Search Results

Search found 5688 results on 228 pages for 'newbie programmer'.

Page 216/228 | < Previous Page | 212 213 214 215 216 217 218 219 220 221 222 223  | Next Page >

  • NHibernate Tutorial Run-Time Error: HibernateException

    - by Kashif
    I'm a newbie at NHibernate so please go easy on me if I have asked a stupid question... I am following the tutorial for NHibernate posted here and am getting a run-time error of type "HibernateException" The code in question looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Text; using FirstSolution; using NHibernate.Cfg; using NHibernate.Tool.hbm2ddl; using NUnit.Framework; namespace FirstSolution.Tests { [TestFixture] public class GenerateSchema_Fixture { [Test] public void Can_generate_schema() { var cfg = new Configuration(); cfg.Configure(); cfg.AddAssembly(typeof(Product).Assembly); new SchemaExport(cfg).Execute(false, true, false); } } } The line I am getting the error at is: cfg.AddAssembly(typeof(Product).Assembly); The inner-most exception is: The IDbCommand and IDbConnection implementation in the assembly System.Data.SqlServerCe could not be found And here's my stack trace: at NHibernate.Connection.ConnectionProvider.ConfigureDriver(IDictionary`2 settings) at NHibernate.Connection.ConnectionProvider.Configure(IDictionary`2 settings) at NHibernate.Connection.ConnectionProviderFactory.NewConnectionProvider(IDictionary`2 settings) at NHibernate.Tool.hbm2ddl.SchemaExport.Execute(Action`1 scriptAction, Boolean export, Boolean justDrop) at NHibernate.Tool.hbm2ddl.SchemaExport.Execute(Boolean script, Boolean export, Boolean justDrop) at FirstSolution.Tests.GenerateSchema_Fixture.Can_generate_schema() in C:\Users\Kash\Documents\Visual Studio 2010\Projects\FirstSolution\FirstSolution\GenerateSchema_Fixture.cs:line 23 at HibernateUnitTest.Form1.button1_Click(Object sender, EventArgs e) in C:\Users\Kash\Documents\Visual Studio 2010\Projects\FirstSolution\HibernateUnitTest\Form1.cs:line 23 at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(Form mainForm) at HibernateUnitTest.Program.Main() in C:\Users\Kash\Documents\Visual Studio 2010\Projects\FirstSolution\HibernateUnitTest\Program.cs:line 18 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() I've made sure that System.Data.SqlServerCe has been referenced and that its Copy Local property is set to True. The error persists, however. Your help would be appreciated. Thanks.

    Read the article

  • Advice for Architecture Design Logic for software application

    - by Prasad
    Hi, I have a framework of basic to complex set of objects/classes (C++) running into around 500. With some rules and regulations - all these objects can communicate with each other and hence can cover most of the common queries in the domain. My Dream: I want to provide these objects as icons/glyphs (as I learnt recently) on a workspace. All these objects can be dragged/dropped into the workspace. They have to communicate only through their methods(interface) and in addition to few iterative and conditional statements. All these objects are arranged finally to execute a protocol/workflow/dataflow/process. After drawing the flow, the user clicks the Execute/run button. All the user interaction should be multi-touch enabled. The best way to show my dream is : Jeff Han's Multitouch Video. consider Jeff is playing with my objects instead of the google maps. :-) it should be like playing a jigsaw puzzle. Objective: how can I achieve the following while working on this final product: a) the development should be flexible to enable provision for web services b) the development should enable easy web application development c) The development should enable client-server architecture - d) further it should also enable mouse based drag/drop desktop application like Adobe programs etc. I mean to say: I want to economize on investments. Now I list my efforts till now in design : a) Created an Editor (VB) where the user writes (manually) the object / class code b) On Run/Execute, the code is copied into a main() function and passed to interpreter. c) Catch the output and show it in the console. The interpreter can be separated to become a server and the Editor can become the client. This needs lot of standard client-server architecture work. But some how I am not comfortable in the tightness of this system. Without interpreter is there much faster and better embeddable solution to this? - other than writing a special compiler for these objects. Recently learned about AXIS-C++ can help me - looks like - a friend suggested. Is that the way to go ? Here are my questions: (pl. consider me a self taught programmer and NOT my domain) a) From the stage of C++ objects to multi-touch product, how can I make sure I will develop the parallel product/service models as well.? What should be architecture aspects I should consider ? b) What technologies are best suited for this? c) If I am thinking of moving to Cloud Computing, how difficult/ how redundant / how unnecessary my efforts will be ? d) How much time in months would it take to get the first beta ? I take the liberty to ask if any of the experts here are interested in this project, please email me: [email protected] Thank you for any help. Looking forward.

    Read the article

  • Boggling Direct3D9 dynamic vertex buffer Lock crash/post-lock failure on Intel GMA X3100.

    - by nj
    Hi, For starters I'm a fairly seasoned graphics programmer but as wel all know, everyone makes mistakes. Unfortunately the codebase is a bit too large to start throwing sensible snippets here and re-creating the whole situation in an isolated CPP/codebase is too tall an order -- for which I am sorry, do not have the time. I'll do my best to explain. B.t.w, I will of course supply specific pieces of code if someone wonders how I'm handling this-or-that! As with all resources in the D3DPOOL_DEFAULT pool, when the device context is taken away from you you'll sooner or later will have to reset your resources. I've built a mechanism to handle this for all relevant resources that's been working for years; but that fact nothingwithstanding I've of course checked, asserted and doubted any assumption since this bug came to light. What happens is as follows: I have a rather large dynamic vertex buffer, exact size 18874368 bytes. This buffer is locked (and discarded fully using the D3DLOCK_DISCARD flag) each frame prior to generating dynamic geometry (isosurface-related, f.y.i) to it. This works fine, until, of course, I start to reset. It might take 1 time, it might take 2 or it might take 5 resets to set off a bug that causes an access violation either on the pointer returned by the Lock() operation on the renewed resource or a plain crash -- regarding a somewhat similar address, but without the offset that it has tacked on to it in the first case because in that case we're somewhere halfway writing -- iside the D3D9 dll Lock() call. I've tested this on other hardware, upgraded my GMA X3100 drivers (using a MacBook with BootCamp) to the latest ones, but I can't reproduce it on any other machine and I'm at a loss about what's wrong here. I have tried to reproduce a similar situation with a similar buffer (I've got a large scratch pad of the same type I filled with quads) and beyond a certain amount of bytes it started to behave likewise. I'm not asking for a solution here but I'm very interested if there are other developers here who have battled with the same foe or maybe some who can point me in some insightful direction, maybe ask some questions that might shed a light on what I may or may not be overlooking. Another interesting artifact is that the vertex buffer starts to bug if I supply both D3DLOCK_DISCARD and D3DLOCK_NOOVERWRITE together which, even though not very logical (you're not going to overwrite if you've just discarded all), gives graphics glitches. Thanks and any corrections are more than welcome. Niels p.s - A friend of mine raised the valid point that it is a huge buffer for onboard video RAM and it's being at least double or triple buffered internally due to it's dynamic nature. On the other hand, the debug output (D3D9 debug DLL + max. warning output) remains silent. p.s 2 - Had it tested on more machines and still works -- it's probably a matter of circumstance: the huge dynamic, internally double/trippled buffered buffer, not a lot of memory and drivers that don't complain when they should.. Unless someone has a better suggestion; I'd still love to hear it :)

    Read the article

  • SimpleXML SOAP response Namespace issues

    - by Stu
    Hi. After spending SEVERAL frustrated hours on this I am asking for your help. I am trying to get the content of particular nodes from a SOAP response. The response is $XmlStr = <?xml version="1.0" encoding="UTF-8"?><env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope"<xmlns:ns1="http://soap.xxxxxx.co.uk/"><env:Body><ns1:PlaceOrderResponse><xxxxxOrderNumber></xxxxxOrderNumber><ErrorArray><Error><ErrorCode>24</ErrorCode><ErrorText>The+client+order+number+3002254+is+already+in+use</ErrorText></Error><Error><ErrorCode>1</ErrorCode><ErrorText>Aborting</ErrorText></Error></ErrorArray></ns1:PlaceOrderResponse></env:Body></env:Envelope> I am trying to get at the nodes and children of <ErrorArray. Because of the XML containing namespaces $XmlArray = new SimpleXMLElement($XmlStr); foreach ($XmlArray->env:Envelope->env:Body->ns1:PlaceOrderResponse->ErrorArray->Error as $Error) { echo $Error->ErrorCode."<br />";<br /> } doesn't work. I have read a number of articles such as http://www.sitepoint.com/blogs/2005/10/20/simplexml-and-namespaces/ htp://blog.stuartherbert.com/php/2007/01/07/using-simplexml-to-parse-rss-feeds/ and about 20 questions on this site which unfortunately are not helping. (the second link has htp:// as a newbie here I cannot post more than one link) Even writing, $XmlArray = new SimpleXMLElement($XmlStr); echo "<br /><br /><pre>\n"; print_r($XmlArray); echo "<pre><br /><br />\n"; gives SimpleXMLElement Object ( ) which makes me wonder if the soap response ($XmlStr) is actually a valid input for SimpleXMLElement. It seems that the line $XmlArray = new SimpleXMLElement($XmlStr); is not doing what I expect it to. Any help on how to get the nodes from the XML above would be very welcome. Obviously getting it to work (having a working example) is what I need in the short term, but if someone could help me understand what I am doing wrong would be better in the long term. Cheers. Stu

    Read the article

  • ASP NET MVC (loading data from database)

    - by rah.deex
    hi experts, its me again... i have some code like this.. using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace MvcGridSample.Models { public class CustomerService { private List<SVC> Customers { get { List<SVC> customers; if (HttpContext.Current.Session["Customers"] != null) { customers = (List<SVC>) HttpContext.Current.Session["Customers"]; } else { //Create customer data store and save in session customers = new List<SVC>(); InitCustomerData(customers); HttpContext.Current.Session["Customers"] = customers; } return customers; } } public SVC GetByID(int customerID) { return this.Customers.AsQueryable().First(customer => customer.seq_ == customerID); } public IQueryable<SVC> GetQueryable() { return this.Customers.AsQueryable(); } public void Add(SVC customer) { this.Customers.Add(customer); } public void Update(SVC customer) { } public void Delete(int customerID) { this.Customers.RemoveAll(customer => customer.seq_ == customerID); } private void InitCustomerData(List<SVC> customers) { customers.Add(new SVC { ID = 1, FirstName = "John", LastName = "Doe", Phone = "1111111111", Email = "[email protected]", OrdersPlaced = 5, DateOfLastOrder = DateTime.Parse("5/3/2007") }); customers.Add(new SVC { ID = 2, FirstName = "Jane", LastName = "Doe", Phone = "2222222222", Email = "[email protected]", OrdersPlaced = 3, DateOfLastOrder = DateTime.Parse("4/5/2008") }); customers.Add(new SVC { ID = 3, FirstName = "John", LastName = "Smith", Phone = "3333333333", Email = "[email protected]", OrdersPlaced = 25, DateOfLastOrder = DateTime.Parse("4/5/2000") }); customers.Add(new SVC { ID = 4, FirstName = "Eddie", LastName = "Murphy", Phone = "4444444444", Email = "[email protected]", OrdersPlaced = 1, DateOfLastOrder = DateTime.Parse("4/5/2003") }); customers.Add(new SVC { ID = 5, FirstName = "Ziggie", LastName = "Ziggler", Phone = null, Email = "[email protected]", OrdersPlaced = 0, DateOfLastOrder = null }); customers.Add(new SVC { ID = 6, FirstName = "Michael", LastName = "J", Phone = "666666666", Email = "[email protected]", OrdersPlaced = 5, DateOfLastOrder = DateTime.Parse("12/3/2007") }); } } } those codes is an example that i've got from the internet.. in that case, the data is created and saved in session before its shown.. the things that i want to ask is how if i want to load the data from table? i'am a newbie here.. please help :) thank b4 for advance..

    Read the article

  • error C2065: 'CComQIPtr' : undeclared identifier

    - by Ken Smith
    I'm still feeling my way around C++, and am a complete ATL newbie, so I apologize if this is a basic question. I'm starting with an existing VC++ executable project that has functionality I'd like to expose as an ActiveX object (while sharing as much of the source as possible between the two projects). I've approached this by adding an ATL project to the solution in question, and in that project have referenced all the .h and .cpp files from the executable project, added all the appropriate references, and defined all the preprocessor macros. So far so good. But I'm getting a compiler error in one file (HideDesktop.cpp). The relevant parts look like this: #include "stdafx.h" #define WIN32_LEAN_AND_MEAN #include <Windows.h> #include <WinInet.h> // Shell object uses INTERNET_MAX_URL_LENGTH (go figure) #if _MSC_VER < 1400 #define _WIN32_IE 0x0400 #endif #include <atlbase.h> // ATL smart pointers #include <shlguid.h> // shell GUIDs #include <shlobj.h> // IActiveDesktop #include "stdhdrs.h" struct __declspec(uuid("F490EB00-1240-11D1-9888-006097DEACF9")) IActiveDesktop; #define PACKVERSION(major,minor) MAKELONG(minor,major) static HRESULT EnableActiveDesktop(bool enable) { CoInitialize(NULL); HRESULT hr; CComQIPtr<IActiveDesktop, &IID_IActiveDesktop> pIActiveDesktop; // <- Problematic line (throws errors 2065 and 2275) hr = pIActiveDesktop.CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER); if (!SUCCEEDED(hr)) { return hr; } COMPONENTSOPT opt; opt.dwSize = sizeof(opt); opt.fActiveDesktop = opt.fEnableComponents = enable; hr = pIActiveDesktop->SetDesktopItemOptions(&opt, 0); if (!SUCCEEDED(hr)) { CoUninitialize(); // pIActiveDesktop->Release(); return hr; } hr = pIActiveDesktop->ApplyChanges(AD_APPLY_REFRESH); CoUninitialize(); // pIActiveDesktop->Release(); return hr; } This code is throwing the following compiler errors: error C2065: 'CComQIPtr' : undeclared identifier error C2275: 'IActiveDesktop' : illegal use of this type as an expression error C2065: 'pIActiveDesktop' : undeclared identifier The two weird bits: (1) CComQIPtr is defined in atlcomcli.h, which is included in atlbase.h, which is included in HideDesktop.cpp; and (2) this file is only throwing these errors when it's referenced in my new ATL/AX project: it's not throwing them in the original executable project, even though they have basically the same preprocessor definitions. (The ATL AX project, naturally enough, defines _ATL_DLL, but I can't see where that would make a difference.) My current workaround is to use a normal "dumb" pointer, like so: IActiveDesktop *pIActiveDesktop; HRESULT hr = ::CoCreateInstance(CLSID_ActiveDesktop, NULL, // no outer unknown CLSCTX_INPROC_SERVER, IID_IActiveDesktop, (void**)&pIActiveDesktop); And that works, provided I remember to release it. But I'd rather be using the ATL smart stuff. Any thoughts?

    Read the article

  • random, Graphics point ,searching- algorithm, via dual for loop set

    - by LoneXcoder
    hello and thanks for joining me in my journey to the custom made algorithm for "guess where the pixel is" this for Loop set (over Point.X, Point.Y), is formed in consecutive/linear form: //Original\initial Location Point initPoint = new Point(150, 100); // No' of pixels to search left off X , and above Y int preXsrchDepth, preYsrchDepth; // No' of pixels to search to the right of X, And Above Y int postXsrchDepth, postYsrchDepth; preXsrchDepth = 10; // will start search at 10 pixels to the left from original X preYsrchDepth = 10; // will start search at 10 pixels above the original Y postXsrchDepth = 10; // will stop search at 10 pixels to the right from X postYsrchDepth = 10; // will stop search at 10 pixels below Y int StopXsearch = initPoint.X + postXsrchDepth; //stops X Loop itarations at initial pointX + depth requested to serch right of it int StopYsearch = initPoint.Y + postYsrchDepth; //stops Y Loop itarations at initial pointY + depth requested below original location int CountDownX, CountDownY; // Optional not requierd for loop but will reports the count down how many iterations left (unless break; triggerd ..uppon success) Point SearchFromPoint = Point.Empty; //the point will be used for (int StartX = initPoint.X - preXsrchDepth; StartX < StopXsearch; StartX++) { SearchFromPoint.X = StartX; for (int StartY = initPoint.Y - preYsrchDepth; StartY < StpY; StartY++) { CountDownX = (initPoint.X - StartX); CountDownY=(initPoint.Y - StartY); SearchFromPoint.Y = StartY; if (SearchSuccess) { same = true; AAdToAppLog("Search Report For: " + imgName + "Search Completed Successfully On Try " + CountDownX + ":" + CountDownY); break; } } } <-10 ---- -5--- -1 X +1--- +5---- +10 what i would like to do is try a way of instead is have a little more clever approach <+8---+5-- -8 -5 -- +2 +10 X -2 - -10 -8-- -6 ---1- -3 | +8 | -10 Y +1 -6 | | +9 .... I do know there's a wheel already invented in this field (even a full-trailer truck amount of wheels (: ) but as a new programmer, I really wanted to start of with a simple way and also related to my field of interest in my project. can anybody show an idea of his, he learnt along the way to Professionalism in algorithm /programming having tests to do on few approaches (kind'a random cleverness...) will absolutely make the day and perhaps help some others viewing this page in the future to come it will be much easier for me to understand if you could use as much as possible similar naming to variables i used or implenet your code example ...it will be Greatly appreciated if used with my code sample, unless my metod is a realy flavorless. p.s i think that(atleast as human being) the tricky part is when throwing inconsecutive numbers you loose track of what you didn't yet use, how do u take care of this too . thanks allot in advance looking forward to your participation !

    Read the article

  • Do you feel underappreciated or resent the geek/nerd stigma?

    - by dotnetdev
    At work we have a piece of A4 paper with the number of everyone in the office. The structure of this document is laid out in rectangles, by department. I work for the department that does all the technical stuff. That includes support—bear in mind that the support staff isn't educated in IT but just has experience in PC maintenance and providing support to a system we resell but don't have source code access to, project manager, team leader, a network administrator, a product manager, and me, a programmer. Anyway, on this paper, we are labelled as nerds and geeks. I did take a little offence to this, as much as it is light hearted (but annoying and old) humour. I have a vivid image that a geek is someone who doesn't go out but codes all day. I code all day at home and at work (when I have something to code...), but I keep balance by going out. I don't know why it is only people who work with computers that get such a stigma. No other profession really gets the same stigma—skilled, technical, or whatever. An account manager (and this is hardly a skilled job) says, "Perhaps [MY NAME HERE] could write some geeky code tomorrow to add this functionality to the website." It is funny how I get such an unfair stigma but I am so pivotal. In fact, if it wasn't for me, the company would have nothing to sell so the account managers would be redundant! I make systems, they get sold, and this is what pays the wages. It's funny how the account managers get a commission for how many systems they sell, or manage to make clients resubscribe to. Yet I built the thing in the first place! On top of that, my brother says all I do is type stuff on a keyboard all day. Surely if I did, I'd be typing at my normal typing speed of 100wpm+ as if I am writing a blog entry. Instead, I plan as I code along on the fly if commercial pressures and time prohibit proper planning. I never type as if I'm writing normal English. There is more to our jobs than just typing code. And my brother is a pipe fitter with no formal qualifications in his name. I could easily, and perhaps more justifiably, say he just manipulates a spanner or something. Does you feel underappreciated or that a geek/nerd stigma is undeserved or unfair?

    Read the article

  • How to call Ajax to run a PHP file while maintaining PHP & Javascript variables.

    - by Umar
    Hi Stackoverflowers. I'm using the Facebook php-sdk to get the users name and friends, right now the loading friends part takes about +3 seconds so I wanted to do it via Ajax, e.g. so the document can load and jQuery then calls an external PHP script which loads the friends (their names and their profile pictures). So to do this I did: $(document).ready(function() { var loadUrl = "http://localhost/fb/getFriends.php" ; $("#friends") .html("Hold on, your friends are loading!") .load(loadUrl); }); But I get a PHP error: Fatal error: Call to a member function api() on a non-object If I do this in the same PHP file (so I don't use Ajax at all to call it) it works fine. Now I think I understand the reason this is happening, but I don't know how to fix it. In my main index.php file I have a bunch of init and session code e.g. FB.init({ appId : '<?php echo $facebook->getAppId(); ?>', session : <?php echo json_encode($session); ?>, // don't refetch the session when PHP already has it status : true, // check login status cookie : true, // enable cookies to allow the server to access the session xfbml : true // parse XFBML }); So I'm just wondering what is the best way to treat my new separate PHP file getFriends.php in a way where it has access to all PHP/JavaScript session data/variables? If you haven't used the Facebook php-sdk I'll quickly explain what I mean: Lets say I have index.php and getUsername.php, from index.php I want to retrieve the getUsername.php file via Ajax using .load. Now the problem is getUsername.php needs to access PHP session data/Javascript Init functions which were created in index.php, so I'm thinking of ways to solve this (I'm new to PHP so sorry if this sounds silly) but I'm thinking maybe I could do a POST in jQuery Ajax and post the session data? Or maybe I could create a PHP class, so something like: class getUsername extends index{} /*Yes I'm a newbie*/ If you have a look at the php-sdk example.php link posted at the top maybe you'd better understand what variables exactly need to be accessed from a new file. Also on a different note, I'm using PHP to work out page rendering times and it seems that fetching the users name alone : // Session based API call. if ($session) { try { $uid = $facebook->getUser(); $me = $facebook->api('/me'); } catch (FacebookApiException $e) { error_log($e); } } Can take a good 4 seconds, is this normal? Once I get the users details is it good to cache it or something? -Speed isn't as important right now, for now I'm just trying to figure out this Ajax-separating php files thing. Woah this is a long post. Thanks very much for your time.

    Read the article

  • Performance Optimization for Matrix Rotation

    - by Summer_More_More_Tea
    Hello everyone: I'm now trapped by a performance optimization lab in the book "Computer System from a Programmer's Perspective" described as following: In a N*N matrix M, where N is multiple of 32, the rotate operation can be represented as: Transpose: interchange elements M(i,j) and M(j,i) Exchange rows: Row i is exchanged with row N-1-i A example for matrix rotation(N is 3 instead of 32 for simplicity): ------- ------- |1|2|3| |3|6|9| ------- ------- |4|5|6| after rotate is |2|5|8| ------- ------- |7|8|9| |1|4|7| ------- ------- A naive implementation is: #define RIDX(i,j,n) ((i)*(n)+(j)) void naive_rotate(int dim, pixel *src, pixel *dst) { int i, j; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) dst[RIDX(dim-1-j, i, dim)] = src[RIDX(i, j, dim)]; } I come up with an idea by inner-loop-unroll. The result is: Code Version Speed Up original 1x unrolled by 2 1.33x unrolled by 4 1.33x unrolled by 8 1.55x unrolled by 16 1.67x unrolled by 32 1.61x I also get a code snippet from pastebin.com that seems can solve this problem: void rotate(int dim, pixel *src, pixel *dst) { int stride = 32; int count = dim >> 5; src += dim - 1; int a1 = count; do { int a2 = dim; do { int a3 = stride; do { *dst++ = *src; src += dim; } while(--a3); src -= dim * stride + 1; dst += dim - stride; } while(--a2); src += dim * (stride + 1); dst -= dim * dim - stride; } while(--a1); } After carefully read the code, I think main idea of this solution is treat 32 rows as a data zone, and perform the rotating operation respectively. Speed up of this version is 1.85x, overwhelming all the loop-unroll version. Here are the questions: In the inner-loop-unroll version, why does increment slow down if the unrolling factor increase, especially change the unrolling factor from 8 to 16, which does not effect the same when switch from 4 to 8? Does the result have some relationship with depth of the CPU pipeline? If the answer is yes, could the degrade of increment reflect pipeline length? What is the probable reason for the optimization of data-zone version? It seems that there is no too much essential difference from the original naive version. EDIT: My test environment is Intel Centrino Duo processor and the verion of gcc is 4.4 Any advice will be highly appreciated! Kind regards!

    Read the article

  • Good working habits to observe in project development?

    - by Will Marcouiller
    As my development experience grows, I see fit to stick to best practices from here and there to build somehow my own working practices while observing the conventions, etc. I'm currently working on a project which my goals is to graduate the security access model from an environment's Active Directory to another environment's automatically. I don't know for any of you, but as far as I'm concerned, I meet some real difficulties sticking to only one way, then develop. I mean, I learn something new everyday while visiting SO, and recently wanted to get acquainted with generics. On the other hand, I better know the Façade pattern which proved to be very practical in transactional programming in process systems. This seems to be less practical for desktop application as there are plenty of variables to consider in a desktop application that you don't have to care in transactional programming, as you're playing only with information data. As for my current project, I have: Groups; Organizational Units; Users. Which are all considered an entry in the Active Directory. This points out to be a good candidate for generics, as also approached this way by Bart de Smett's Linq to AD on CodePlex. He has a DirectorySource<T>, and to manage let's say groups, then he instantiate a source with the proper type: var groups = new DirectorySource<Group>(); This seems to be very a good way of doing. Despite, I seem to go from one pattern to another and I don't seem to be able to strictly stick to one. While I'm aware that one must not stay with only one way of doing, since each pattern statisfies certain advantages, while also illustrating disadvantages under some usage conditions, I seem to want to develop with both patterns having a singleton Façade class with the underlying factories which represent the sub systems: GroupsFactory; UsersFactory; OrganizationalUnitsFactory. Each of the factories offers the possible operations for their respective entity (group, user, OU). To make a very long story short, I often have plenty of ideas while developping and this causes me some trouble, as I go from an idea to another feeling completely lost after a while. Yet I understand the advantages and disavantages, I have no trouble choosing from one pattern to another depending on the situation. Nevertheless, when it comes to programming itself, if I'm not part of a team, I feel sometimes like I can't do anything good. That is, because I can't stand not doing something "perfect" the first time. The role I play within the project is both: the project manager and the programmer. I am more comfortable in the project manager role, architectural role, analytical role than the developer's. Has any of you some good habbits to observe in project development? Thanks to you all! =)

    Read the article

  • [NEWVERSION]algorithm || method to write prog[UNSOLVED] [closed]

    - by fatai
    I am one of the computer science student. Everyone solve problem with a different or same method, ( but actually I dont know whether they use method or I dont know whether there are such common method to approach problem.) if there are common method, What is it ? If there are different method, which method are you using ? All teacher give us problem which in simple form sometimes, but they donot introduce any approach or method(s) so that we cannot make a decision to choose the method then apply that one to problem , afterward find solution then write code.No help from teacher , push us to find method to solve homework. Ex: my friend is using no method , he says "I start to construct algorithm while I try to write prog." I have found one method when I failed the course, More accurately, my method: When I counter problem in language , I will get more paper and then ; first, input/ output step ; my prog will take this / these there argument(s) and return namely X , ex : in c, input length is not known and at same type , so I must use pointer desired output is in form of package , so use structure second, execution part ; in that step , I am writing all step which are goes to final output ex : in python ; 1.) [ + , [- , 4 , [ * , 1 , 2 ]], 5] 2.) [ + , [- , 4 , 2 ],5 ] 3.) [ + , 2 , 5] 4.) 7 ==> return 7 third, I will write test code ex : in c++ input : append 3 4 5 6 vector_x remove 0 1 desired output vector_x holds : 5 6 now, my other question is ; What is/are other method(s) which have/has been; used to construct class :::: for c++ , python, java used to communicate classes / computers used for solving embedded system problem ::::: for c by other user? Some programmer uses generalized method without considering prog-language(java , perl .. ), what is this method ? Why I wonder , because I learn if you dont costruct algorithm on paper, you may achieve your goal. Like no money no lunch , I can say no algorithm no prog therefore , feel free when you write your own method , a way which is introduced by someone else but you are using and you find it is so efficient

    Read the article

  • Multiple Cookie Generation Issue

    - by Shannon
    Hi all, jQuery newbie here. I need to be able to set multiple cookies within the code without have to change out this variable each and every time. Is there any way to make this code generate unique cookies for different pages? As it is now, I'm having to rename that variable for each page that the jQuery animations exist on. (sbbcookiename) Background on the issue: We are having issues with the sliders not autoplaying once one has already been triggered, due to it the cookie having been cached. Thanks for your help. (function(){ jQuery.noConflict(); var _TIMEOUT= 1000, initTimer= 0, sbLoaded= false, _re= null ; initTimer= setTimeout(initSlider, _TIMEOUT); jQuery(document).ready(initSlider); function initSlider(){ if(sbLoaded) return; if (jQuery('#campaign_name').length > 0) { var sbbcookiename = jQuery('#campaign_name').attr('class'); } else { var sbbcookiename = "slider728x90"; } var slideTimeout //timer ,sbTrigger = jQuery('#slidebartrigger') //convenience ,sbFirstSlide = (document.cookie.indexOf(sbbcookiename) == -1) //check cookie for 'already seen today' ; clearTimeout(initTimer); sbLoaded= true; function toggleSlideboxes(){ if(slideTimeout) clearTimeout(slideTimeout); var isDown = sbTrigger.is('.closeSlide'); jQuery('#slidebar')['slide' + (isDown ? 'Up' : 'Down')]((isDown ? 1000 : 1000), function(){ if(sbFirstSlide){ //if 'first time today' then clear for click-to-replay sbTrigger.removeClass('firstSlide'); sbFirstSlide = false; } sbTrigger[(isDown ? 'remove' : 'add') + 'Class']('closeSlide').one('click', toggleSlideboxes); if(!isDown) slideTimeout = setTimeout(toggleSlideboxes, 4000); }); } if(sbFirstSlide){ //not seen yet today so set a cookie for expire tomorrow, then toggle the slide boxes... var oneDay = new Date(); oneDay.setUTCDate(oneDay.getUTCDate()+1); oneDay.setUTCHours(0, 0, 0, 0); //set to literally day-by-day, rather than 24 hours document.cookie=sbbcookiename+"=true;path=/;expires="+oneDay.toUTCString(); toggleSlideboxes(); }else{ //already seen today so show the trigger and set a click event on it... sbTrigger.removeClass('firstSlide').one('click', toggleSlideboxes); } } })();

    Read the article

  • Creating a spam list with a web crawler in python

    - by user313623
    Hey guys, I'm not trying to do anything malicious here, I just need to do some homework. I'm a fairly new programmer, I'm using python 3.0, and I having difficulty using recursion for problem-solving. I've been stuck on this question for quite a while. Here's the assignment: Write a recursive method spam(url, n) that takes a url of a web page as input and a non-negative integer n, collects all the email address contained in the web page and adds them to a global dictionary variable spam_dict, and then recursively calls itself on every http hyperlink contained in the web page. You will use a dictionary so only one copy of every email address is save; your dictionary will store (key,value) pairs (email, email). The recursive call should use the parameter n-1 instead of n. If n = 0, you should collect the email addresses but no recursive calls should be made. The parameter n is used to limit the recursion to at most depth n. You will need to use the solutions of the two above problems; you method spam() will call the methods links2() and emails() and possibly other functions as well. Notes: 1. running spam() directly will produce no output on the screen; to find your spam_dict, you will need to read the value of spam_dict, and you will also need to reset it to the empty dictionary before every run of spam. 2. Recall how global variables are used. Usage: spam_dict = {} spam('http://reed.cs.depaul.edu/lperkovic/csc242/test1.html',0) spam_dict.keys() dict_keys([]) spam_dict = {} spam('http://reed.cs.depaul.edu/lperkovic/csc242/test1.html',1) spam_dict.keys() dict_keys(['[email protected]', '[email protected]']) So far, I've written a function that traverses web pages and puts all the links in a nice little list, and what I wanted to do was call that functions. And why would I use recursion on a dictionary? And how? I don't understand how n ties into all of this. def links2(url): content = str(urlopen(url).read()) myparser = MyHTMLParser() myparser.feed(content) lst = myparser.get() mergelst = [] for link in lst: mergelst.append(urljoin(lst[0],link)) print(mergelst) Any input (except why spam is bad) would be greatly appreciated. Also, I realize that the above function could probably look better, if you have a way to do it, I'm all ears. However, all I need is the point is for the program to produce the proper output.

    Read the article

  • How to set a key binding to make Emacs as transparent/opaque as I want?

    - by Vivi
    I want to have a command in Emacs to make it as opaque/transparent as I want (refer to the fabulous question that pointed out that transparency is possible in Emacs, and the EmacsWiki page linked there which has the code I am using below). The EmacsWiki code sets "C-c t" to toggle the previously set transparency on and off: ;;(set-frame-parameter (selected-frame) 'alpha '(<active> [<inactive>])) (set-frame-parameter (selected-frame) 'alpha '(85 50)) (add-to-list 'default-frame-alist '(alpha 85 50)) enter code here(eval-when-compile (require 'cl)) (defun toggle-transparency () (interactive) (if (/= (cadr (find 'alpha (frame-parameters nil) :key #'car)) 100) (set-frame-parameter nil 'alpha '(100 100)) (set-frame-parameter nil 'alpha '(85 60)))) (global-set-key (kbd "C-c t") 'toggle-transparency) What I would like to do is to be able to choose the % transparency when I am in Emacs. If possible, I would like a command where I type for example "C-c t N" (where N is the % opaqueness) for the active frame, and then "M-c t N" for the inactive window. If that can't be done like that, then maybe a command where if I type "C-c t" it asks me for the number which gives the opaqueness of the active window (and the same for the inactive window using "M-c t"). Thanks in advance for your time :) Below are just some comments that are not important to answer the question if you are not interested: I really want this because when I told my supervisor I was learning Emacs he said TexShop is much better and that I am using software from the 80's. I told him about the wonders of Emacs and he said TexShop has all of it and more. I matched everything he showed me except for the transparency (though he couldn't match the preview inside Emacs from preview-latex). I found the transparency thing by chance, and now I want to show him Emacs rules! I imagine this will be a piece of cake for some of you, and even though I could get it done if I spent enough time trying to learn lisp or reading around, I am not a programmer and I have only been using Emacs and a mac for a week. I am lost already as it is! So thanks in advance for your time and help - I will learn lisp eventually!

    Read the article

  • What Can I Do To One Of My Team Number (Good Friend As Well) Who Lost His Passion.

    - by skyflyer
    It seems this question is not program related, but there are lot of similar questions. So please bear with me! By the way, I am programmer and my team is also charging a software project. And SO is the only place which solved me lot of thorny troubles!THANK YOU GUYS! I joined my company with him years ago. At that time he was quite passionate on his job which is a front-end development. He gave us lot of useful suggestions concerning his work like design. And I believed he was a smart guy. I believe he still is smart too by the way. One years later, however, he seemed lost his passion and fooling around every day, did not care about his work any more and produced poorwork. Even worse he literally stopped learning new skills and honing his work related skills. For me it is horrible, we got to keep abreast with new technology development, otherwise we will be throw out. Since we were just coworkers, I did not care about it too much except mentioned my thoughts several times. But last month, we resembled a new group and assigned very important project. And I am the team leader, sadly! My boss gave me lot of support and expectation as well. I did a pretty good job before and I am very optimism to our future. But as a team, if my team does not work hard, we will be doomed to failure no matter how hard I work and push. In order to revitalize his passion, I tried couple of ways like talking to him about my concern and my boss's angry. I offered his new task which is quite new to him. I even persuaded my boss to give him new incentive package. But all of them knocked wall. His reaction was just he did not care. Even worse he did not want to talk about his situation. I want to be hard on him, but since we are friends and coworkers, I really can not see it will work. Even it works, I can not so quickly change my self from friend and coworker into manager. As a novice in management, I am really overwhelmed! I do not want get him fired, we are friends and I do not see him fired as my team number. What can I do? Thank you guys!

    Read the article

  • Can you pass by reference in Java?

    - by dbones
    Hi. Sorry if this sounds like a newbie question, but the other day a Java developer mentioned about passing a paramter by reference (by which it was ment just pass a Reference object) From a C# perspective I can pass a reference type by value or by reference, this is also true to value types I have written a noddie console application to show what i mean.. can i do this in Java? namespace ByRefByVal { class Program { static void Main(string[] args) { //Creating of the object Person p1 = new Person(); p1.Name = "Dave"; PrintIfObjectIsNull(p1); //should not be null //A copy of the Reference is made and sent to the method PrintUserNameByValue(p1); PrintIfObjectIsNull(p1); //the actual reference is passed to the method PrintUserNameByRef(ref p1); //<-- I know im passing the Reference PrintIfObjectIsNull(p1); Console.ReadLine(); } private static void PrintIfObjectIsNull(Object o) { if (o == null) { Console.WriteLine("object is null"); } else { Console.WriteLine("object still references something"); } } /// <summary> /// this takes in a Reference type of Person, by value /// </summary> /// <param name="person"></param> private static void PrintUserNameByValue(Person person) { Console.WriteLine(person.Name); person = null; //<- this cannot affect the orginal reference, as it was passed in by value. } /// <summary> /// this takes in a Reference type of Person, by reference /// </summary> /// <param name="person"></param> private static void PrintUserNameByRef(ref Person person) { Console.WriteLine(person.Name); person = null; //this has access to the orginonal reference, allowing us to alter it, either make it point to a different object or to nothing. } } class Person { public string Name { get; set; } } } If it java cannot do this, then its just passing a reference type by value? (is that fair to say) Many thanks Bones

    Read the article

  • Function Point Analysis -- a seriously over-estimating technique?

    - by kizzx2
    I know questions about FPA has been asked numerous times before, but this time I'm taking a more analytical angle at it, backed up with data. 1. First, some data This question is based on a tutorial. He had a "Sample Count" section where he demonstrated it step by step. You can see some screenshots of his sample application here. In the end, he calculated the unadjusted FP to be 99. There is another article on InformIT with industry data on typical hour/FP. It ranges from 2 hours/FP to 27.4 hours/FP. Let's try to stick with 2 for the moment (since SO readers are probably the more efficient crowd :p). 2. Reality check!? Now just check out the screenshots again. Do a little math here 99 * 2 = 198 hours 198 hours / 40 hours per week = 5 weeks Seriously? That sample application is going to take 5 weeks to implement? Is it just my feeling that it wouldn't take any decent programmer longer than one week to have it completed? Now let's try estimating the cost of the project. We'll use New York's minimum wage at the moment (Wikipedia), which is $7.25 198 * 7.25 = $1435.5 From what I could see from the screenshots, this application is a small excel-improvement app. I could have bought MS Office Pro for 200 bucks which gives me greater interoperability (.xls files) and flexibility (spreadsheets). (For the record, that same Web site has another article discussing productivity. It seems like they typically use 4.2 hours/FP, which gives us even more shocking stats: 99 * 4.2 = 415 hours = 10 weeks = almost 3 whopping months! 415 hours * $7.25 = $3000 zomg (That's even assuming that all our poor coders get the minimum wage!) 3. Am I missing something here? Right now, I could come up with several possible explanation: FPA is really only suited for bigger projects (1000+ FPs) so it becomes extremely inaccurate at smaller scale. The hours/FP metric fluctuates abruptly from team to team, project to project. For a small project like this, we could have used something like 0.5 hour/FP or something. (Now this kind of makes the whole estimation thing pointless, unless my firm does the same type of projects for several years with the same team, not really common.) From my experience with several software metrics, Function Point is really not a lightweight metric. If the hour/FP thing fluctuates so much, then what's the point, maybe I could have gone with User Story Points which is a lot faster to get and arguably almost as uncertain. What would be the FP experts' answers to this?

    Read the article

  • Display all images from outside web root folder using PHP

    - by micmola
    Hello, I want to display all images that are stored outside my web root folder. Please help me. I am only able to display one image repeatedly. For example, if I have 5 images in my folder, only one image is displayed on my browser 5 times. Please help me on this. I've been working on this problem for over a month now. I'm a newbie. Help. Thank you. Here is the code I'm using. images.php <?php // Get our database connector require("includes/copta.php"); // Grab the data from our people table $sql = "select * from people"; $result = mysql_query($sql) or die ("Could not access DB: " . mysql_error()); $imgLocation = " /uploadfile/"; while ($row = mysql_fetch_array($result)) { $imgName = $row["filename"]; $imgPath = $imgLocation . $imgName; echo "<img src=\"call_images.php?imgPath=" . $imgName . "\" alt=\"\"><br/>"; echo $row['id'] . " " . $imgName. "<br />"; } ?> call_images.php <?php // Get our database connector require("includes/copta.php"); $imgLocation = '/ uploadz/'; $sql = "select * from people"; $result = mysql_query($sql) or die ("Could not access DB: " . mysql_error()); while ($row = mysql_fetch_array($result)) { $imgName = $row["filename"]; $imgPath = $imgLocation . $imgName; // Make sure the file exists if(!file_exists($imgPath) || !is_file($imgPath)) { header('HTTP/1.0 404 Not Found'); die('The file does not exist'); } // Make sure the file is an image $imgData = getimagesize($imgPath); if(!$imgData) { header('HTTP/1.0 403 Forbidden'); die('The file you requested is not an image.'); } // Set the appropriate content-type // and provide the content-length. header("Pragma: public"); header("Expires: 0"); header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); header("Content-Type: image/jpg"); header("Content-length: " . filesize($imgPath)); // Print the image data readfile($imgPath); exit(); } ?>

    Read the article

  • Multiple infowindows - tearing my hair out

    - by thewinchester
    Ok, I'll admit I'm nowhere near the best programmer on the planet - and I'm used to the answer staring me right in the face but not making sense of it. Problem I need to display multiple markers on a map, each with their own infowindow. I have created the individual markers without a problem, but don't know how to create the infowindows for each. Steps so far I am generating a map using the V3 API within an ASP-based website, with markers being created from a set of DB records. The markers are created by looping through a rs and defining a marker() with the relevant variables: var myLatlng = new google.maps.LatLng(lat,long); var marker = new google.maps.Marker({ map: map, position: myLatlng, title: 'locationname', icon: 'http://google-maps-icons.googlecode.com/files/park.png' }); This is creating all the relevant markers in their correct locations. What I need to do now, and am not sure of how to achieve is give each of them their own unique infowindow which I can use to display information and links relevant to that marker. Source <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script language="javascript"> $(document).ready(function() { //Google Maps var myOptions = { zoom: 5, center: new google.maps.LatLng(-26.66, 122.25), mapTypeControl: false, mapTypeId: google.maps.MapTypeId.ROADMAP, navigationControl: true, navigationControlOptions: { style: google.maps.NavigationControlStyle.SMALL } } var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions); <!-- While locations_haslatlong not BOF.EOF --> <% While ((Repeat1__numRows <> 0) AND (NOT locations_haslatlong.EOF)) %> var myLatlng = new google.maps.LatLng(<%=(locations_haslatlong.Fields.Item("llat").Value)%>,<%=(locations_haslatlong.Fields.Item("llong").Value)%>); var marker = new google.maps.Marker({ map: map, position: myLatlng, title: '<%=(locations_haslatlong.Fields.Item("ldescription").Value)%>', icon: 'http://google-maps-icons.googlecode.com/files/park.png', clickable: true, }); <% Repeat1__index=Repeat1__index+1 Repeat1__numRows=Repeat1__numRows-1 locations_haslatlong.MoveNext() Wend %> <!-- End While locations_haslatlong not BOF.EOF --> google.maps.event.addListener(marker, 'click', function() { infowindow.open(map,marker); }); google.maps.event.addListener(marker, 'dblclick', function() { map.setZoom(14); }); });

    Read the article

  • How do we, as a community, help encourage programming in public schools? (Or state Schools for the U

    - by NoMoreZealots
    PRIMARY MOTIVATION My office gets involved with the "First Robotics" competitions and one thing that lingers year to year is the students typically have no preparation for doing even simple programming as part of the public schools system. While the science classes provide some basic grasp of mechanical and electrical concepts, by in large computer programming gets no coverage from the curriculum. (This my be different in other areas of the country/world.) What makes it worse is there is only a short period of time you have to prepare the student's and help them design the robot. Talking to some professors from local colleges, it's a problem because you can't assume even the most basic understanding for freshman CS majors. Languages like Python, Lua and BASIC are simple enough for at least high school level students, if not younger. SCOPE So how do you get public schools to support a programming, at least to the level of "Try it in BASIC" examples that used to be at the end of a chapter in my Algebra book? At least enough to prepare them for event's such as the FIRST Robotic competitions. Which the primary objectives are to teach problem solving and team work, and to possible foster an interest in Math, Science and Engineering in general. (Not force feed to them, as some people her seem to be implying.) Edit: Why teach kids: (Since 2000 CS enrollment in US colleges has decreased by 70% while college enrollment has increased, this is a PROBLEM.) Saying there is no value in teaching someone programming in Jr./High school because they might think "they know programming." Is like saying there's no value in teaching High school science and physics, because they might decide they "know physics." Leading to abuse like: "I passed a high school physics class, I'm going to develop a Unified Quantum Gravitational Theory." Better Prepared students are better students. Instead it would allows college programs to raise the bar on the entry level courses, allowing students to be weeded out based on their understanding of more advanced material. Plus people who did poorly in that in topic in High school aren't as likely to say "I think there's money in computer's so I'll computer science." Plus if people take it in high school and decide THEN that it's not for them, it's better than them wasting their money to PAY a college to figure that out. The result is that people who take the degree are more likely to succeed and be there for the RIGHT reasons. (i.e. It's what they REALLY want to do. And that's REALLY the key to being good at anything.) Programming is like anything else, the more practice and genuine interest you have the better you get. If you start them later, they get less practice. The earlier give them the opportunity to start, the more practice they will get. All other things equal, the more practice the better the programmer.

    Read the article

  • Autocomplete server-side implementation

    - by toluju
    What is a fast and efficient way to implement the server-side component for an autocomplete feature in an html input box? I am writing a service to autocomplete user queries in our web interface's main search box, and the completions are displayed in an ajax-powered dropdown. The data we are running queries against is simply a large table of concepts our system knows about, which matches roughly with the set of wikipedia page titles. For this service obviously speed is of utmost importance, as responsiveness of the web page is important to the user experience. The current implementation simply loads all concepts into memory in a sorted set, and performs a simple log(n) lookup on a user keystroke. The tailset is then used to provide additional matches beyond the closest match. The problem with this solution is that it does not scale. It currently is running up against the VM heap space limit (I've set -Xmx2g, which is about the most we can push on our 32 bit machines), and this prevents us from expanding our concept table or adding more functionality. Switching to 64-bit VMs on machines with more memory isn't an immediate option. I've been hesitant to start working on a disk-based solution as I am concerned that disk seek time will kill performance. Are there possible solutions that will let me scale better, either entirely in memory or with some fast disk-backed implementations? Edits: @Gandalf: For our use case it is important the the autocompletion is comprehensive and isn't just extra help for the user. As for what we are completing, it is a list of concept-type pairs. For example, possible entries are [("Microsoft", "Software Company"), ("Jeff Atwood", "Programmer"), ("StackOverflow.com", "Website")]. We are using Lucene for the full search once a user selects an item from the autocomplete list, but I am not yet sure Lucene would work well for the autocomplete itself. @Glen: No databases are being used here. When I'm talking about a table I just mean the structured representation of my data. @Jason Day: My original implementation to this problem was to use a Trie, but the memory bloat with that was actually worse than the sorted set due to needing a large number of object references. I'll read on the ternary search trees to see if it could be of use.

    Read the article

  • Recommended textbook for machine-level programming?

    - by Norman Ramsey
    I'm looking at textbooks for an undergraduate course in machine-level programming. If the perfect book existed, this is what it would look like: Uses examples written in C or assembly language, or both. Covers machine-level operations such as two's-complement integer arithmetic, bitwise operations, and floating-point arithmetic. Explains how caches work and how they affect performance. Explains machine instructions or assembly instructions. Bonus if the example assembly language includes x86; triple bonus if it includes x86-64 (aka AMD64). Explains how C values and data structures are represented using hardware registers and memory. Explains how C control structures are translated into assembly language using conditional and unconditional branch instructions. Explains something about procedure calling conventions and how procedure calls are implemented at the machine level. Books I might be interested in would probably have the words "machine organization" or "computer architecture" in the title. Here are some books I'm considering but am not quite happy with: Computer Systems: A Programmer's Perspective by Randy Bryant and Dave O'Hallaron. This is quite a nice book, but it's a book for a broad, shallow course in systems programming, and it contains a great deal of material my students don't need. Also, it is just out in a second edition, which will make it expensive. Computer Organization and Design: The Hardware/Software Interface by Dave Patterson and John Hennessy. This is also a very nice book, but it contains way more information about how the hardware works than my students need. Also, the exercises look boring. Finally, it has a show-stopping bug: it is based very heavily on MIPS hardware and the use of a MIPS simulator. My students need to learn how to use DDD, and I can't see getting this to work on a simulator. Not to mention that I can't see them cross-compiling their code for the simulator, and so on and so forth. Another flaw is that the book mentions the x86 architecture only to sneer at it. I am entirely sympathetic to this point of view, but news flash! You guys lost! Write Great Code Vol I: Understanding the Machine by Randall Hyde. I haven't evaluated this book as thoroughly as the other two. It has a lot of what I need, but the translation from high-level language to assembler is deferred to Volume Two, which has mixed reviews. My students will be annoyed if I make them buy a two-volume series, even if the price of those two volumes is smaller than the price of other books. I would really welcome other suggestions of books that would help students in a class where they are to learn how C-language data structures and code are translated to machine-level data structures and code and where they learn how to think about performance, with an emphasis on the cache.

    Read the article

  • XML - how to use namespace prefixes

    - by Asbie
    I have this XML at http://localhost/file.xml: <?xml version="1.0" encoding="utf-8"?> <val:Root xmlns:val="http://www.hw-group.com/XMLSchema/ste/values.xsd"> <Agent> <Version>2.0.3</Version> <XmlVer>1.01</XmlVer> <DeviceName>HWg-STE</DeviceName> <Model>33</Model> <vendor_id>0</vendor_id> <MAC>00:0A:DA:01:DA:DA</MAC> <IP>192.168.1.1</IP> <MASK>255.255.255.0</MASK> <sys_name>HWg-STE</sys_name> <sys_location/> <sys_contact> HWg-STE:For more information try http://www.hw-group.com </sys_contact> </Agent> <SenSet> <Entry> <ID>215</ID> <Name>Home</Name> <Units>C</Units> <Value>27.7</Value> <Min>10.0</Min> <Max>40.0</Max> <Hyst>0.0</Hyst> <EmailSMS>1</EmailSMS> <State>1</State> </Entry> </SenSet> </val:Root> I am trying to read this from my c# code: static void Main(string[] args) { var xmlDoc = new XmlDocument(); xmlDoc.Load("http://localhost/file.xml"); XmlElement root = xmlDoc.DocumentElement; // Create an XmlNamespaceManager to resolve the default namespace. XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmlDoc.NameTable); nsmgr.AddNamespace("val", "http://www.hw-group.com/XMLSchema/ste/values.xsd"); XmlNodeList nodes = root.SelectNodes("/val:SenSet/val:Entry"); foreach (XmlNode node in nodes) { string name = node["Name"].InnerText; string value = node["Value"].InnerText; Console.Write("name\t{0}\value\t{1}", name, value); } Console.ReadKey(); } } Problem is that the node is empty. I understand this is a common newbie problem when reading XML, still not able to solve what I am doing wrong, probably something with the Namespace "val" ?

    Read the article

  • How to check for palindrome using Python logic

    - by DrOnline
    My background is only a 6 month college class in basic C/C++, and I'm trying to convert to Python. I may be talking nonsense, but it seems to me C, at least at my level, is very for-loop intensive. I solve most problems with these loops. And it seems to me the biggest mistake people do when going from C to Python is trying to implement C logic using Python, which makes things run slowly, and it's just not making the most of the language. I see on this website: http://hyperpolyglot.org/scripting (serach for "c-style for", that Python doesn't have C-style for loops. Might be outdated, but I interpret it to mean Python has its own methods for this. I've tried looking around, I can't find much up to date (Python 3) advice for this. How can I solve a palindrome challenge in Python, without using the for loop? I've done this in C in class, but I want to do it in Python, on a personal basis. The problem is from the Euler Project, great site btw. def isPalindrome(n): lst = [int(n) for n in str(n)] l=len(lst) if l==0 || l==1: return True elif len(lst)%2==0: for k in range (l) ##### else: while (k<=((l-1)/2)): if (list[]): ##### for i in range (999, 100, -1): for j in range (999,100, -1): if isPalindrome(i*j): print(i*j) break I'm missing a lot of code here. The five hashes are just reminders for myself. Concrete questions: 1) In C, I would make a for loop comparing index 0 to index max, and then index 0+1 with max-1, until something something. How to best do this in Python? 2) My for loop (in in range (999, 100, -1), is this a bad way to do it in Python? 3) Does anybody have any good advice, or good websites or resources for people in my position? I'm not a programmer, I don't aspire to be one, I just want to learn enough so that when I write my bachelor's degree thesis (electrical engineering), I don't have to simultaneously LEARN an applicable programming language while trying to obtain good results in the project. "How to go from basic C to great application of Python", that sort of thing. 4) Any specific bits of code to make a great solution to this problem would also be appreciated, I need to learn good algorithms.. I am envisioning 3 situations. If the value is zero or single digit, if it is of odd length, and if it is of even length. I was planning to write for loops... PS: The problem is: Find the highest value product of two 3 digit integers that is also a palindrome.

    Read the article

< Previous Page | 212 213 214 215 216 217 218 219 220 221 222 223  | Next Page >