Search Results

Search found 6029 results on 242 pages for 'short circuit'.

Page 18/242 | < Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >

  • OpenID and Authlogic - login and password?

    - by skrat
    How can I get rid of validation messages telling me that: Login is too short (minimum is 3 characters) Login should use only letters, numbers, spaces, and .-_@ please. Password is too short (minimum is 4 characters) Password confirmation is too short (minimum is 4 characters) this happens even before map_openid_registration is called, thus not giving me any chance to fill login with something from returned registration Hash. I would like to have OpenID auto-registration (on login) without requiring user to supply login/password. I also won't make this fields "not required" or "not validated", since I still need them with old school login/password registration. Thank you

    Read the article

  • Correct way to Convert 16bit PCM Wave data to float

    - by fredley
    I have a wave file in 16bit PCM form. I've got the raw data in a byte[] and a method for extracting samples, and I need them in float format, i.e. a float[] to do a Fourier Transform. Here's my code, does this look right? I'm working on Android so javax.sound.sampled etc. is not available. private static short getSample(byte[] buffer, int position) { return (short) (((buffer[position + 1] & 0xff) << 8) | (buffer[position] & 0xff)); } ... float[] samples = new float[samplesLength]; for (int i = 0;i<input.length/2;i+=2){ samples[i/2] = (float)getSample(input,i) / (float)Short.MAX_VALUE; }

    Read the article

  • How does sizeof calculate the size of structures

    - by Gearoid Murphy
    I know that a char and an int are calculated as being 8 bytes on 32 bit architectures due to alignment, but I recently came across a situation where a structure with 3 shorts was reported as being 6 bytes by the sizeof operator. Code is as follows: #include <iostream> using namespace std ; struct IntAndChar { int a ; unsigned char b ; }; struct ThreeShorts { unsigned short a ; unsigned short b ; unsigned short c ; }; int main() { cout<<sizeof(IntAndChar)<<endl; // outputs '8' cout<<sizeof(ThreeShorts)<<endl; // outputs '6', I expected this to be '8' return 0 ; } Compiler : g++ (Debian 4.3.2-1.1) 4.3.2. This really puzzles me, why isn't alignment enforced for the structure containing 3 shorts?

    Read the article

  • Are bit operations quick?

    - by flashnik
    I'm dealing with a problem which needs to work with a lot of data. Currently its' values are represented as unsigned int. I know that real values do not exceed some limit, say 1000. That means that I can use unsigned short to store it. One profit is that it'll use less space. Do I have to pay for it by loosing in performance? Another assumption. I decided to store data as short but all calling functions use int, so I need to convert between these datatypes when storing/extracting values. Wiil the performance lost be dramatic? Third assumption. Due to great wish to econom memory I decided to use not short but just 10 bits packed into array of unsigned int. What will happen in this case comparing with previous ones?

    Read the article

  • How to parse a binary file using Javascript and Ajax

    - by Alex Jeffery
    I am trying to use JQuery to pull a binary file from a webserver, parse it in Javascript and display the contents. I can get the file ok and parse some of the file correctly. How ever I am running into trouble with one byte not coming out as expected. I am parsing the file a byte at a time, it is correct until I get to the hex value B6 where I am getting FD instead of B6. Function to read a byte data.charCodeAt(0) & 0xff; File As Hex: 02 00 00 00 55 4C 04 00 B6 00 00 00 The format I want to parse the file out into. short: 0002 short: 0000 string: UL short: 0004 long: 0000B6 Any hints as to why the last value is incorrect?

    Read the article

  • In Python, how to use a C++ function which returns an allocated array of structs via a ** parameter?

    - by Jon-Eric
    I'd like to use some existing C++ code, NvTriStrip, in a Python tool. SWIG easily handles the functions with simple parameters, but the main function, GenerateStrips, is much more complicated. What do I need to put in the SWIG interface file to indicate that primGroups is really an output parameter and that it must be cleaned up with delete[]? /////////////////////////////////////////////////////////////////////////// // GenerateStrips() // // in_indices: input index list, the indices you would use to render // in_numIndices: number of entries in in_indices // primGroups: array of optimized/stripified PrimitiveGroups // numGroups: number of groups returned // // Be sure to call delete[] on the returned primGroups to avoid leaking mem // bool GenerateStrips( const unsigned short* in_indices, const unsigned int in_numIndices, PrimitiveGroup** primGroups, unsigned short* numGroups, bool validateEnabled = false ); FYI, here is the PrimitiveGroup declaration: enum PrimType { PT_LIST, PT_STRIP, PT_FAN }; struct PrimitiveGroup { PrimType type; unsigned int numIndices; unsigned short* indices; PrimitiveGroup() : type(PT_STRIP), numIndices(0), indices(NULL) {} ~PrimitiveGroup() { if(indices) delete[] indices; indices = NULL; } };

    Read the article

  • Using typedefs (or #defines) on built in types - any sensible reason?

    - by jb
    Well I'm doing some Java - C integration, and throught C library werid type mappings are used (theres more of them;)): #define CHAR char /* 8 bit signed int */ #define SHORT short /* 16 bit signed int */ #define INT int /* "natural" length signed int */ #define LONG long /* 32 bit signed int */ typedef unsigned char BYTE; /* 8 bit unsigned int */ typedef unsigned char UCHAR; /* 8 bit unsigned int */ typedef unsigned short USHORT; /* 16 bit unsigned int */ typedef unsigned int UINT; /* "natural" length unsigned int*/ Is there any legitimate reason not to use them? It's not like char is going to be redefined anytime soon. I can think of: Writing platform/compiler portable code (size of type is underspecified in C/C++) Saving space and time on embedded systems - if you loop over array shorter than 255 on 8bit microprocessor writing: for(uint8_t ii = 0; ii < len; ii++) will give meaureable speedup.

    Read the article

  • How to Have a Bundled Configurable Product in Magento ??

    - by Calua
    Hi everybody, I've been searching about this topic on Magento forum and Google but can't find a definite answer for the question. Hope I find it here. Is it possible to have a bundled configurable products in Magento? Take for example I want to sell a set of t-shirt and short on a product page where the customer can choose the number of quantity, the color and the size for the t-shirt and short respectively. Maybe like this : T-Shirt [A configurable Product] Color : [combobox to select color] Size : [combobox to select Size] Qty : [input to enter the qty] Short [Another configurable Product] Color : [combobox to select color] Size : [combobox to select Size] Qty : [input to enter the qty] [Add to Cart Button] Any help and answer will be much appreciated. Thanks!

    Read the article

  • Do bit operations cause programs to run slower?

    - by flashnik
    I'm dealing with a problem which needs to work with a lot of data. Currently its values are represented as an unsigned int. I know that real values do not exceed a limit of 1000. Questions I can use unsigned short to store it. An upside to this is that it'll use less storage space to store the value. Will performance suffer? If I decided to store data as short but all the calling functions use int, it's recognized that I need to convert between these datatypes when storing or extracting values. Will performance suffer? Will the loss in performance be dramatic? If I decided to not use short but just 10 bits packed into an array of unsigned int. What will happen in this case comparing with previous ones?

    Read the article

  • Performance: float to int cast and clippling result to range

    - by durandai
    I'm doing some audio processing with float. The result needs to be converted back to PCM samples, and I noticed that the cast from float to int is surprisingly expensive. Whats furthermore frustrating that I need to clip the result to the range of a short (-32768 to 32767). While I would normally instictively assume that this could be assured by simply casting float to short, this fails miserably in Java, since on the bytecode level it results in F2I followed by I2S. So instead of a simple: int sample = (short) flotVal; I needed to resort to this ugly sequence: int sample = (int) floatVal; if (sample > 32767) { sample = 32767; } else if (sample < -32768) { sample = -32768; } Is there a faster way to do this? (about ~6% of the total runtime seems to be spent on casting, while 6% seem to be not that much at first glance, its astounding when I consider that the processing part involves a good chunk of matrix multiplications and IDCT)

    Read the article

  • How to Have a Bundled Configurable Product in Magento?

    - by Calua
    I've been searching about this topic on Magento forum and Google but can't find a definite answer for the question. Hope I find it here. Is it possible to have a bundled configurable products in Magento? Take for example I want to sell a set of t-shirt and short on a product page where the customer can choose the number of quantity, the color and the size for the t-shirt and short respectively. Maybe like this : T-Shirt [A configurable Product] Color : [combobox to select color] Size : [combobox to select Size] Qty : [input to enter the qty] Short [Another configurable Product] Color : [combobox to select color] Size : [combobox to select Size] Qty : [input to enter the qty] [Add to Cart Button] Any help and answer will be much appreciated. Thanks!

    Read the article

  • writing structs and classes to disk

    - by Phenom
    The following function writes a struct to a file. int btwrite(short rrn, BTPAGE *page_ptr) { long addr; addr = (long) rrn * (long) PAGESIZE + HEADERSIZE; lseek(btfd, addr, 0); return (write(btfd, page_ptr, PAGESIZE)); } The following is the struct. typedef struct { short keycount; /* number of keys in page */ int key[MAXKEYS]; /* the actual keys */ int value[MAXKEYS]; /* the actual values */ short child[MAXKEYS+1]; /* ptrs to rrns of descendants */ } BTPAGE; What would happen if I changed the struct to a class, would it still work the same? If I added class functions, would the size it takes up on disk increase?

    Read the article

  • What good books are out there on program execution models? [on hold]

    - by murungu
    Can anyone out there name a few books that address the topic of program execution models?? I want a book that can answer questions such as... What is the difference between interpreted and compiled languages and what are the performance consequences at runtime?? What is the difference between lazy evaluation, eager evaluation and short circuit evaluation?? Why would one choose to use one evaluation strategy over another?? How do you simulate lazy evaluation in a language that favours eager evaluation??

    Read the article

  • Linux on 8-bit

    - by nospam(at)example.com (Joerg Moellenkamp)
    This is nothing short of extremly cool from a technical perspective. The author has done it by writing an ARM emulator for an AVR controller and running Linux with this emulation : Linux on an 8-bit micro?.This is definitely not the fastest, but I think it may be the cheapest, slowest, simplest to hand assemble, lowest part count, and lowest-end Linux PC. The board is hand-soldered using wires, there is not even a requirement for a printed circuit board

    Read the article

  • Video: A Peek Inside the HTC Incredible Phone

    <b>Wired: </b>"TechRestore, an electronics repair shop, has taken apart the Incredible and then it put all back together. What's fascinating to watch in the video is how small and compact the components are and how well they pack into the circuit board."

    Read the article

  • JPA/EclipseLink multitenancy screencast

    - by alexismp
    I find JPA and in particular EclipseLink 2.3 to be particularly well suited to illustrate the concept of multitenancy, one of the key PaaS features en route for Java EE 7. Here's a short (5-minute) screencast showing GlassFish 3.1.1 (due out real soon now) and its EclipseLink 2.3 JPA provider showing multitenancy in action. In short, it adds EclipseLink annotations to a JPA entity and deploys two identical applications with different tenant-id properties defined in the persistence.xml descriptor. Each application only sees its own data, yet everything is stored in the same table which was augmented with a discriminator column. For more advanced uses such as tenant property being set on the @PersistenceContext, XML configuration of multitenant JPA entities, and more check out the nicely written wiki page.

    Read the article

  • What is the most efficient way to convert to binary and back in C#?

    - by Saad Imran.
    I'm trying to write a general purpose socket server for a game I'm working on. I know I could very well use already built servers like SmartFox and Photon, but I wan't to go through the pain of creating one myself for learning purposes. I've come up with a BSON inspired protocol to convert the the basic data types, their arrays, and a special GSObject to binary and arrange them in a way so that it can be put back together into object form on the client end. At the core, the conversion methods utilize the .Net BitConverter class to convert the basic data types to binary. Anyways, the problem is performance, if I loop 50,000 times and convert my GSObject to binary each time it takes about 5500ms (the resulting byte[] is just 192 bytes per conversion). I think think this would be way too slow for an MMO that sends 5-10 position updates per second with a 1000 concurrent users. Yes, I know it's unlikely that a game will have a 1000 users on at the same time, but like I said earlier this is supposed to be a learning process for me, I want to go out of my way and build something that scales well and can handle at least a few thousand users. So yea, if anyone's aware of other conversion techniques or sees where I'm loosing performance I would appreciate the help. GSBitConverter.cs This is the main conversion class, it adds extension methods to main datatypes to convert to the binary format. It uses the BitConverter class to convert the base types. I've shown only the code to convert integer and integer arrays, but the rest of the method are pretty much replicas of those two, they just overload the type. public static class GSBitConverter { public static byte[] ToGSBinary(this short value) { return BitConverter.GetBytes(value); } public static byte[] ToGSBinary(this IEnumerable<short> value) { List<byte> bytes = new List<byte>(); short length = (short)value.Count(); bytes.AddRange(length.ToGSBinary()); for (int i = 0; i < length; i++) bytes.AddRange(value.ElementAt(i).ToGSBinary()); return bytes.ToArray(); } public static byte[] ToGSBinary(this bool value); public static byte[] ToGSBinary(this IEnumerable<bool> value); public static byte[] ToGSBinary(this IEnumerable<byte> value); public static byte[] ToGSBinary(this int value); public static byte[] ToGSBinary(this IEnumerable<int> value); public static byte[] ToGSBinary(this long value); public static byte[] ToGSBinary(this IEnumerable<long> value); public static byte[] ToGSBinary(this float value); public static byte[] ToGSBinary(this IEnumerable<float> value); public static byte[] ToGSBinary(this double value); public static byte[] ToGSBinary(this IEnumerable<double> value); public static byte[] ToGSBinary(this string value); public static byte[] ToGSBinary(this IEnumerable<string> value); public static string GetHexDump(this IEnumerable<byte> value); } Program.cs Here's the the object that I'm converting to binary in a loop. class Program { static void Main(string[] args) { GSObject obj = new GSObject(); obj.AttachShort("smallInt", 15); obj.AttachInt("medInt", 120700); obj.AttachLong("bigInt", 10900800700); obj.AttachDouble("doubleVal", Math.PI); obj.AttachStringArray("muppetNames", new string[] { "Kermit", "Fozzy", "Piggy", "Animal", "Gonzo" }); GSObject apple = new GSObject(); apple.AttachString("name", "Apple"); apple.AttachString("color", "red"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.5); GSObject lemon = new GSObject(); apple.AttachString("name", "Lemon"); apple.AttachString("color", "yellow"); apple.AttachBool("inStock", false); apple.AttachFloat("price", (float)0.8); GSObject apricoat = new GSObject(); apple.AttachString("name", "Apricoat"); apple.AttachString("color", "orange"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.9); GSObject kiwi = new GSObject(); apple.AttachString("name", "Kiwi"); apple.AttachString("color", "green"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)2.3); GSArray fruits = new GSArray(); fruits.AddGSObject(apple); fruits.AddGSObject(lemon); fruits.AddGSObject(apricoat); fruits.AddGSObject(kiwi); obj.AttachGSArray("fruits", fruits); Stopwatch w1 = Stopwatch.StartNew(); for (int i = 0; i < 50000; i++) { byte[] b = obj.ToGSBinary(); } w1.Stop(); Console.WriteLine(BitConverter.IsLittleEndian ? "Little Endian" : "Big Endian"); Console.WriteLine(w1.ElapsedMilliseconds + "ms"); } Here's the code for some of my other classes that are used in the code above. Most of it is repetitive. GSObject GSArray GSWrappedObject

    Read the article

  • How to Write an E-Book

    A few days ago my attention was drawn to a tweet spat between Karl Seguin and Scott Hanselman around the relaunch of ASP.NET and the title element in HTML. Tempest in a teapot of course, but worthwhile as I did some googling on Karl and found his blog at codebetter.com. From there it was a short jump to his free e-book, The Foundations of Programming. This short book is distinguished by its orientation, opinionated, its tone, mentoring and its honesty, which is refreshing. In Foundations, Karl covers what he considers the basics of programming and good design, including test driven development, dependency injection and domain driven design. Karl is opinionated, as the topics suggest, and doesnt bother to pretend that he doesnt think what hes suggesting is the better way, not just another way. He is aligned with ALT.NET, and gives an excellent overview of what that means; an overview more enlightening than the ALT.NET site. ALT.NET has its critics, but presenting a strong opinion grabbed my attention as a reader. It is a short walk from opinionated to hectoring,  but Karl held my attention without insulting me. He takes the time to explain, with examples, from the ground up, the problems that test driven development and dependency injection solve. So for dependency injection he builds it up from no DI, to a hand crafted approach, to a full fledged DI framework. This approach is more persuasive than just proscriptive and engaged me as the reader to follow along with his train of thought. Foundations is not as pedantic as I am making it sound. The final ingredient in Karls mix is honesty. He acknowledges that sometimes unit testing does cost more up front and take more time. He admits that sometimes he designs something a certain way just to be testable. He also warns that focusing too much on DI and loose coupling can lead to the poor design you are trying to avoid. These points add depth to his argument as I could tell hes speaking from experience, with some hard won lessons. I enjoyed The Foundations of Programming. When I was done with it, I was amazed how much I got a lot out of its 80 some pages. It is a rarity to come across something worthwhile that is longer then a tweet, but shorter than a tome these days. Well done Karl.   -- Relevant Links -- The now titled and newly relaunched page in question: http://www.asp.net/ The pleasantly confusing ALT.NET homepage: http://altdotnet.org/ A longer review, with details, chapter listings and all that important stuff: http://accidentaltechnologist.com/book-reviews/book-review-foundations-of-programming-by-karl-seguin/Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • Help with dynamic range compression function (audio)

    - by MusiGenesis
    I am writing a C# function for doing dynamic range compression (an audio effect that basically squashes transient peaks and amplifies everything else to produce an overall louder sound). I have written a function that does this (I think): public static void Compress(ref short[] input, double thresholdDb, double ratio) { double maxDb = thresholdDb - (thresholdDb / ratio); double maxGain = Math.Pow(10, -maxDb / 20.0); for (int i = 0; i < input.Length; i += 2) { // convert sample values to ABS gain and store original signs int signL = input[i] < 0 ? -1 : 1; double valL = (double)input[i] / 32768.0; if (valL < 0.0) { valL = -valL; } int signR = input[i + 1] < 0 ? -1 : 1; double valR = (double)input[i + 1] / 32768.0; if (valR < 0.0) { valR = -valR; } // calculate mono value and compress double val = (valL + valR) * 0.5; double posDb = -Math.Log10(val) * 20.0; if (posDb < thresholdDb) { posDb = thresholdDb - ((thresholdDb - posDb) / ratio); } // measure L and R sample values relative to mono value double multL = valL / val; double multR = valR / val; // convert compressed db value to gain and amplify val = Math.Pow(10, -posDb / 20.0); val = val / maxGain; // re-calculate L and R gain values relative to compressed/amplified // mono value valL = val * multL; valR = val * multR; double lim = 1.5; // determined by experimentation, with the goal // being that the lines below should never (or rarely) be hit if (valL > lim) { valL = lim; } if (valR > lim) { valR = lim; } double maxval = 32000.0 / lim; // convert gain values back to sample values input[i] = (short)(valL * maxval); input[i] *= (short)signL; input[i + 1] = (short)(valR * maxval); input[i + 1] *= (short)signR; } } and I am calling it with threshold values between 10.0 db and 30.0 db and ratios between 1.5 and 4.0. This function definitely produces a louder overall sound, but with an unacceptable level of distortion, even at low threshold values and low ratios. Can anybody see anything wrong with this function? Am I handling the stereo aspect correctly (the function assumes stereo input)? As I (dimly) understand things, I don't want to compress the two channels separately, so my code is attempting to compress a "virtual" mono sample value and then apply the same degree of compression to the L and R sample value separately. Not sure I'm doing it right, however. I think part of the problem may the "hard knee" of my function, which kicks in the compression abruptly when the threshold is crossed. I think I may need to use a "soft knee" like this: Can anybody suggest a modification to my function to produce the soft knee curve?

    Read the article

  • Siebel Open UI Training for Oracle EMEA CRM Partners - Free - Utrecht NL- January 22/23 2012

    - by Richard Lefebvre
    Have you heard about Siebel Open UI? It is the new, state-of-the-art User Interface for Siebel, offering an amazing User Experience on any browser. Oracle is planning a free of charge 2 days training, delivered by Oracle Product Development specialists, in Utrecht (NL) on January 22&23 2012. Seats are very limited. If you or your colleagues are interested to apply for one, please send an eMail to [email protected] with the contact details of the individuals who you would like to nomminate. If you would like to know more about Siebl Open UI before applying, please send an eMail to [email protected] to receive a short PPT deck featuring a short Siebel Open UI description, its benefits for (System Integrators) partners, and the detailed agenda.  Selected Participants will then be invited to register via the Oracle APEX system.

    Read the article

  • How DNS Works [Video]

    - by Jason Fitzpatrick
    Want an easy and visual way to explain DNS to a curious friend or cubemate? This clean and simple short video does a great job highlighting exactly what goes on during a typical DNS request. Last month we explained what DNS is and showed you why you might want to use alternate DNS servers; this short video serves as an excellent visual companion for our article. How DNS Works [YouTube] 8 Deadly Commands You Should Never Run on Linux 14 Special Google Searches That Show Instant Answers How To Create a Customized Windows 7 Installation Disc With Integrated Updates

    Read the article

  • Best Ati Radeon x1200 drivers for 12.10

    - by Jaclyn
    [Long story short is at the bottom if you don't care about my ranting] Ok, well, I have the unfortunate distinction of having an Acer Extensa 4420 (Yes, the model with the faulty motherboard, and no, I do not know how it is still working either). Long story short I need the best drivers for my Ati Radeon x1200 integrated graphics card. The Ati Propriatary drivers for 12.10 no longer supports my video card. Currently when I try to play Minecraft, or any game really, the framerate is quite terrible despite the fact that my handy dandy system load monitor says that I have plenty of memory and CPU power (Mind you, this is when I'm not playing minecraft; that kind of uses up all of my resources unless it's on the worst graphical settings, and even then I have terrible framerate, but plenty of resources left over). I tried the fglrx through a workaround guide, and it completely killed my display and I had to uninstall it. I'm considering just trying to install fglrx through synaptic, but I am hesitant to do so since I don't want a repeat of the BSBDD!!! (Black Screen of Bad Drivers 'o DOOOM!!!), so I will wait until after I get some input from you fine ladies and gentlemen on to what your advice it. ok, so I'm running xubuntu 12.10 64 bit. I upgraded from 10.10 to 11.04. Then about a month ago I went from natty to quantal via the update option in the package updater, and then I decided that I was sick of gnome so I installed xfce. I did not install new drivers from natty to when I wound up at 12.10, so that shouldn't have changed, and they were indeed quite terrible back then, but now I'm using xubuntu as my main os, so I actually need good drivers. uuuugh. Anyway, long story short: I need to know what are the best drivers available for my card, and how to install them, because I am a linux novice, and I have tried everything that I can think of, including search google. Small edit: I forgot to note that since I upgraded to 12.10, my VGA out does not work (I haven't had a chance to try the s-video yet), and possibly related, the USB port on that side of my laptop does not work anymore either.

    Read the article

< Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >