Search Results

Search found 16554 results on 663 pages for 'programmers identity'.

Page 123/663 | < Previous Page | 119 120 121 122 123 124 125 126 127 128 129 130  | Next Page >

  • EXCEL VBA STUDENTS DATABASE [on hold]

    - by BENTET
    I AM DEVELOPING AN EXCEL DATABASE TO RECORD STUDENTS DETAILS. THE HEADINGS OF THE TABLE ARE DATE,YEAR, PAYMENT SLIP NO.,STUDENT NUMBER,NAME,FEES,AMOUNT PAID, BALANCE AND PREVIOUS BALANCE. I HAVE BEEN ABLE TO PUT UP SOME CODE WHICH IS WORKING, BUT THERE ARE SOME SETBACKS THAT I WANT TO BE ADDRESSED.I ACTUALLY DEVELOPED A USERFORM FOR EACH PROGRAMME OF THE INSTITUTION AND ASSIGNED EACH TO A SPECIFIC SHEET BUT WHENEVER I ADD A RECORD, IT DOES NOT GO TO THE ASSIGNED SHEET BUT GOES TO THE ACTIVE SHEET.ALSO I WANT TO HIDE ALL SHEETS AND BE WORKING ONLY ON THE USERFORMS WHEN THE WORKBOOK IS OPENED.ONE PROBLEM AM ALSO FACING IS THE UPDATE CODE.WHENEVER I UPDATE A RECORD ON A SPECIFIC ROW, IT RATHER EDIT THE RECORD ON THE FIRST ROW NOT THE RECORD EDITED.THIS IS THE CODE I HAVE BUILT SO FAR.I AM VIRTUALLY A NOVICE IN PROGRAMMING. Private Sub cmdAdd_Click() Dim lastrow As Long lastrow = Sheets("Sheet4").Range("A" & Rows.Count).End(xlUp).Row Cells(lastrow + 1, "A").Value = txtDate.Text Cells(lastrow + 1, "B").Value = ComBox1.Text Cells(lastrow + 1, "C").Value = txtSlipNo.Text Cells(lastrow + 1, "D").Value = txtStudentNum.Text Cells(lastrow + 1, "E").Value = txtName.Text Cells(lastrow + 1, "F").Value = txtFees.Text Cells(lastrow + 1, "G").Value = txtAmountPaid.Text txtDate.Text = "" ComBox1.Text = "" txtSlipNo.Text = "" txtStudentNum.Text = "" txtName.Text = "" txtFees.Text = "" txtAmountPaid.Text = "" End Sub Private Sub cmdClear_Click() txtDate.Text = "" ComBox1.Text = "" txtSlipNo.Text = "" txtStudentNum.Text = "" txtName.Text = "" txtFees.Text = "" txtAmountPaid.Text = "" txtBalance.Text = "" End Sub Private Sub cmdClearD_Click() txtDate.Text = "" ComBox1.Text = "" txtSlipNo.Text = "" txtStudentNum.Text = "" txtName.Text = "" txtFees.Text = "" txtAmountPaid.Text = "" txtBalance.Text = "" End Sub Private Sub cmdClose_Click() Unload Me End Sub Private Sub cmdDelete_Click() 'declare the variables Dim findvalue As Range Dim cDelete As VbMsgBoxResult 'check for values If txtStudentNum.Value = "" Or txtName.Value = "" Or txtDate.Text = "" Or ComBox1.Text = "" Or txtSlipNo.Text = "" Or txtFees.Text = "" Or txtAmountPaid.Text = "" Or txtBalance.Text = "" Then MsgBox "There is not data to delete" Exit Sub End If 'give the user a chance to change their mind cDelete = MsgBox("Are you sure that you want to delete this student", vbYesNo + vbDefaultButton2, "Are you sure????") If cDelete = vbYes Then 'delete the row Set findvalue = Sheet4.Range("D:D").Find(What:=txtStudentNum, LookIn:=xlValues) findvalue.EntireRow.Delete End If 'clear the controls txtDate.Text = "" ComBox1.Text = "" txtSlipNo.Text = "" txtStudentNum.Text = "" txtName.Text = "" 'txtFees.Text = "" txtAmountPaid.Text = "" txtBalance.Text = "" End Sub Private Sub cmdSearch_Click() Dim lastrow As Long Dim currentrow As Long Dim studentnum As String lastrow = Sheets("Sheet4").Range("A" & Rows.Count).End(xlUp).Row studentnum = txtStudentNum.Text For currentrow = 2 To lastrow If Cells(currentrow, 4).Text = studentnum Then txtDate.Text = Cells(currentrow, 1) ComBox1.Text = Cells(currentrow, 2) txtSlipNo.Text = Cells(currentrow, 3) txtStudentNum.Text = Cells(currentrow, 4).Text txtName.Text = Cells(currentrow, 5) txtFees.Text = Cells(currentrow, 6) txtAmountPaid.Text = Cells(currentrow, 7) txtBalance.Text = Cells(currentrow, 8) End If Next currentrow txtStudentNum.SetFocus End Sub Private Sub cmdSearchName_Click() Dim lastrow As Long Dim currentrow As Long Dim studentname As String lastrow = Sheets("Sheet4").Range("A" & Rows.Count).End(xlUp).Row studentname = txtName.Text For currentrow = 2 To lastrow If Cells(currentrow, 5).Text = studentname Then txtDate.Text = Cells(currentrow, 1) ComBox1.Text = Cells(currentrow, 2) txtSlipNo.Text = Cells(currentrow, 3) txtStudentNum.Text = Cells(currentrow, 4) txtName.Text = Cells(currentrow, 5).Text txtFees.Text = Cells(currentrow, 6) txtAmountPaid.Text = Cells(currentrow, 7) txtBalance.Text = Cells(currentrow, 8) End If Next currentrow txtName.SetFocus End Sub Private Sub cmdUpdate_Click() Dim tdate As String Dim tlevel As String Dim tslipno As String Dim tstudentnum As String Dim tname As String Dim tfees As String Dim tamountpaid As String Dim currentrow As Long Dim lastrow As Long 'If Cells(currentrow, 5).Text = studentname Then 'txtDate.Text = Cells(currentrow, 1) lastrow = Sheets("Sheet4").Range("A" & Columns.Count).End(xlUp).Offset(0, 1).Column For currentrow = 2 To lastrow tdate = txtDate.Text Cells(currentrow, 1).Value = tdate txtDate.Text = Cells(currentrow, 1) tlevel = ComBox1.Text Cells(currentrow, 2).Value = tlevel ComBox1.Text = Cells(currentrow, 2) tslipno = txtSlipNo.Text Cells(currentrow, 3).Value = tslipno txtSlipNo = Cells(currentrow, 3) tstudentnum = txtStudentNum.Text Cells(currentrow, 4).Value = tstudentnum txtStudentNum.Text = Cells(currentrow, 4) tname = txtName.Text Cells(currentrow, 5).Value = tname txtName.Text = Cells(currentrow, 5) tfees = txtFees.Text Cells(currentrow, 6).Value = tfees txtFees.Text = Cells(currentrow, 6) tamountpaid = txtAmountPaid.Text Cells(currentrow, 7).Value = tamountpaid txtAmountPaid.Text = Cells(currentrow, 7) Next currentrow txtDate.SetFocus ComBox1.SetFocus txtSlipNo.SetFocus txtStudentNum.SetFocus txtName.SetFocus txtFees.SetFocus txtAmountPaid.SetFocus txtBalance.SetFocus End Sub PLEASE I WAS THINKING IF I CAN DEVELOP SOMETHING THAT WILL USE ONLY ONE USERFORM TO SEND DATA TO DIFFERENT SHEETS IN THE WORKBOOK.

    Read the article

  • Troubleshooting VC++ DLL in VB.Net

    - by Jolyon
    I'm trying to make a solution in Visual Studio that consists of a VC++ DLL and a VB.Net application. To figure this out, I created a VC++ Class Library project, with the following code (I removed all the junk the wizard creates): mathfuncs.cpp: #include "MathFuncs.h" namespace MathFuncs { double MyMathFuncs::Add(double a, double b) { return a + b; } } mathfuncs.h: using namespace System; namespace MathFuncs { public ref class MyMathFuncs { public: static double Add(double a, double b); }; } This compiles quite happily. I can then add a VC++ console project to the solution, add a reference to the original project for this new project, and call it as follows: test.cpp: using namespace System; int main(array<System::String ^> ^args) { double a = 7.4; int b = 99; Console::WriteLine("a + b = {0}", MathFuncs::MyMathFuncs::Add(a, b)); return 0; } This works just fine, and will build to test.exe and mathsfuncs.dll. However, I want to use a VB.Net project to call the DLL. To do this, I add a VB.Net project to the solution, make it the startup project, and add a reference to the original project. Then, I attempt to use it as follows: MsgBox(MathFuncs.MyMathFuncs.Add(1, 2)) However, when I run this code, it gives me an error: "Could not load file or assembly 'MathFuncsAssembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format." Do I need to expose the method somehow? I'm using Visual Studio 2008 Professional.

    Read the article

  • Is there an established convention for separating Windows file names in a string?

    - by Heinzi
    I have a function which needs to output a string containing a list of file paths. I can choose the separation character but I cannot change the data type (e.g. I cannot return a List<string> or something like that). Wanting to use some well-established convention, my first intuition was to use the semicolon, similar to what Windows's PATH and Java's CLASSPATH (on Windows) environment variables do: C:\somedir\somefile.txt;C:\someotherdir\someotherfile.txt However, I was surprised to notice that ; is a valid character in an NTFS file name. So, is the established best practice to just ignore this fact (i.e. "no sane person should use ; in a file name and if they do, it's their own fault") or is there some other established character for separating Windows paths or files? (The pipe (|) might be a good choice, but I have not seen it used anywhere yet for this purpose.)

    Read the article

  • What should you leave behind for your successors?

    - by SnOrfus
    Assume that you're a sole developer leaving a job. What kind of information/material, outside of the code itself, should you create and leave behind for your replacement? An obvious answer is "whatever you would want at a new job" for sure, but it's been a while since I started a new job, and I forget what the most important things that I needed were back then. I'm thinking: accounts/passwords location of equpiment What else?

    Read the article

  • How can Swift be so much faster than Objective-C?

    - by Yellow
    Apple launched its new programming language Swift today. In the presentation, they made some performance comparisons between Objective-C and Python. The following is a picture of one of their slides, of a comparison of those three languages performing some complex object sort: There was an even more incredible graph about a performance comparison working on some encryption algorithm. Obviously this is a marketing talk, and they didn't go into detail on how this was implemented in each. I leaves me wondering though: how can a new programming language be so much faster? In this example, surely you just have a bad Objective-C compiler or you're doing something in a less efficient way? How else would you explain a 40% performance increase? I understand that garbage collection/automated reference control might produce some additional overhead, but this much?

    Read the article

  • Best practice for storing HTML coming from text fields to a database?

    - by user1767270
    I have an application that allows users to edit certain parts of text and then email that out. My question is what is the best way to store this in a Microsoft SQL Server database. Right now I have two tables, one holding the HTML data and one holding the plain text data. When the user saves the info, it replaces newlines with br's and puts it in the HTML-conntaining table and then puts the regular text in the other table. This way the text box has the newlines when they go to edit, but the table that contains the HTML data, has the BR's. This seems like a silly way to do things. What would be the best practice? Thanks.

    Read the article

  • Are CK Metrics still considered useful? Is there an open source tool to help?

    - by DeveloperDon
    Chidamber & Kemerer proposed several metrics for object oriented code. Among them, depth of inheritance tree, weighted number of methods, number of member functions, number of children, and coupling between objects. Using a base of code, they tried to correlated these metrics to the defect density and maintenance effort using covariant analysis. Are these metrics actionable in projects? Perhaps they can guide refactoring. For example weighted number of methods might show which God classes needed to be broken into more cohesive classes that address a single concern. Is there approach superseded by a better method, and is there a tool that can identify problem code, particularly in moderately large project being handed off to a new developer or team?

    Read the article

  • Writing a job requirement for a web application developer

    - by Raul Agrait
    I'm currently writing a job requirement for a software engineer position for my company, in which we are looking for a developer to work on client-side web application work. How should I title the job title / position? I don't necessarily want to call it a "Web Developer", for fear that it might attract more designer-y types. On the other hand, "Software Engineer" doesn't really give the indication that the work, while application based, will be web-based. Is "Web Application Software Engineer" a valid position title? Also, I'm somewhat torn on what the required skills set should be. I don't necessarily think that the ideal candidate should have x years of experience in say, JavaScript or ActionScript, but rather am just looking for someone who has experience in developing client-side applications, and is willing to learn and develop web applications. My current attempt at this, is that I have a section in which I state: Experience in the following frameworks and technologies are a plus, but not necessarily required for the position:

    Read the article

  • Ajax application: using SOAP vs REST ?

    - by coder
    I'm building an ajax heavy application (client-side strictly html/css/js) which will be getting all the data and using server business logic via webservices. I know REST seems to be the hot topic but I can't find any good arguments. The main argument seems to be its "light-weight". My impression so far is that wsdl/soap based services are more expressive and allow for more a more complex transfer of data. It appears that soap would be more useful in the application I'm building where the only code consuming the services will be the js downloaded in the client browser. REST on the other hand seems to have a smaller entry barrier and so can be more useful for services like twitter in allowing other developers to consume these services easily. Also, REST seems to Te better suited for simple data transfers. So in summary SOAP is useful for complex data transfer and REST is useful in simple data transfer. I'm currently under the impression that using SOAP would be best due to the complexity of the messages but perhaps there's other factors. What are your thoughts on the pros/cons of soap/rest for a heavy ajax web app? EDIT: While the wsdl is in xml, the data I'm transferring back and forth is actually in JSON. It just appears more natural to use wsdl/soap here due to the nature of the app. The verbs GET and POST may not be enough. I may want to say something like: processQueue, or executeTimer. This is why my conclusion has been wsdl/soap would be good for bridging a complex layer between two applications (client and server) whereas REST would be better (due to its simplicity) for allowing many developer-users to consume resources programmatically. So you could say the choice falls along two lines Will the app be verb-oriented (completing tasks: use soap) or noun-oriented (consuming resources: use REST) Will the api be consumed by few developers or many developers (REST is strong for many developers)? Since such an ajax heavy app would potentially use many verbs and would only be used by the client developer it appears soap/wsdl would be the best fit.

    Read the article

  • When to use shared libraries for a web framework?

    - by CamelBlues
    tl;dr: I've found myself hosting a bunch of sites running on the same web framework (symfony 1.4). Would it be helpful if I moved all of the shared library code into the same directory and shared it across the sites? more I see some advantages to this: Each site takes up less disk space Library updates (an unlikely scenario) can take place across all sites I also see some disadvantages, mostly in terms of a single point of failure and the inability to have sites using different versions of the framework. My real concern, though, is performance. I hypothesize that I will see a performance increase, since the PHP code will already be cached for all sites when they call the framework. Is this a correct hypothesis?

    Read the article

  • Integration of routes that are not resources in an MVC REST style application

    - by Emil Lerch
    I would like to keep my application relatively REST-pure for the sake of consistency, but I'm struggling philosophically with the relatively few views (maybe just one) that I'll need to build that don't relate to resources directly, and therefore do not fit into a REST style. As an example, take the home page. Ruby on rails seems to bail on their otherwise RESTful approach for this very basic need of all web sites. The home page appears special: You can get it, but a get at the resource level is supposed to give you a collection of elements. I can imagine this being the list of routes maybe, but that seems a stretch, and doesn't address anything else. Getting the home page by id doesn't seem to make a whole lot of sense - what's the element of a home collection? Again, maybe routes, but a get on a route would do what? Redirect? This feels odd. You can't delete it (arguably you could allow this for administrators) Adding a second one doesn't make sense except possibly if the elements were routes Updating it might make sense for administrators, but AFAIK REST doesn't describe updates on the resource directly, only elements of the resource (this article explicitly says "UNUSED" for PUTS on the resource) Is the "right" thing to do just to special case these types of things? At the end of the day, I can wrap my head around most of applications being gathered around resources...I can't think of another good example other than a home page, but since that's the start of an application, I think it warrants some thought.

    Read the article

  • Is LISP still useful in, and which version is most used in todays world ?

    - by shan23
    I try to teach myself a new programming language in regular intervals of time. Recently, I've read how Lisp and its dialects are at the complete opposite end of the spectrum from languages like C/C++, which made me curious enough to know more about it. However, two things are unclear to me, and I'm looking for guidance on them : Is LISP still practiced/used in todays world, or is it a legacy language like FORTRAN/COBOL ? I mean, apart from maintaining existing code, is it used on new projects at all ? What is the most widely used dialect ? I came across Scheme and Common Lisp as the 2 most prevalent dialects, and wanted your opinion as to which is the most favored/useful one to learn - and would be immensely gratified if you can suggest any resources for a rank beginner to start from. While eager to learn a language which is fundamentally different from the procedural languages I'm used to, I don't want to invest undue effort in something if its totally obsolete - I'd still learn it if it was professionally "dead", but only with an academic perspective...

    Read the article

  • Visual Web Developer 2010 Express, automated testing, and SVN

    - by Mr. Jefferson
    We have an HTML designer who is not a developer but needs to modify .aspx files from our ASP.NET 2.0 projects from time to time in order to get CSS to work properly with them. Currently, this involves giving her the .aspx page by itself, which she opens and edits via Visual Studio 2008 (her computer used to be a developer's). I'm considering getting her set up with Visual Web Developer 2010 Express and Subversion access so she can be more independent, but I wanted to make sure VS Express will work properly with what we do. So: Does VWD 2010 Express support automated tests? If no to the above, what happens when it opens a solution file that includes a test project, modifies it, and saves it? Are there any potential snags with setting up AnkhSVN with VWD 2010 Express?

    Read the article

  • Where can I find video resources of people programming?

    - by Corey
    This might be a strange question. I'm looking for videos of people actively coding something while explaining it. However, I don't want is a beginner video that delves into what variables and objects are. Nick Gravelyn's tile engine tutorial is a great example of what I'm looking for. (He actually used to host the full, unbroken video files in his site's archive, but I guess he took them down...) I tend to learn best by "action" examples; it's difficult for me to learn by reading through documentation and text tutorials, but if I see somebody actively doing a task, I can immediately register it and apply it myself. I'm hard-of-hearing, so I would really prefer that if the video has a lot of talking, it have captioning or subtitling of some sort, or at the very least, a transcript. The tile engine videos did not have captions, but the code he was writing was very self-documenting, so I understood it for the most part. I've gone through most of the relevant GoogleDevelopers and GoogleTechTalks videos on Youtube, so those need not apply. Are there any resources out there, or even websites dedicated to this kind of thing?

    Read the article

  • Best practice to query data from MS SQL Server in C Sharp?

    - by Bruno
    What is the best way to query data from a MS SQL Server in C Sharp? I know that it is not good practice to have an SQL query in the code. Is the best way to create a stored procedure and call it from C Sharp with parameters? using (var conn = new SqlConnection(connStr)) using (var command = new SqlCommand("StoredProc", conn) { CommandType = CommandType.StoredProcedure }) { conn.Open(); command.ExecuteNonQuery(); conn.Close(); }

    Read the article

  • Question about casting a class in Java with generics

    - by Florian F
    In Java 6 Class<? extends ArrayList<?>> a = ArrayList.class; gives and error, but Class<? extends ArrayList<?>> b = (Class<? extends ArrayList<?>>)ArrayList.class; gives a warning. Why is (a) an error? What is it, that Java needs to do in the assignment, if not the cast shown in (b)? And why isn't ArrayList compatible with ArrayList? I know one is "raw" and the other is "generic", but what is it you can do with an ArrayList and not with an ArrayList, or the other way around?

    Read the article

  • Explain Model View Controller

    - by Channel72
    My experience with developing dynamic websites is limited mostly to Java servlets. I've used Tomcat to develop various Java servlets, and I wouldn't hesitate to say that I'm reasonably proficient with this technology, as well as with client-side HTML/CSS/Javascript for the front-end. When I think "dynamic website", I think: user requests a URL with a query string, server receives the query, and then proceeds to output HTML dynamically in order to respond to the query. This often involves communication with a database in order to fetch requested data for display. This is basically the idea behind the doGet method of a Java HttpServlet. But these days, I'm hearing more and more about newer frameworks such as Django and Ruby on Rails, all of which take advantage of the "Model View Controller" architecture. I've read various articles which explain MVC, but I'm having trouble really understanding the benefits. I understand that the general idea is to separate business logic from UI logic, but I fail to see how this is anything really different from normal web programming. Web programming, by it's very nature, forces you to separate business logic (back-end server-side programming) from UI programming (client-side HTML or Javascript), because the two exist in entirely different spheres of programming. Question: What does MVC offer over something like a Java servlet, and more importantly, what exactly is MVC and how is it different from what you would normally do to develop a dynamic website using a more traditional approach such as a Java servlet (or even something older like CGI). If possible, when explaining MVC, please provide an example which illustrates how MVC is applied to the web development process, and how it is beneficial.

    Read the article

  • Should I migrate to MVC3?

    - by eestein
    Hi everyone. I have a MVC2 project, my question is: should I migrate to MVC3? Why? I'd like the opinion of some who already migrated, or at least used MVC3 and MVC2. Already read http://weblogs.asp.net/scottgu/archive/2011/01/13/announcing-release-of-asp-net-mvc-3-iis-express-sql-ce-4-web-farm-framework-orchard-webmatrix.aspx and I already know about the described tool for migrating: http://blogs.msdn.com/b/marcinon/archive/2011/01/13/mvc-3-project-upgrade-tool.aspx What I'd really appreciate is your valuable insight. Best regards.

    Read the article

  • Web Application Tasks Estimation

    - by Ali
    I know the answer depends on the exact project and its requirements but i am asking on the avarage % of the total time goes into the tasks of the web application development statistically from your own experiance. While developing a web application (database driven) How much % of time does each of the following activities usually takes: -- database creation & all related stored procedures -- server side development -- client side development -- layout settings and designing I know there are lots of great web application developers around here and each one of you have done fair amount of web development and as a result there could be an almost fixed percentage of time going to each of the above activities of web developments for standard projects Update : I am not expecting someone to tell me number of hours i am asking about the average percentage of time that goes on each of the activities as per your experience i.e. server side dev 50%, client side development 20% ,,,,, I repeat there will be lots of cases that differs from the standard depending on the exact requirments of each web application project but here i am asking about Avarage for standard (no special requirment) web project

    Read the article

  • Low latency technologies for c++, c# and java?

    - by James
    I've been reading job descriptions and many mention 'low latency'. However, I wondered if someone could clarify what type of technologies this would refer to? One of the adverts mentioned 'ACE' which I googled to find out was some CISCO telephony technology. If you were hiring someone for a low latency role, what would you use as a checklist for ensuring they knew about low latency programming? I'm using this to learn more about low latency programming myself.

    Read the article

  • How can I get job in company when I unfamiliar with technology [closed]

    - by Michael Z
    Sorry if I have chosen wrong stackexchange site for this question. Point me in correct place if any... How can I get job in company that have some unfamiliar technology for me in they Job Requirements list? In other words. How can I get job on Lucene if I have not any experience on Lucene, but for getting experience in Lucene I need to be involved in company that needs developers with Lucene technology experience? It is closed disk!

    Read the article

  • Obtaining Embedded Linux Experience

    - by Thomas Matthews
    As an embedded firmware developer, I have used operating systems such as WinCE, Nucleus, ThreadX, VRTX and some background loops. There are more opportunities for me if I had Linux OS experience, or perhaps some certification. In my research, the only way to get Linux experience is to have your company move to a Linux OS. All the recruiters and HR folks won't let you in the door unless you have Linux experience. I haven't found any Universities that teach Linux. Recruiters and HR want some tangible proof (starting up your own Ubuntu box or playing with it doesn't count). So, how does one get into the area of Embedded Linux without Linux experience (I have Unix and Cygwin experience, but not Linux)?

    Read the article

  • Should I use C style in C++?

    - by c.hughes
    As I've been developing my position on how software should be developed at the company I work for, I've come to a certain conclusion that I'm not entirely sure of. It seems to me that if you are programming in C++, you should not use C style anything if it can be helped and you don't absolutely need the performance improvement. This way people are kept from doing things like pointer arithmetic or creating resources with new without any RAII, etc. If this idea was enforced, seeing a char* would possibly be a thing of the past. I'm wondering if this is a conclusion others have made? Or am I being too puritanical about this?

    Read the article

  • Merge sort versus quick sort performance

    - by Giorgio
    I have implemented merge sort and quick sort using C (GCC 4.4.3 on Ubuntu 10.04 running on a 4 GB RAM laptop with an Intel DUO CPU at 2GHz) and I wanted to compare the performance of the two algorithms. The prototypes of the sorting functions are: void merge_sort(const char **lines, int start, int end); void quick_sort(const char **lines, int start, int end); i.e. both take an array of pointers to strings and sort the elements with index i : start <= i <= end. I have produced some files containing random strings with length on average 4.5 characters. The test files range from 100 lines to 10000000 lines. I was a bit surprised by the results because, even though I know that merge sort has complexity O(n log(n)) while quick sort is O(n^2), I have often read that on average quick sort should be as fast as merge sort. However, my results are the following. Up to 10000 strings, both algorithms perform equally well. For 10000 strings, both require about 0.007 seconds. For 100000 strings, merge sort is slightly faster with 0.095 s against 0.121 s. For 1000000 strings merge sort takes 1.287 s against 5.233 s of quick sort. For 5000000 strings merge sort takes 7.582 s against 118.240 s of quick sort. For 10000000 strings merge sort takes 16.305 s against 1202.918 s of quick sort. So my question is: are my results as expected, meaning that quick sort is comparable in speed to merge sort for small inputs but, as the size of the input data grows, the fact that its complexity is quadratic will become evident? Here is a sketch of what I did. In the merge sort implementation, the partitioning consists in calling merge sort recursively, i.e. merge_sort(lines, start, (start + end) / 2); merge_sort(lines, 1 + (start + end) / 2, end); Merging of the two sorted sub-array is performed by reading the data from the array lines and writing it to a global temporary array of pointers (this global array is allocate only once). After each merge the pointers are copied back to the original array. So the strings are stored once but I need twice as much memory for the pointers. For quick sort, the partition function chooses the last element of the array to sort as the pivot and scans the previous elements in one loop. After it has produced a partition of the type start ... {elements <= pivot} ... pivotIndex ... {elements > pivot} ... end it calls itself recursively: quick_sort(lines, start, pivotIndex - 1); quick_sort(lines, pivotIndex + 1, end); Note that this quick sort implementation sorts the array in-place and does not require additional memory, therefore it is more memory efficient than the merge sort implementation. So my question is: is there a better way to implement quick sort that is worthwhile trying out? If I improve the quick sort implementation and perform more tests on different data sets (computing the average of the running times on different data sets) can I expect a better performance of quick sort wrt merge sort? EDIT Thank you for your answers. My implementation is in-place and is based on the pseudo-code I have found on wikipedia in Section In-place version: function partition(array, 'left', 'right', 'pivotIndex') where I choose the last element in the range to be sorted as a pivot, i.e. pivotIndex := right. I have checked the code over and over again and it seems correct to me. In order to rule out the case that I am using the wrong implementation I have uploaded the source code on github (in case you would like to take a look at it). Your answers seem to suggest that I am using the wrong test data. I will look into it and try out different test data sets. I will report as soon as I have some results.

    Read the article

  • Is there a measure of code rot?

    - by DarenW
    I'm dealing, again, with a messy C++ application, tons of classes with confusing names, objects have pointers into each other and all over, longwinded Boost and STL data types, etc. (Pause and consider your favorite terror of messy legacy code. We probably have it.) The phrase "code rot" oft comes to mind when I work on this project. Is there a quantitative way to measure code rot? I wouldn't expect anything highly meaningful or scientific, since no other measure of code productivity or quality is so fine. I'm not looking for a mere opposite of measures of code quality, but specifically a measure of how many bad things happened after a series of maintenance software "engineers" have had turns hacking at the code. A general measure applying to any language, or many languages, would be great. If there's no such thing, at least for C++, which is a better than average language for creating messes. Maybe something involving a measure of topology of how objects connect during runtime, a count of chunks of commented out code, how mane files a typical variable's usage is scattered over, I don't know... but surely now, a decade into the 21st Century, someone has attempted to define some sort of rot measure. It would be especially interesting to automate a series of svn checkouts, measure the "rottenosity" of each, and plot the decay over time.

    Read the article

< Previous Page | 119 120 121 122 123 124 125 126 127 128 129 130  | Next Page >