Search Results

Search found 1995 results on 80 pages for 'retro computing'.

Page 62/80 | < Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >

  • Efficient 4x4 matrix inverse (affine transform)

    - by Budric
    Hi, I was hoping someone can point out an efficient formula for 4x4 affine matrix transform. Currently my code uses cofactor expansion and it allocates a temporary array for each cofactor. It's easy to read, but it's slower than it should be. Note, this isn't homework and I know how to work it out manually using 4x4 co-factor expansion, it's just a pain and not really an interesting problem for me. Also I've googled and came up with a few sites that give you the formula already (http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm). However this one could probably be optimized further by pre-computing some of the products. I'm sure someone came up with the "best" formula for this at one point or another? Thanks.

    Read the article

  • Compute bounding quad of a sphere with vertex shader

    - by Ben Jones
    I'm trying to implement an algorithm from a graphics paper and part of the algorithm is rendering spheres of known radius to a buffer. They say that they render the spheres by computing the location and size in a vertex shader and then doing appropriate shading in a fragment shader. Any guesses as to how they actually did this? The position and radius are known in world coordinates and the projection is perspective. Does that mean that the sphere will be projected as a circle? Thanks!

    Read the article

  • High volume SVM (machine learning) system

    - by flyingcrab
    I working on a possible machine learning project that would be expected to do high speed computations for machine learning using SVM (support vector machines) and possibly some ANN. I'm resonably comfortable working on matlab with these, but primarly in small datasets, just for experimentation. I'm wondering if this matlab based approach will scale? or should i be looking into something else? C++ / gpu based computing? java wrapping of the matlab code and pushing it onto app engine? Incidentally, there seems to be a lot fo literature on GPUs, but not much on how useful they are on machine learning applications using matlab, & the cheapest CUDA enlabled GPU money can buy? is it even worth the trouble?

    Read the article

  • 3 dimensional bin packing algorithms

    - by BuschnicK
    I'm faced with a 3 dimensional bin packing problem and am currently conducting some preliminary research as to which algorithms/heuristics are currently yielding the best results. Since the problem is NP hard I do not expect to find the optimal solution in every case, but I was wondering: 1) what are the best exact solvers? Branch and Bound? What problem instance sizes can I expect to solve with reasonable computing resources? 2) what are the best heuristic solvers? 3) What off-the-shelf solutions exist to conduct some experiments with?

    Read the article

  • Resulting .exe from PyInstaller with wxPython crashing

    - by Helgi Hrafn Gunnarsson
    I'm trying to compile a very simple wxPython script into an executable by using PyInstaller on Windows Vista. The Python script is nothing but a Hello World in wxPython. I'm trying to get that up and running as a Windows executable before I add any of the features that the program needs to have. But I'm already stuck. I've jumped through some loops in regards to MSVCR90.DLL, MSVCP90.DLL and MSVCPM90.DLL, which I ended up copying from my Visual Studio installation (C:\Program Files\Microsoft Visual Studio 9.0\VC\redist\x86\Microsoft.VC90.CRT). As according to the instructions for PyInstaller, I run: Command: Configure.py Output: I: computing EXE_dependencies I: Finding TCL/TK... I: could not find TCL/TK I: testing for Zlib... I: ... Zlib available I: Testing for ability to set icons, version resources... I: ... resource update available I: Testing for Unicode support... I: ... Unicode available I: testing for UPX... I: ...UPX available I: computing PYZ dependencies... So far, so good. I continue. Command: Makespec.py -F guitest.py Output: wrote C:\Code\PromoUSB\guitest.spec now run Build.py to build the executable Then there's the final command. Command: Build.py guitest.spec Output: checking Analysis building Analysis because out0.toc non existent running Analysis out0.toc Analyzing: C:\Python26\pyinstaller-1.3\support\_mountzlib.py Analyzing: C:\Python26\pyinstaller-1.3\support\useUnicode.py Analyzing: guitest.py Warnings written to C:\Code\PromoUSB\warnguitest.txt checking PYZ rebuilding out1.toc because out1.pyz is missing building PYZ out1.toc checking PKG rebuilding out3.toc because out3.pkg is missing building PKG out3.pkg checking ELFEXE rebuilding out2.toc because guitest.exe missing building ELFEXE out2.toc I get the resulting 'guitest.exe' file, but upon execution, it "simply crashes"... and there is no debug info. It's just one of those standard Windows Vista crashes. The script itself, guitest.py runs just fine by itself. It only crashes as an executable, and I'm completely lost. I don't even know what to look for, since nothing I've tried has returned any relevant results. Another file is generated as a result of the compilation process, called 'warnguitest.txt'. Here are its contents. W: no module named posix (conditional import by os) W: no module named optik.__all__ (top-level import by optparse) W: no module named readline (delayed, conditional import by cmd) W: no module named readline (delayed import by pdb) W: no module named pwd (delayed, conditional import by posixpath) W: no module named org (top-level import by pickle) W: no module named posix (delayed, conditional import by iu) W: no module named fcntl (conditional import by subprocess) W: no module named org (top-level import by copy) W: no module named _emx_link (conditional import by os) W: no module named optik.__version__ (top-level import by optparse) W: no module named fcntl (top-level import by tempfile) W: __all__ is built strangely at line 0 - collections (C:\Python26\lib\collections.pyc) W: delayed exec statement detected at line 0 - collections (C:\Python26\lib\collections.pyc) W: delayed conditional __import__ hack detected at line 0 - doctest (C:\Python26\lib\doctest.pyc) W: delayed exec statement detected at line 0 - doctest (C:\Python26\lib\doctest.pyc) W: delayed conditional __import__ hack detected at line 0 - doctest (C:\Python26\lib\doctest.pyc) W: delayed __import__ hack detected at line 0 - encodings (C:\Python26\lib\encodings\__init__.pyc) W: __all__ is built strangely at line 0 - optparse (C:\Python26\pyinstaller-1.3\optparse.pyc) W: __all__ is built strangely at line 0 - dis (C:\Python26\lib\dis.pyc) W: delayed eval hack detected at line 0 - os (C:\Python26\lib\os.pyc) W: __all__ is built strangely at line 0 - __future__ (C:\Python26\lib\__future__.pyc) W: delayed conditional __import__ hack detected at line 0 - unittest (C:\Python26\lib\unittest.pyc) W: delayed conditional __import__ hack detected at line 0 - unittest (C:\Python26\lib\unittest.pyc) W: __all__ is built strangely at line 0 - tokenize (C:\Python26\lib\tokenize.pyc) W: __all__ is built strangely at line 0 - wx (C:\Python26\lib\site-packages\wx-2.8-msw-unicode\wx\__init__.pyc) W: __all__ is built strangely at line 0 - wx (C:\Python26\lib\site-packages\wx-2.8-msw-unicode\wx\__init__.pyc) W: delayed exec statement detected at line 0 - bdb (C:\Python26\lib\bdb.pyc) W: delayed eval hack detected at line 0 - bdb (C:\Python26\lib\bdb.pyc) W: delayed eval hack detected at line 0 - bdb (C:\Python26\lib\bdb.pyc) W: delayed __import__ hack detected at line 0 - pickle (C:\Python26\lib\pickle.pyc) W: delayed __import__ hack detected at line 0 - pickle (C:\Python26\lib\pickle.pyc) W: delayed conditional exec statement detected at line 0 - iu (C:\Python26\pyinstaller-1.3\iu.pyc) W: delayed conditional exec statement detected at line 0 - iu (C:\Python26\pyinstaller-1.3\iu.pyc) W: delayed eval hack detected at line 0 - gettext (C:\Python26\lib\gettext.pyc) W: delayed __import__ hack detected at line 0 - optik.option_parser (C:\Python26\pyinstaller-1.3\optik\option_parser.pyc) W: delayed conditional eval hack detected at line 0 - warnings (C:\Python26\lib\warnings.pyc) W: delayed conditional __import__ hack detected at line 0 - warnings (C:\Python26\lib\warnings.pyc) W: __all__ is built strangely at line 0 - optik (C:\Python26\pyinstaller-1.3\optik\__init__.pyc) W: delayed exec statement detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed conditional eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed conditional eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) W: delayed eval hack detected at line 0 - pdb (C:\Python26\lib\pdb.pyc) I don't know what the heck to make of any of that. Again, my searches have been fruitless.

    Read the article

  • Windows Series Phone 7 "Cloud"

    - by user275561
    I have been reading up on "Cloud computing" on here and still not getting it. Basically I want to develop for the WP7 http://msdn.microsoft.com/en-us/library/ff402531%28v=VS.92%29.aspx#AppPlat_Overview_Arch Now it mentions everything as being in the "Cloud". Is any server just a cloud? If i have a WCF service or wsdl on my server. Can I consider myself that "Cloud"? Or is there something that a server emits that checks whether or not it is a cloud?

    Read the article

  • Updating a Cuda 4.0 project to Cuda 4.2

    - by aljndrrr
    I have a VS2010 project that was tested with CUDA 4.0, today I installed CUDA 4.2 and I want to update this project, the problem is that when I try to run the project it asks me for cudart32_40_17.dll, but since this is CUDA 4.2 I only have on my folders (C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v4.2\bin) cudart32_42_9.dll. I already set the Build Customizations to Cuda 4.2 and it compiles without any problem, the only problem is when I try to run it, the app asks me for the previous version of the dll. Is there a way to especify that the project must use cudart32_42_9.dll?

    Read the article

  • Why isn't pyinstaller making me an .exe file?

    - by Matt Miller
    I am attempting to follow this guide to make a simple Hello World script into an .exe file. I have Windows Vista with an AMD 64-bit processor I have installed Python 2.6.5 (Windows AMD64 version) I have set the PATH (if that's the right word) so that the command line recognizes Python I have installed UPX (there only seems to be a 32-bit version for Windows) and pasted a copy of upx.exe into the Python26 folder as instructed. I have installed Pywin (Windows AMD 64 Python 2.6 version) I have run Pyinstaller's Configure.py. It gives some error messages but seems to complete. I don't know if this is what's causing the problem, so the following is what it says when I run it: C:\Python26\Pyinstaller\branches\py26winConfigure.py I: read old config from C:\Python26\Pyinstaller\branches\py26win\config.dat I: computing EXE_dependencies I: Finding TCL/TK... I: Analyzing C:\Python26\DLLs_tkinter.pyd W: Cannot get binary dependencies for file: W: C:\Python26\DLLs_tkinter.pyd W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Python26\DLLs_ctypes.pyd W: Cannot get binary dependencies for file: W: C:\Python26\DLLs_ctypes.pyd W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Python26\DLLs\select.pyd W: Cannot get binary dependencies for file: W: C:\Python26\DLLs\select.pyd W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Python26\DLLs\unicodedata.pyd W: Cannot get binary dependencies for file: W: C:\Python26\DLLs\unicodedata.pyd W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Python26\DLLs\bz2.pyd W: Cannot get binary dependencies for file: W: C:\Python26\DLLs\bz2.pyd W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Python26\python.exe I: Dependent assemblies of C:\Python26\python.exe: I: amd64_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.21022.8_none I: Searching for assembly amd64_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.21022.8_ none... I: Found manifest C:\Windows\WinSxS\Manifests\amd64_microsoft.vc90.crt_1fc8b3b9a 1e18e3b_9.0.21022.8_none_750b37ff97f4f68b.manifest I: Searching for file msvcr90.dll I: Found file C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.21 022.8_none_750b37ff97f4f68b\msvcr90.dll I: Searching for file msvcp90.dll I: Found file C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.21 022.8_none_750b37ff97f4f68b\msvcp90.dll I: Searching for file msvcm90.dll I: Found file C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.21 022.8_none_750b37ff97f4f68b\msvcm90.dll I: Adding Microsoft.VC90.CRT\Microsoft.VC90.CRT.manifest I: Adding Microsoft.VC90.CRT\msvcr90.dll I: Adding Microsoft.VC90.CRT\msvcp90.dll I: Adding Microsoft.VC90.CRT\msvcm90.dll W: Cannot get binary dependencies for file: W: C:\Python26\python.exe W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Windows\WinSxS\Manifests\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e 3b_9.0.21022.8_none_750b37ff97f4f68b.manifest I: Analyzing C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.210 22.8_none_750b37ff97f4f68b\msvcr90.dll W: Cannot get binary dependencies for file: W: C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.21022.8_none_ 750b37ff97f4f68b\msvcr90.dll W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.210 22.8_none_750b37ff97f4f68b\msvcp90.dll W: Cannot get binary dependencies for file: W: C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.21022.8_none_ 750b37ff97f4f68b\msvcp90.dll W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: Analyzing C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.210 22.8_none_750b37ff97f4f68b\msvcm90.dll W: Cannot get binary dependencies for file: W: C:\Windows\WinSxS\amd64_microsoft.vc90.crt_1fc8b3b9a1e18e3b_9.0.21022.8_none_ 750b37ff97f4f68b\msvcm90.dll W: Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 608, in get Imports return _getImports_pe(pth) File "C:\Python26\Pyinstaller\branches\py26win\bindepend.py", line 275, in _ge tImports_pe importva, importsz = datadirs[1] IndexError: list index out of range I: could not find TCL/TK I: testing for Zlib... I: ... Zlib available I: Testing for ability to set icons, version resources... I: ... resource update available I: Testing for Unicode support... I: ... Unicode available I: testing for UPX... I: ...UPX available I: computing PYZ dependencies... I: done generating C:\Python26\Pyinstaller\branches\py26win\config.dat My Python script (named Hello.py) is the same as the example: #!/usr/bin/env python for i in xrange(10000): print "Hello, World!" This is my BAT file, in the same directory: set PIP=C:\Python26\Pyinstaller\branches\py26win\ python %PIP%Makespec.py --onefile --console --upx --tk Hello.py python %PIP%Build.py Hello.spec When I run Hello.bat in the command prompt several files are made, none of which are an .exe file, and the following is displayed: C:\My Filesset PIP=C:\Python26\Pyinstaller\branches\py26win\ C:\My Filespython C:\Python26\Pyinstaller\branches\py26win\Makespec.py --onefil e --console --upx --tk Hello.py wrote C:\My Files\Hello.spec now run Build.py to build the executable C:\My Filespython C:\Python26\Pyinstaller\branches\py26win\Build.py Hello.spec I: Dependent assemblies of C:\Python26\python.exe: I: amd64_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.21022.8_none Traceback (most recent call last): File "C:\Python26\Pyinstaller\branches\py26win\Build.py", line 1359, in main(args[0], configfilename=opts.configfile) File "C:\Python26\Pyinstaller\branches\py26win\Build.py", line 1337, in main build(specfile) File "C:\Python26\Pyinstaller\branches\py26win\Build.py", line 1297, in build execfile(spec) File "Hello.spec", line 3, in pathex=['C:\My Files']) File "C:\Python26\Pyinstaller\branches\py26win\Build.py", line 292, in _init _ raise ValueError, "script '%s' not found" % script ValueError: script 'C:\Python26\Pyinstaller\branches\py26win\support\useTK.py' n ot found I have limited knowledge with the command prompt, so please take baby steps with me if I need to do something there.

    Read the article

  • Extrapolation using fft in octave

    - by CFP
    Using GNU octave, I'm computing a fft over a piece of signal, then eliminating some frequencies, and finally reconstructing the signal. This give me a nice approximation of the signal ; but it doesn't give me a way to extrapolate the data. Suppose basically that I have plotted three periods and a half of f: x -> sin(x) + 0.5*sin(3*x) + 1.2*sin(5*x) and then added a piece of low amplitude, zero-centered random noise. With fft/ifft, I can easily remove most of the noise ; but then how do I extrapolate 3 more periods of my signal data? (other of course that duplicating the signal). The math way is easy : you have a decomposition of your function as an infinite sum of sines/cosines, and you just need to extract a partial sum and apply it anywhere. But I don't quite get the programmatic way... Thanks!

    Read the article

  • chomsky hierarchy and programming languages

    - by dader51
    Hi, I'm trying to learn some aspects of the CH ( chomsky hierarchy ) which are related to PL ( programming languages ), and i still have to read the Dragon Book. I've read that most of the PL can be parsed as CFG ( context free grammar ). In term of computational power, it equals the one of a pushdown non deterministic automaton. Am I right ? If it's true, then how could a CFG holds a UG ( unrestricted grammar, which is turing complete ) ? I'm asking because, even if PL are CFG they are actually used to describe TM (turing machines ) and through UG. I think that's because of at least two different levels of computing, the first, which is the parsing of a CFG focuses on the syntax related to the structure ( representation ? ) of the language, while the other focuses on the semantic ( sense, interpretation of the data itself ? ) related to the capabilities of the pl which is turing complete. Again, are these assumptions rights ? thanx a lot.

    Read the article

  • GWT 2.X No resource found for key

    - by Han Fastolfe
    I've developed a GWT app using i18n internationalization. In Host/Dev mode it works fine, but launching GWT compile gives this error: No resource found for key xxx, like below. Compiling module ...rte.RTE Scanning for additional dependencies: file:/home/.../client/i18n/RTEValidationMessages.java Computing all possible rebind results for '...client.i18n.RTEMessages' Rebinding ...client.i18n.RTEMessages Invoking com.google.gwt.dev.javac.StandardGeneratorContext@e7dfd0 Processing interface ...client.i18n.RTEMessages Generating method body for txtIndirizzo3() [ERROR] No resource found for key 'txtIndirizzo3' Messages are loaded with late binding. public class RTEValidationMessages { private RTEMessages additionalMessages; public RTEValidationMessages() { additionalMessages = GWT.create(RTEMessages.class); } } Deleting the method which gives the error, results in another random method with error, say not the method before or after in the interface ...client.i18n.RTEMessages. Help is greatly appreciated.

    Read the article

  • Using ZeroC Middleware

    - by Sean
    I'm currently looking at various middleware solutions that will allow me to create applications in a variety of languages which are able to communicate amongst each other. The ZeroC product suite seems ideal as it provides a language agnostic way of defining data and the services that operate on the data (via its ICE idl) and provides support for all the mainstream languages. It also appears to offer a lot of other things we'd want, such as load balancing, grid computing and managed deployment. However, my google-fu has let me down and I'm having trouble finding information from people who have used it to implements system. I'm looking for feedback from projects that use it, and what issues/successes they had. I'm also interested in feedback from projects that evaluated it and chose not to use it (and why).

    Read the article

  • How would you go about tackling this problem?

    - by incrediman
    I have a programming contest coming up in about half a week, and I've been prepping :) I found a bunch of questions from this canadian competition, they're great practice: http://cemc.math.uwaterloo.ca/contests/computing/2009/stage2/day1.pdf I'm looking at problem B ("Dinner"). Any idea where to start? I can't really think of anything besides the naive approach (ie. trying all permutations) which would take too long to be a valid answer. Btw, the language there says c++ and pascal I think, but i don't care what language you use - I mean really all I want is a brief description of how to tackle the problem. Like "use X technique treating each programmer as a Y" or something :)

    Read the article

  • On-the-fly lossless image compression

    - by geschema
    I have an embedded application where an image scanner sends out a stream of 16-bit pixels that are later assembled to a grayscale image. As I need to both save this data locally and forward it to a network interface, I'd like to compress the data stream to reduce the required storage space and network bandwidth. Is there a simple algorithm that I can use to losslessly compress the pixel data? I first thought of computing the difference between two consecutive pixels and then encoding this difference with a Huffman code. Unfortunately, the pixels are unsigned 16-bit quantities so the difference can be anywhere in the range -65535 .. +65535 which leads to potentially huge codeword lengths. If a few really long codewords occur in a row, I'll run into buffer overflow problems.

    Read the article

  • MySQl Error #1064

    - by 01010011
    Hi, I keep getting this error: MySQL said: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INSERT INTO books.book(isbn10,isbn13,title,edition,author_f_name,author_m_na' at line 15 with this query: USE books; DROP TABLE IF EXISTS book; CREATE TABLE `books`.`book`( `book_id` INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, `isbn10` VARCHAR(15) NOT NULL, `isbn13` VARCHAR(15) NOT NULL, `title` VARCHAR(50) NOT NULL, `edition` VARCHAR(50) NOT NULL, `author_f_name` VARCHAR(50) NOT NULL, `author_m_name` VARCHAR(50) NOT NULL, `author_l_name` VARCHAR(50) NOT NULL, `cond` ENUM('as new','very good','good','fair','poor') NOT NULL, `price` DECIMAL(8,2) NOT NULL, `genre` VARCHAR(50) NOT NULL, `quantity` INT NOT NULL) INSERT INTO books.book(isbn10,isbn13,title,edition,author_f_name,author_m_name,author_l_name,cond,price,genre,quantity)** VALUES ('0136061699','978-0136061694','Software Engineering: Theory and Practice','4','Shari','Lawrence','Pfleeger','very good','50','Computing','2'); Any idea what the problem is?

    Read the article

  • [java] Efficiency of while(true) ServerSocket Listen

    - by Submerged
    I am wondering if a typical while(true) ServerSocket listen loop takes an entire core to wait and accept a client connection (Even when implementing runnable and using Thread .start()) I am implementing a type of distributed computing cluster and each computer needs every core it has for computation. A Master node needs to communicate with these computers (invoking static methods that modify the algorithm's functioning). The reason I need to use sockets is due to the cross platform / cross language capabilities. In some cases, PHP will be invoking these java static methods. I used a java profiler (YourKit) and I can see my running ServerSocket listen thread and it never sleeps and it's always running. Is there a better approach to do what I want? Or, will the performance hit be negligible? Please, feel free to offer any suggestion if you can think of a better way (I've tried RMI, but it isn't supported cross-language. Thanks everyone

    Read the article

  • Shortest-path algorithms which use a space-time tradeoff?

    - by Chris Mounce
    I need to find shortest paths in an unweighted, undirected graph. There are algorithms which can find a shortest path between two nodes, but this can take time. There are also algorithms for computing shortest paths for all pairs of nodes in the graph, but storing such a lookup table would take lots of disk space. What I'm wondering: Is there an algorithm which offers a space-time tradeoff that's somewhere between these two extremes? In other words, is there a way to speed up a shortest-path search, while using less disk space than would be occupied by an all-pairs shortest-path table? I know there are ways to efficiently store lookup tables for this problem, and I already have a couple of ideas for speeding up shortest-path searches using precomputed data. But I don't want to reinvent the wheel if there's already some established algorithm that solves this problem.

    Read the article

  • Complex behavior generated by simple computation

    - by Yuval A
    Stephen Wolfram gave a fascinating talk at TED about his work with Mathematica and Wolfram Alpha. Amongst other things, he pointed out how very simple computations can yield extremely complex behaviors. (He goes on to discuss his ambition for computing the entire physical universe. Say what you will, you gotta give the guy some credit for his wild ideas...) As an example he showed several cellular automata. What other examples of simple computations do you know of that yield fascinating results?

    Read the article

  • Entry Level Programming Jobs with Applied Math Degree

    - by Mark
    I am about to finish my B.Sc. in Applied Math. I started out in CS a few years back had a bit of a change of heart and decided to go the math route. Now that I am looking for career options finishing up and I'm just wonder how my Applied Math degree will look when applying for programming jobs. I have taken CS courses in C++/Java/C and done 2 semester of Scientific Computing with MATLAB/Mathematica and the like, so I feel like i at least know how to program. Of course I am lacking some of the theoretical courses on the CS. I'd very much like to know how I stack up for a programming job as a math major. Thanks.

    Read the article

  • NFS Server in Java

    - by dmeister
    I search an implementation of a network (or distributed) file system like NFS in Java. The goal is to extend it and do some research stuff with it. On the web I found some implementation e.g. DJ NFS, but the open question is how mature and fast they are. Can anyone purpose a good starting point, has anyone experience with such things? P.S. I know Hadoop DFS and I used it for some projects, but Hadoop is not a good fit for the things I want to do here. --EDIT-- Hadoop is really focused on highly scalable, high throughput computing without the possibilities to overwrite parts of a file and so an. The goal is you could use the filesystem e.g. for user home directories. --EDIT-- More Details: The idea is to modify such a implementation so that the files are not stored directly on a local filesystem, but to apply data de-duplication.

    Read the article

  • Best language to learn complementing java

    - by danielrutledge
    Hi all, I'm a somewhat experienced java ee developer, and I wish to complement my background by learning a newish language. I'm recently out of school where I did a ton of scientific computing and some functional programming, so I'm pretty comfortable with those families of languages. If at all possible, I'd like to pick a language with some market value, though I know this is tough to gauge. After snooping around a bit, the consensus seems to be one of Python/Ruby/Perl; how would each of these work with java in a web application environment, and in your opinion which complements it best? Any other suggestions for languages would also be welcome.

    Read the article

  • How do I give MacPorts privileges?

    - by cojadate
    I tried to install PostgreSQL server development libraries using MacPorts and got the following: Warning: MacPorts running without privileges. You may be unable to complete certain actions (e.g. install). ---> Computing dependencies for postgresql-server-devel ---> Dependencies to be installed: postgresql-devel ---> Building postgresql-devel Error: Target org.macports.build returned: shell command failed Error: The following dependencies failed to build: postgresql-devel Error: Status 1 encountered during processing. To report a bug, see <http://guide.macports.org/#project.tickets> So I guess that means I need to running MacPorts with privileges and try again. Unfortunately I've no idea how to give MacPorts privileges. I'm running OS X 10.6.3

    Read the article

  • Precompile Lambda Expression Tree conversions as constants?

    - by Nathan
    It is fairly common to take an Expression tree, and convert it to some other form, such as a string representation (for example this question and this question, and I suspect Linq2Sql does something similar). In many cases, perhaps even most cases, the Expression tree conversion will always be the same, i.e. if I have a function public string GenerateSomeSql(Expression<Func<TResult, TProperty>> expression) then any call with the same argument will always return the same result for example: GenerateSomeSql(x => x.Age) //suppose this will always return "select Age from Person" GenerateSomeSql(x => x.Ssn) //suppose this will always return "select Ssn from Person" So, in essence, the function call with a particular argument is really just a constant, except time is wasted at runtime re-computing it continuously. Assuming, for the sake of argument, that the conversion was sufficiently complex to cause a noticeable performance hit, is there any way to pre-compile the function call into an actual constant?

    Read the article

  • Formatting a barcode with hyphens in between - Assignment question

    - by capex
    Hi, The assignment at my first year uni computing course says my program should read a barcode number, and then display the same 13 digit barcode number separated by hyphens. For example, 9300675016902 should look like 930-067501-690-1. The restrictions say I can't use the following: No arrays No strings No functions. Any directions on this? (So far I have done this: part1 = barcode/10000000000; which gives me the first three digits, and this: part4 = barcode%10; which gives me the last digit. Thanks in advance!

    Read the article

  • Sum of path products in DAG

    - by Jules
    Suppose we have a DAG with edges labeled with numbers. Define the value of a path as the product of the labels. For each (source,sink)-pair I want to find the sum of the values of all the paths from source to sink. You can do this in polynomial time with dynamic programming, but there are still some choices that can be made in how you decompose the problem. In my case I have one DAG that has to be evaluated repeatedly with different labelings. My question is: for a given DAG, how can we pre-compute a good strategy for computing these values for different labelings repeatedly. It would be nice if there was an algorithm that finds an optimal way, for example a way that minimizes the number of multiplications. But perhaps this is too much to ask, I would be very happy with an algorithm that just gives a good decomposition.

    Read the article

< Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >