain", "North Spain", etc., but I just want to retrieve "Spain" in this case. (Also, notice caps for each country). Basically, I want to search the locationString I pass into the method for a possible match with one of the countries listed in the NSArray. If/When one is found, it should continue into the NSDictionary and grab the appropriate flag based on the correct matched string from the array. I believe the best way would then to take the string from the array, as this would be a stripped-out version of the location. Any help to point me in the right direction for the last bit is greatly appreciated.

    Read the article

  • Should I have one dll or multiple for Business Logic?

    - by Brian
    In my situation, my company services many types of customers. Almost every customer requires their own Business Logic. Of course, there will be a base layer that all business logic should inherit from. However, I'm going back and forth on architecting this--either in one dll for all customers or one dll for each. My biggest point of contention deals with upgrading the software. We have about 12 data entry personnel that work with 20 companies and it's critical that they have little down time. My concern is that if I deploy everything in one dll, I could introduce a bug in company A's logic while only intending to update Company B's logic. I believe I could reduce the risk if each company's logic had their own dll, so then, I could deploy Company B's update w/o harming Company A's. -- I will be the only one supporting this. That said, this also seems like a nightmare to manage 20 different .dll's -- that's for the BLL alone. I also need to create a View layer and ViewModel layer. So, potentially, I could have 20 (companies) * 3 (layers) which would equate to 60 .dll's. Thank You.

    Read the article

  • Best way to update/insert into a table based on a remote table.

    - by martilyo
    I have two very large enterprise tables in an Oracle 10g database. One table keeps the historical information of the other table. The problem is, I'm getting to the point where the records are just too many that my insert update is taking too long and my session is getting killed by the governor. Here's a pseudocode of my update process: sqlsel := 'SELECT col1, col2, col3, sysdate FROM table2@remote_location dpi WHERE (col1, col2, col3) IN ( SELECT col1, col2, col3 FROM table2@remote_location MINUS SELECT DISTINCT col1, col2, col3 FROM table1 mpc WHERE facility = '''||load_facility||''' )'; EXECUTE IMMEDIATE sqlsel BULK COLLECT INTO table1; I've tried the MERGE statement: MERGE INTO table1 t1 USING ( SELECT col1, col2, col3 FROM table2@remote_location ) t2 ON ( t1.col1 = t2.col1 AND t1.col2 = t2.col2 AND t1.col3 = t2.col3 ) WHEN NOT MATCHED THEN INSERT (t1.col1, t1.col2, t1.col3, t1.update_dttm ) VALUES (t2.col1, t2.col2, t2.col3, sysdate ) But there seems to be a confirmed bug on versions prior to Oracle 10.2.0.4 on the merge statement when doing a merge using a remote database. The chance of getting an enterprise upgrade is slim so is there a way to further optimize my first query or write it in another way to have it run best performance wise? Thanks.

    Read the article

  • WP7 help with menu effects

    - by MattMacdonald
    Kinda new to Silverlight and have some experience with WPF but I'm doing a project with a group for a class making a game for WP7. I am currently in charge of the menu system for the game and I had a few ideas for "flashy" menu transitions. I got some going for the main menu but I wanted to do something cool for the options submenu. Anyway my idea is to either fashion an expander or to have sort of a variation of a dialog box. But the way I envisioned it would be in either case the menu items blur but are still visible while the expanded menu is displayed or while the dialog is active. If I'm being confusing sorry :) but think of Windows 7 glass effect on the menu while other options are available. What I'm getting at is I want to give this a shot but I have no idea how I would go about doing something like this. Could anyone point me in the right direction or outline some key steps for me to build off? I tried finding something like this on Google but no such luck.

    Read the article

  • [javascript] Populating jsTree based on XML data uploaded to server folder

    - by PFM
    tl:dr How can I populate jsTree based on a folder location instead of an exact XML url? I'm looking for a little direction on this project. Currently I am trying to copy file structures of hard drives as XML files and recreate them using jsTree on the webserver for a completely independent version of the file structure. I have some python script that outputs XML files that are formed to jsTree and automatically uploads to a folder on the server. The problem is now I am a little lost because I have to manually enter each XML file into jsTree code for it to display so I have multiple entries like this: $("#tree1") .jstree({ "plugins" : [ "themes", "xml_data", "ui", "search", "types" ], "xml_data" : { "ajax" : { "url" : "./XML_DATA/DRIVE1.xml" }, "xsl" : "nest" }, I see in the documentation that instead of populated by the direct file the folders are populated by "server.php" but no where in the php code does it point to any directories or files. After considering the problem I thought of a few solutions and could use some advice on them: Should I be trying to write php code to automatically look through my XML_DATA folder to upload each XML file? Should I just upload all the XML to mySQL and populate my tree based on that? Should the javascript be the code looking through the server's folder for XML files? All the XML is formed the same way but the number of XML files on the server will increase and will have to be refreshed as well as they will be overwritten with changes. Any direction would be appreciated, thanks.

    Read the article

  • Running Sitecore Production Site under a Virtual Directory

    - by danswain
    We are using Sitecore 6 on a Windows Server 2003 (32bit) dev machine. I know it's not recommended for the CMS editing site, but we've been told it is possible to get the front-end Sitecore websites to run from within a virtual directory. Here's the issue: we'd like to achieve what the below poor mans diagram shows. We have a website (.net 1.1) /WebSiteRoot (.net 1.1) | | |---- Custom .net 1.1 Web Application | |---- SiteCore frontend WebApplication (.net 2.0) | |---- Custom .net 2.0 WebApplication The Sitecore webApplication would contain the Sitecore pipeline in its web.config and we'd make use of the section to configure the virtual folder to allow for where our Sitecore app sits and point it to the appropriate place in the Content Tree. Is it possible to pull this off? This is just the customer facing website, there will be no CMS editing functionality on these servers, that will be done from a more standard Sitecore install inside the firewall on a different server. The errors we're encountering are centered around loading the the various config files in the App_Config folder. It seems to do a Server.MapPath on "/" initially (which is wrong for us) so we've tried putting absolute paths in the web.config and still no joy (I think there must be some hardcoded piece that looks for the Include directory). Any help would be greatly appreciated. Thanks

    Read the article

  • some problem with iOS 4.2.1

    - by bicbac
    Hi, I've been developing an app with MacBook Pro (MBP) so far. Last week one of my friends gave me new macbook air 11"(MBA). so Now I can test my code with more than one machine with the same version of developing tools - Both machine has Xcode (3.2.5) and iOS SDK 4.2.1). After some point my app starts get terminated suddenly(iPhone sumulator), and I was using MBP. I got no error message whatsoever. it just stops. I reckon the crash comes from dealing with memory, like 'release'/ 'double-release'. (I'm not 100% sure though). Anyway I thought there must be some mistake within my code for sure. -Confusion starts from this part.- With my MBA, on the other hand, I don'y see any crash. It just works fine. There is nothing different between MBA & MBP except the h/w specifications. Same code, same versions of XCode and iOS SDK. Is the fact that no crash at MBA suggesting that I have to look somewhere else than the code itself? I red some article and Q&As on iOS4.2.1 and XCode 3.2.5 that the most recent version of XCode doesn't recognize the iOS 4.2.1 since the 4.2.1 came out later the 3.2.5. Is it the reason? I have no idea at this moment what should be the next move. thanks

    Read the article

  • Just 2 free months to learn or improve my skills

    - by microspino
    On the 30 of June I will leave my every day work to start as freelance developer. I'd like to set a period of 2 months apart to improve my dev skills. At work I code in C# and during my spare time I enjoyed building Ruby on Rails web applications and creating some Arduino prototypes. I'm something more than junior but I don't feel really a senior developer because I never had a big corporate project built and designed by me with help of other juniors (although I don't think this is really a good definiton of a "senior", It helps describing my feelings). Using a scale from 0 (ignorant) to 10 (proficient like a "samurai") the list below describes my skills that I would like to improve with just 2 months. I've already bought some nice and updated books on all the subjects hereunder: The order doesn't matter C = 1 C# & .Net = 6 Arduino & Processing = 2 Ruby = 5 Rails = 5 HTML/XHTML/CSS = 9 Javascript = 6 Objective-C/iPhone dev = 2 Python = 4 Django = 4 Desing Patterns = 3 Algorythms = 3 Git = 5 I haven't included SQL or Databases in general nor Networking because I spent 10 years working in the past with them and I feel pretty solid for now. As an aside, I've made up some interest in Redis, Node.js, HTML5 reading about them on the web. After two months, since I have to pay my bills, I could go searching for some new job. If learning and developing were really good maybe I could also invest on something I gave birth during them. Can You give me some piece of advice on which you think It's better to improve or develop a learning project on (something like a "summer of code" thing)? The all point Is to see my weaknesses and work on them.

    Read the article

  • ZendFramework Headscript Helper - Make scripts unique

    - by tokam
    How can I ensure that the headScript and headStyle helper include css files only once when added? The reason I am asking is that I would like to display some contents in a lightbox and all Flashmassages.E.g. notifications like profile successfully edited. To display flashmessages in the lightbox i would like to check at the top of my layout script if they are set, in case they are i would like to attach the required javascript library using the headScript helper. The problem is that I have no control about the scripts which were already added at this point. Maybe at a page where the library is needed for an other use case, it has already been added with addScript. How can I ensure all scripts are added only once to my helper? I already checked that these helpers extend Zend_View_Helper_Placeholder_Container_Standalone which uses an ArrayObject internally to hold the data and provides getters & setter to the array object. Maybe a solution here would be to check each time when adding a script file if it already exists using the ArrayObject?

    Read the article

  • fopen / fopen_s and writing to files

    - by yCalleecharan
    Hi, I'm using fopen in C to write the output to a text file. The function declaration is (where ARRAY_SIZE has been defined earlier): void create_out_file(char file_name[],long double *z1){ FILE *out; int i; if((out = fopen(file_name, "w+")) == NULL){ fprintf(stderr, "* Open error on output file %s", file_name); exit(-1); } for(i = 0; i < ARRAY_SIZE; i++) fprintf(out, "%.16Le\n", z1[i]); fclose(out); } My questions: On compilation with MVS2008 I get the warning: warning C4996: 'fopen': This function or variable may be unsafe. Consider using fopen_s instead. I haven't see much information on fopen_s so that I can change my code. Any suggestions? Can one instruct fprintf to write at desired precision? If I'm using long double then I assume that my answers are good till 15 digits after the decimal point. Am I right? Thanks a lot...

    Read the article

  • Is std::move really needed on initialization list of constructor for heavy members passed by value?

    - by PiotrNycz
    Recently I read an example from cppreference.../vector/emplace_back: struct President { std::string name; std::string country; int year; President(std::string p_name, std::string p_country, int p_year) : name(std::move(p_name)), country(std::move(p_country)), year(p_year) { std::cout << "I am being constructed.\n"; } My question: is this std::move really needed? My point is that compiler sees that this p_name is not used in the body of constructor, so, maybe, there is some rule to use move semantics for it by default? That would be really annoying to add std::move on initialization list to every heavy member (like std::string, std::vector). Imagine hundreds of KLOC project written in C++03 - shall we add everywhere this std::move? This question: move-constructor-and-initialization-list answer says: As a golden rule, whenever you take something by rvalue reference, you need to use it inside std::move, and whenever you take something by universal reference (i.e. deduced templated type with &&), you need to use it inside std::forward But I am not sure: passing by value is rather not universal reference?

    Read the article

  • measure the response time of a link

    - by Ahoura Ghotbi
    I am trying to create a simple load balance script and I was wondering if it is possible to find the response time of a server live? By that I mean is it possible to measure how long it takes for a server to respond after the request has been sent out? What I am trying to do is fairly simple, I want to send a request to a link/server and do a count down, if the server took more than 5 seconds to reply, I would like to fall on the backup server. Note that it doesnt have to be in pure php, I wouldnt mind using other languages such as javascript, C/C++, asp, but I prefer to do it in PHP. if it is possible to do the task, could you just point me to the right direction so I can read up on it. Clarification What I want to do is not to download a file and see how long it took, my servers have high load and it takes a while for them to respond when you click on a file to download, what I want to do is to measure the time it takes the server to respond (in this situation, its the time it takes the server to respond and allow the user to download the file), and if it takes longer than x seconds, it should fall back on a backup server.

    Read the article

  • Xml Conversion "Type mismatch" Error

    - by prema
    I am selecting a query in sql server 2005 SELECT 'Region' AS ELEMENT,(SELECT GeographyName,GeoID from @tmpTable FOR XML RAW, TYPE) FOR XML RAW('Root') This will give the output in xml as <Root ELEMENT="Region"> <row GeographyName="East" GeoID="2" /> <row GeographyName="West" GeoID="3" /> <row GeographyName="North" GeoID="4" /> <row GeographyName="South" GeoID="5" /> </Root> In aspx page, i want to get this function Populatedata(obj, val) { var xmlDom = new JXmlDom(obj, false); --> at this point i am getting error var nodeHeader = xmlDom.selectNodes("//row"); // my code goes here } function JXmlDom (xml,isFile) { this.load=load; this.loadXML=loadXML; this.selectNodes=selectNodes; this.text=text; this.selectSingleNode=selectSingleNode; this.documentElement=documentElement; this.transformNode=transformNode; if (isFile) { this.dom=this.load (xml); }else { this.dom=this.loadXML (xml); } function loadXML (xml) { if (window.ActiveXObject) { var dom=new ActiveXObject("Microsoft.XMLDOm"); dom.async=false; dom.loadXML (xml); } if (document.implementation && document.implementation.createDocument) { var domParser=new DOMParser(); var dom=domParser.parseFromString (xml,"text/xml"); } return dom; } But when i am calling this i am getting an error as Type mismatch.Can anyone help me

    Read the article

  • Java extends classes - Share the extended class fields within the super class.

    - by Bastan
    Straight to the point... I have a class public class P_Gen{ protected String s; protected Object oP_Gen; public P_Gen(String str){ s = str; oP_Gen = new Myclass(this); } } Extended class: public class P extends P_Gen{ protected Object oP; public P(String str){ oP = new aClass(str); super(str); } } MyClass: public class MyClass{ protected Object oMC; public MyClass(P extendedObject){ oMc = oP.getSomething(); } } I came to realize that MyClass can only be instantiated with (P_Gen thisObject) as opposed to (P extendedObject). The situation is that I have code generated a bunch of classes like P_Gen. For each of them I have generated a class P which would contains my P specific custom methods and fields. When I'll regenerate my code in the future, P would not be overwritten as P_Gen would. ** So what happened in my case???!!!... I realized that MyClass would beneficiate from the info stored in P in addition to only P_Gen. Would that possible? I know it's not JAVA "realistic" since another class that extends P_Gen might not have the same fields... BY DESIGN, P_Gen will not be extended by anything but P.... And that's where it kinda make sens. :-) at least in other programming language ;-) In other programming language, it seems like P_Gen.this === P.this, in other word, "this" becomes a combination of P and P_Gen. Is there a way to achieve this knowing that P_Gen won't be extended by anything than P?

    Read the article

  • Spring.net customer namespace parser

    - by ListenToRick
    I have a customer parser which looks like this: [NamespaceParser( Namespace = "http://mysite/schema/cache", SchemaLocationAssemblyHint = typeof(CacheNamespaceParser ), SchemaLocation = "/cache.xsd" ) ] public class CacheNamespaceParser : NamespaceParserSupport { public override void Init() { RegisterObjectDefinitionParser("cache", new CacheParser ()); } } public class CacheParser : AbstractSimpleObjectDefinitionParser { protected override Type GetObjectType(XmlElement element) { return typeof(CacheDefinition); } protected override void DoParse(XmlElement element, ObjectDefinitionBuilder builder) { } protected override bool ShouldGenerateIdAsFallback { get { return true; } } } in the web config i have the following configuration.... <spring> <parsers> <parser type="Spring.Data.Config.DatabaseNamespaceParser, Spring.Data"/> <parser type="App.Web.CacheNamespaceParser, WebApp" /> </parsers> When I run the project I get the following error: An error occurred creating the configuration section handler for spring/parsers: Invalid resource name. Name has to be in 'assembly:<assemblyName>/<namespace>/<resourceName>' format. I put a break point in the CacheNamespaceParser init method and it is called. If I remove from the web config all is well! Any ideas whats wrong

    Read the article

  • IE is stops Javascript with an error?

    - by Mahmoud
    hey there, i have complete of creating a javascript that well allow visitors ones the mouse is over the button a menu drops down, at some point on FireFox its working fine and also safari, but when it comes to IE it stops the script from running, where on the IE i debugged my script using IE debugger and i found out the error causing is frag+='<br /><li><form action="' + menuobj.items[i][1] + '" ><input type="submit" value="' + menuobj.items[i][0] + '" style="background-color:#000;border:hidden;color:#FFF"/></form></li><br />\n' for reference below is the full function code getmenuHTML:function(menuobj){ var menucontent=[] var frag="" for (var i=0; i < menuobj.items.length; i++){ frag+='<br /><li><form action="' + menuobj.items[i][1] + '" ><input type="submit" value="' + menuobj.items[i][0] + '" style="background-color:#000;border:hidden;color:#FFF"/></form></li><br />\n' if (menuobj.items[i][2]=="efc" || i==menuobj.items.length-1){ menucontent.push(frag) frag="" } } if (typeof menuobj.cols=="undefined") return '<ul>\n' + menucontent.join('') + '\n</ul>' else{ frag="" for (var i=0; i<menucontent.length; i++){ frag+='<div class="' + menuobj.cols.divclass + '" style="' + menuobj.cols.inlinestyle + '">\n<ul>\n' + menucontent[i] + '</ul>\n</div>\n' } return frag } },

    Read the article

  • When is it safe to use a broken hash function?

    - by The Rook
    It is trivial to use a secure hash function like SHA256 and continuing to use md5 is reckless behavior. However, there are some complexities to hash function vulnerabilities that I would like to better understand. Collisions have been generated for md4 and md5. According to NIST md5() is not a secure hash function. It only takes 2^39th operations to generate a collision and should never be used for passwords. However SHA1 is vulnerable to a similar collision attack in which a collision can be found in 2^69 operations, where as brute force is 2^80th. No one has generated a sha1 collision and NIST still lists sha1 as a secure message digest function. So when is it safe to use a broken hash function? Even though a function is broken it can still be "big enough". According to Schneier a hash function vulnerable to a collsion attack can still be used as an HMAC. I believe this is because the security of an HMAC is Dependant on its secret key and a collision cannot be found until this key is obtained. Once you have the key used in a HMAC its already broken, so its a moot point. What hash function vulnerabilities would undermine the security of an HMAC? Lets take this property a bit further. Does it then become safe to use a very weak message digest like md4 for passwords if a salt is perpended to the password? Keep in mind the md4 and md5 attacks are prefixing attacks, and if a salt is perpended then an attacker cannot control the prefix of the message. If the salt is truly a secret, and isn't known to the attacker, then does it matter if its a appended to the end of the password? Is it safe to assume that an attacker cannot generate a collision until the entire message has been obtained? Do you know of other cases where a broken hash function can be used in a security context without introducing a vulnerability? (Please post supporting evidence because it is awesome!)

    Read the article

  • Flash Player: Any remedy for the stale video image data problem (in a reused NetStream object)?

    - by amn
    Has anyone experienced stale stills of a previous playback for a reused NetStream object? If so, what are the workarounds for this, except re-creating the object (which eats performance and time)? It is hard to reuse NetStream objects because of a (in my opinion) fundamental issue with NetStream objects - when you 'close' a playing stream and at a later point issue a 'play' call on it again with a different name, the stream appears to still contain a stale image lingering from previous playback, and this is of course displayed in the Video object for a moment - the moment I assume it takes for new stream data to become available from server. Because of this behavior, to improve my users' visual experience, I simply discard a NetStream object after a playback session, and assign a new NetStream object to the same variable, set it up, and play something else. It appears to work - no stale image - but what bugs me is that it's a work around and costs performance (construction and setting up the object again - event listeners and 'client' delegates and more memory usage - NetStream objects are not garbage collected immediately, it takes some time). It would be really nice to REALLY be able to reuse a stream. I am thinking of something akin to Video.clear method, but for the NetStream class. Am I missing something?

    Read the article

  • paypal_adaptive gem in Rails: Dynamic Receiver "Population" (Chained Payments)

    - by Jmlevick
    Note: I didn't find a better title for this O.o Hello, Humm... Look, what I want to do is to have a Rails app where a visitor can click a button/link to make a "special" chained payment using Paypal; Currently I have a Users registration form that has one field for the user to enter his/her paypal account email, and as I saw here: http://marker.to/XGg9MR it is possible to specify the primary reciever and the secondary ones by adding such info in a controller action when using the paypal_adaptive gem in a rails app. The thing is, I don't want to hard code the secondary reciever as I need to specify a different secondary reciever from time to time, (being specific my primary reciever will always be the same, but depending on what button/link the visitor clicks, the secondary one is going to change) and I want that secondary reciever email to be the paypal e-mail account from one of the registered users when the visitor clicks on their specific button/link... My question is: Is it possible to create such enviroment functionality in my app using the current implementation of the paypal_adaptive gem? Could someone point me in the right direction on how to accomplish such thing? I'm still learning rails and also I'm really new in the paypal handling universe with this framework! XD P.S. Thanks! :)

    Read the article

< Previous Page | 928 929 930 931 932 933 934 935 936 937 938 939  | Next Page >