Search Results

Search found 14074 results on 563 pages for 'programmers'.

Page 98/563 | < Previous Page | 94 95 96 97 98 99 100 101 102 103 104 105  | Next Page >

• Bayes Misclassification error and plot : pattern recognition [closed]

  - by user1214586

  Below is a Matlab code for Bayes classifier which classifies arbitrary numbers into their classes. training = [3;5;17;19;24;27;31;38;45;48;52;56;66;69;73;78;84;88]; target_class = [0;0;10;10;20;20;30;30;40;40;50;50;60;60;70;70;80;80]; test = [1:2:90]'; class = classify(test,training, target_class, 'diaglinear'); % Naive Bayes classifier [test class] If someone could provide code snippets for calculating the Bayes error for misclassification and accuracy.Also, is it possible to plot a scatter plot and histogram indicating the number of data points belonging to different classes? Thank you.

  Read the article

• Security programming jobs

  - by Mike Smith

  I am a student, about to finish my undergraduate in Computer Science in about a year. I am very interested in computer/network security, but I also love programming. Is there a job or subfield that is a fusion of both? I have programmed everything from games to barcode readers to web bots, and I know for sure that I want to do some kind of programming, but ideally I would like to do some kind of software development involving computer security. Any advice would be appreciated.

  Read the article

• What is the difference between "contracting" and "consulting"? [closed]

  - by Rice Flour Cookies

  Possible Duplicate: Contractor vs Consultant I read a discussion thread on Slashdot the other day where some developers were discussing taking on "consulting" and "contracting" jobs. My understanding is that both of these terms imply an individual selling his services as a programmer on his own terms as opposed to working for an employer. What is the difference between these two: "consulting" and "contracting"?

  Read the article

• 'Other' Features in a programming language

  - by user12960

  Online (i cant remember where) i saw someone mention he wishes programming language has more built in features for tools like documentation and source control. Now i dont understand what needs to be built in for source control since tools like git (sorry but i dont have much experience with others) has everything i need and is very easy to use. Documentation i can understand, perhaps the ability to generate remote procedures calls from source to some kind of IDL would be cool. But really i dont understand what features a programming language can/should have that isnt tied with code generation and syntax (except the two i mention when it comes to libraries). What ideas do you guys have? What is your wishlist?

  Read the article

• Why does void in C mean not void?

  - by Naftuli Tzvi Kay

  In strongly-typed languages like Java and C#, void (or Void) as a return type for a method seem to mean: This method doesn't return anything. Nothing. No return. You will not receive anything from this method. What's really strange is that in C, void as a return type or even as a method parameter type means: It could really be anything. You'd have to read the source code to find out. Good luck. If it's a pointer, you should really know what you're doing. Consider the following examples in C: void describe(void *thing) { Object *obj = thing; printf("%s.\n", obj->description); } void *move(void *location, Direction direction) { void *next = NULL; // logic! return next; } Obviously, the second method returns a pointer, which by definition could be anything. Since C is older than Java and C#, why did these languages adopt void as meaning "nothing" while C used it as "nothing or anything (when a pointer)"?

  Read the article

• Implement blogging system as a part of a web application/website

  - by Rana

  I am working on developing a website, where registered members will be able to write blog/tutorials and each registered site user will be a registered blogger automatically. Site news/announcements will be posted through it too. Now, will it be a wise idea to use wordpress for this purpose, or should I develop custom blogging system myself? Also, is there any impact if I use a subdomain for the blog section. user same domain (sub directory url) for the blog section. Looking forward to hear your feedback/comments/suggestions. Thanks.

  Read the article

• Which simple Java JPA ORM tool to use ?

  - by Guillaume

  What Java ORM library implementing JPA that match following criteria would you recommend and why ? free & open source alive (at least bug fixes and a mailing list) with good documentation simple not hibernate (this one is well-known :-) ) I need to select a simple ORM tool that can be set up in minutes without and easy to understand for setting simple CRUD daos. A query builder ill be an interesting plus. Later I can have to move to Hibernate, that's why being JPA compliant is a must. I have found some candidates on the web, but not so much feedback, so I will gladly take your advices on the topic. ----- EDIT --------- I have been successfully testing ebean/avaje with a small test cases. Any one has a feedback on using this tool in production ?

  Read the article

• Java HttpURLConnection class Program

  - by pandu

  I am learning java. Here is the sample code of HttpURLConnection class usage in some text book import java.net.*; import java.io.*; import java.util.*; class HttpURLDemo { public static void main(String args[]) throws Exception { URL hp = new URL("http://www.google.com"); HttpURLConnection hpCon = (HttpURLConnection) hp.openConnection(); // Display request method. System.out.println("Request method is " + hpCon.getRequestMethod()); // Display response code. System.out.println("Response code is " + hpCon.getResponseCode()); // Display response message. System.out.println("Response Message is " + hpCon.getResponseMessage()); // Get a list of the header fields and a set // of the header keys. Map<String, List<String>> hdrMap = hpCon.getHeaderFields(); Set<String> hdrField = hdrMap.keySet(); System.out.println("\nHere is the header:"); // Display all header keys and values. for(String k : hdrField) { System.out.println("Key: " + k + " Value: " + hdrMap.get(k)); } } } Question is Why hpCon Object is declared in the following way? HttpURLConnection hpCon = (HttpURLConnection) hp.openConnection(); instead of declaring like this HttpURLConnection hpCon = new HttpURLConnection(); Author provided the following explanation. I cant understand Java provides a subclass of URLConnection that provides support for HTTP connections. This class is called HttpURLConnection. You obtain an HttpURLConnection in the same way just shown, by calling openConnection( ) on a URL object, but you must cast the result to HttpURLConnection. (Of course, you must make sure that you are actually opening an HTTP connection.) Once you have obtained a reference to an HttpURLConnection object, you can use any of the methods inherited from URLConnection

  Read the article

• Implementing a modern web application with Web API on top of old services

  - by Gaui

  My company has many WCF services which may or may not be replaced in the near future. The old web application is written in WebForms and communicates straight with these services via SOAP and returns DataTables. Now I am designing a new modern web application in a modern style, an AngularJS client which communicates with an ASP.NET Web API via JSON. The Web API then communicates with the WCF services via SOAP. In the future I want to let the Web API handle all requests and go straight to the database, but because the business logic implemented in the WCF services is complicated it's going to take some time to rewrite and replace it. Now to the problem: I'm trying to make it easy in the near future to replace the WCF services with some other data storage, e.g. another endpoint, database or whatever. I also want to make it easy to unit test the business logic. That's why I have structured the Web API with a repository layer and a service layer. The repository layer has a straight communication with the data storage (WCF service, database, or whatever) and the service layer then uses the repository (Dependency Injection) to get the data. It doesn't care where it gets the data from. Later on I can be in control and structure the data returned from the data storage (DataTable to POCO) and be able to test the logic in the service layer with some mock repository (using Dependency Injection). Below is some code to explain where I'm going with this. But my question is, does this all make sense? Am I making this overly complicated and could this be simplified in any way possible? Does this simplicity make this too complicated to maintain? My main goal is to make it as easy as possible to switch to another data storage later on, e.g. an ORM and be able to test the logic in the service layer. And because the majority of the business logic is implemented in these WCF services (and they return DataTables), I want to be in control of the data and the structure returned to the client. Any advice is greatly appreciated. Update 20/08/14 I created a repository factory, so services would all share repositories. Now it's easy to mock a repository, add it to the factory and create a provider using that factory. Any advice is much appreciated. I want to know if I'm making things more complicated than they should be. So it looks like this: 1. Repository Factory public class RepositoryFactory { private Dictionary<Type, IServiceRepository> repositories; public RepositoryFactory() { this.repositories = new Dictionary<Type, IServiceRepository>(); } public void AddRepository<T>(IServiceRepository repo) where T : class { if (this.repositories.ContainsKey(typeof(T))) { this.repositories.Remove(typeof(T)); } this.repositories.Add(typeof(T), repo); } public dynamic GetRepository<T>() { if (this.repositories.ContainsKey(typeof(T))) { return this.repositories[typeof(T)]; } throw new RepositoryNotFoundException("No repository found for " + typeof(T).Name); } } I'm not very fond of dynamic but I don't know how to retrieve that repository otherwise. 2. Repository and service // Service repository interface // All repository interfaces extend this public interface IServiceRepository { } // Invoice repository interface // Makes it easy to mock the repository later on public interface IInvoiceServiceRepository : IServiceRepository { List<Invoice> GetInvoices(); } // Invoice repository // Connects to some data storage to retrieve invoices public class InvoiceServiceRepository : IInvoiceServiceRepository { public List<Invoice> GetInvoices() { // Get the invoices from somewhere // This could be a WCF, a database, or whatever using(InvoiceServiceClient proxy = new InvoiceServiceClient()) { return proxy.GetInvoices(); } } } // Invoice service // Service that handles talking to a real or a mock repository public class InvoiceService { // Repository factory RepositoryFactory repoFactory; // Default constructor // Default connects to the real repository public InvoiceService(RepositoryFactory repo) { repoFactory = repo; } // Service function that gets all invoices from some repository (mock or real) public List<Invoice> GetInvoices() { // Query the repository return repoFactory.GetRepository<IInvoiceServiceRepository>().GetInvoices(); } }

  Read the article

• Is hashing of just "username + password" as safe as salted hashing

  - by randomA

  I want to hash "user + password". EDIT: prehashing "user" would be an improvement, so my question is also for hashing "hash(user) + password". If cross-site same user is a problem then the hashing changed to hashing "hash(serviceName + user) + password" From what I read about salted hash, using "user + password" as input to hash function will help us avoid problem with reverse hash table hacking. The same thing can be said about rainbow table. Any reason why this is not as good as salted hashing?

  Read the article

• Would this violate any copyright issues?

  - by Farhad

  I am currently publishing a paper on skin detection. However, I need to find the appropriate histogram bin size for each colorspace. I recently came upon a paper that published what it found to be the ideal bin size. The paper can be found at: http://www.inf.pucrs.br/~pinho/CG/Trabalhos/DetectaPele/Artigos/OPTIMUM%20COLOR%20SPACES%20FOR%20SKIN%20DETECTION.pdf. I am specifically talking about Table 1. If I cite the source, would it be okay for me to use data from the table? Note that I cannot contact the author of the paper.

  Read the article

• Battling Emacs Pinky?

  - by haziz

  My problem is not so much emacs pinky as much as having to work with multiple machines, across 3 operating systems, both desktop and laptop, with differing keyboard layouts and different locations for Ctrl and Alt\Meta keys so I often have to pause and think about where is the Ctrl key on this machine. How do you deal with varying keyboard layouts, between Mac keyboards (mostly the laptops) and PC keyboards (mostly 101 keys in my case, yes the original PC keyboard)? I have turned the Caps lock Key into a Ctrl key (losing the Caps lock function completely rather than swapping with Ctrl) on most of them but still find myself hunting for the original Ctrl labeled key most of the time. How do you deal with this keyboard confusion? Suggestions, ideas and feedback welcome.

  Read the article

• I need help with some terminology

  - by Christine

  I'm not a programmer; I'm a freelance writer and researcher. I have a client who'd looking for stats on certain "threats" to the apps market. One of them is cowboy coding. (I know what that means; that's not my question.) Specifically, he wants to see numbers regarding how many apps have failed/crashed/removed because of errors made by, in essence, sloppy coding. (I'm not here to debate the merits of cowboy coding, and whether or not it is sloppy; work with me here.) I've used every possible search term/phrase I can think of, but I can't find any hard numbers, just anecdotal evidence. Have any of you seen any reports that have this kind of data?

  Read the article

• Should certain math classes be required for a Computer Science degree?

  - by sunpech

  For a Computer Science (CS) degree at many colleges and universities, certain math courses are required: Calculus, Linear Algebra, and Discrete Mathematics are few examples. However, since I've started working in the real world as a software developer, I have yet to truly use some the knowledge I had at once acquired from taking those classes. Discrete Math might be the only exception. My questions: Should these math classes be required to obtain a computer science degree? Or would they be better served as electives? I'm challenging even that the certain math classes even help with required CS classes. For example, I never used linear algebra outside of the math class itself. I hear it's used in Computer Graphics, but I never took those classes-- yet linear algebra was required for a CS degree. I personally think it could be better served as an elective rather than requirement because it's more specific to a branch of CS rather than general CS. From a Slashdot post CS Profs Debate Role of Math In CS Education: 'For too long, we have taught computer science as an academic discipline (as though all of our students will go on to get PhDs and then become CS faculty members) even though for most of us, our students are overwhelmingly seeking careers in which they apply computer science.'

  Read the article

• Windows Mobile Interview Question Categories

  - by Ramesh Patel

  I need to set categories for interviewing candidates for Windows Mobile Development. Like for ASP.NET, we can have OOPS .NET Framework (CLR, BCL, MSIL etc) Javascript, jQuery Data Controls ADO.NET SQL Server For Windows Mobile, which are categories that should be included? Being specific to our current product, it has not UI and will run in background. Security is the first thing to take into account. It is a SPY kind of application that will keep track of user activity. It can be used by companies to monotor their employees.

  Read the article

• Data validation best practices: how can I better construct user feedback?

  - by Cory Larson

  Data validation, whether it be domain object, form, or any other type of input validation, could theoretically be part of any development effort, no matter its size or complexity. I sometimes find myself writing informational or error messages that might seem harsh or demanding to unsuspecting users, and frankly I feel like there must be a better way to describe the validation problem to the user. I know that this topic is subjective and argumentative. StackOverflow might not be the proper channel for diving into this subject, but like I've mentioned, we all run into this at some point or another. There are so many StackExchange sites now; if there is a better one, feel free to share! Basically, I'm looking for good resources on data validation and user feedback that results from it at a theoretical level. Topics and questions I'm interested in are: Content Should I be describing what the user did correctly or incorrectly, or simply what was expected? How much detail can the user read before they get annoyed? (e.g. Is "Username cannot exceed 20 characters." enough, or should it be described more fully, such as "The username cannot be empty, and must be at least 6 characters but cannot exceed 30 characters."?) Grammar How do I decide between phrases like "must not," "may not," or "cannot"? Delivery This can depend on the project, but how should the information be delivered to the user? Should it be obtrusive (e.g. JavaScript alerts) or friendly? Should they be displayed prominently? Immediately (i.e. without confirmation steps, etc.)? Logging Do you bother logging validation errors? Internationalization Some cultures prefer or better understand directness over subtlety and vice-versa (e.g. "Don't do that!" vs. "Please check what you've done."). How do I cater to the majority of users? I may edit this list as I think more about the topic, but I'm genuinely interest in proper user feedback techniques. I'm looking for things like research results, poll results, etc. I've developed and refined my own techniques over the years that users seem to be okay with, but I work in an environment where the users prefer to adapt to what you give them over speaking up about things they don't like. I'm interested in hearing your experiences in addition to any resources to which you may be able to point me.

  Read the article

• Manager/Container class vs static class methods

  - by Ben

  Suppose I a have a Widget class that is part of a framework used independently by many applications. I create Widget instances in many situations and their lifetimes vary. In addition to Widget's instance specified methods, I would like to be able to perform the follow class wide operations: Find a single Widget instance based on a unique id Iterate over the list of all Widgets Remove a widget from the set of all widgets In order support these operations, I have been considering two approaches: Container class - Create some container or manager class, WidgetContainer, which holds a list of all Widget instances, support iteration and provides methods for Widget addition, removal and lookup. For example in C#: public class WidgetContainer : IEnumerable<Widget { public void AddWidget(Widget); public Widget GetWidget(WidgetId id); public void RemoveWidget(WidgetId id); } Static class methods - Add static class methods to Widget. For example: public class Widget { public Widget(WidgetId id); public static Widget GetWidget(WidgetId id); public static void RemoveWidget(WidgetId id); public static IEnumerable<Widget AllWidgets(); } Using a container class has the added problem of how to access the container class. Make it a singleton?..yuck! Create some World object that provides access to all such container classes? I have seen many frameworks that use the container class approach, so what is the general consensus?

  Read the article

• How to become a professional web developer from a C/C++ programmer?

  - by user1050165

  I am new here. This is my first post on stackoverflow. I am currently a high school student and know how to use Pascal and C/C++ to take part in competitions such as the Informatics in Olympiad. I have learnt data structure and many algorithms to solve various kinds of problems. Now, I want to move on to become a web developer. However, I know web development is quite different from competitive programming. To make a web application, I have to master HTML, Database, Backend programming etc. But these are all look like separate pieces of information. I don't know where to start and what order should I follow. Anybody who can give a comprehensive list of learning points? I know there are HTML, Ruby on Rails, CSS and Javascript. What else? More importantly, can someone give a brief outline of their relationship? I hope I can get help from you asap. Thanks!

  Read the article

• Is sticking to one language on a particular project a good practice?

  - by Ans

  I'm developing a pipeline for processing text that will go into production. The question I keep asking myself is: should I stick to one language for the project when I'm looking for a tool to do a particular task (e.g. NLTK, PDFMiner, CLD, CRFsuite, etc.)? Or is it OK to mix and match languages on the project? So I pick the best tool regardless of what language it's written in (e.g. OpenNLP, ParsCit, poppler, CFR++, etc.) and warp (wrap) my code around it? Note, I am not asking about should a developer stick to just one language for their career.

  Read the article

• What Web Technology to use for web app?

  - by Chris

  Want to get the opinions of the people of Stack Overflow. I am creating a web application that ideally will have some sort of desktop notification. i would love to do this in HTML5 but cant as need it to run on IE 8 and below. I have looked a Flex but I'm not 100% sure how to achieve desktop notifications when running as a web app. Has anyone had this dilemma or even know of anything that would be the best fit? All opinions are welcome, will help me out a lot

  Read the article

• Increase application performance

  - by Prayos

  I'm writing a program for a company that will generate a daily report for them. All of the data that they use for this report is stored in a local SQLite database. For this report, the utilize pretty much every bit of the information in the database. So currently, when I query the datbase, I retrieve everything, and store the information in lists. Here's what I've got: using (var dataReader = _connection.Select(query)) { if (dataReader.HasRows) { while (dataReader.Read()) { _date.Add(Convert.ToDateTime(dataReader["date"])); _measured.Add(Convert.ToDouble(dataReader["measured_dist"])); _bit.Add(Convert.ToDouble(dataReader["bit_loc"])); _psi.Add(Convert.ToDouble(dataReader["pump_press"])); _time.Add(Convert.ToDateTime(dataReader["timestamp"])); _fob.Add(Convert.ToDouble(dataReader["force_on_bit"])); _torque.Add(Convert.ToDouble(dataReader["torque"])); _rpm.Add(Convert.ToDouble(dataReader["rpm"])); _pumpOneSpm.Add(Convert.ToDouble(dataReader["pump_1_strokes_pm"])); _pumpTwoSpm.Add(Convert.ToDouble(dataReader["pump_2_strokes_pm"])); _pullForce.Add(Convert.ToDouble(dataReader["pull_force"])); _gpm.Add(Convert.ToDouble(dataReader["flow"])); } } } I then utilize these lists for the calculations. Obviously, the more information that is in this database, the longer the initial query will take. I'm curious if there is a way to increase the performance of the query at all? Thanks for any and all help. EDIT One of the report rows is called Daily Drilling Hours. For this calculation, I use this method: // Retrieves the timestamps where measured depth == bit depth and PSI >= 50 public double CalculateDailyProjectDrillingHours(DateTime date) { var dailyTimeStamps = _time.Where((t, i) => _date[i].Equals(date) && _measured[i].Equals(_bit[i]) && _psi[i] >= 50).ToList(); return _dailyDrillingHours = Convert.ToDouble(Math.Round(TimeCalculations(dailyTimeStamps).TotalHours, 2, MidpointRounding.AwayFromZero)); } // Checks that the interval is less than 10, then adds the interval to the total time private static TimeSpan TimeCalculations(IList<DateTime> timeStamps) { var interval = new TimeSpan(0, 0, 10); var totalTime = new TimeSpan(); TimeSpan timeDifference; for (var j = 0; j < timeStamps.Count - 1; j++) { if (timeStamps[j + 1].Subtract(timeStamps[j]) <= interval) { timeDifference = timeStamps[j + 1].Subtract(timeStamps[j]); totalTime = totalTime.Add(timeDifference); } } return totalTime; }

  Read the article

• Test iPhone app on iPad mini?

  - by Devfly

  I have developed an iPhone app, right now I only need a device for testing. I have 300$, and two choices - second hand iPhone 4, or brand new iPad mini. The better choice obviously is the iPad, but is it sufficient for testing iPhone apps on? On the iPad, iPhone apps can run just fine in 2X mode, but are there any differences between the app performance on iPhone and iPad (except the chipset). Should I test my app on actual iPhone, or the iPad will suffice? My app is RSS reader, not some game, so I think everything will be fine with testing on iPad mini. If I buy the iPad I will find some friends iPhone 4/3gs running iOS 5.1 (because my app's deployment target is 5.1, and the iPad comes with 6.0), but of course I can't extensively test on this iPhone. Thank you!

  Read the article

• Where should I draw the line between unit tests and integration tests? Should they be separate?

  - by Earlz

  I have a small MVC framework I've been working on. It's code base definitely isn't big, but it's not longer just a couple of classes. I finally decided to take the plunge and start writing tests for it(yes, I know I should've been doing that all along, but it's API was super unstable up until now) Anyway, my plan is to make it extremely easy to test, including integration tests. An example integration test would go something along these lines: Fake HTTP request object - MVC framework - HTTP response object - check the response is correct Because this is all doable without any state or special tools(browser automation etc), I could actually do this with ease with regular unit test frameworks(I use NUnit). Now the big question. Where exactly should I draw the line between unit tests and integration tests? Should I only test one class at a time(as much as possible) with unit tests? Also, should integration tests be placed in the same testing project as my unit testing project?

  Read the article

• Reasons to Use a VM For Development

  - by George Stocker

  Background: I work at a start-up company, where one team uses Virtual Machines to connect to a remote server to do their development, and another team (the team I'm on) uses local IIS/SQL Server 2005/Visual Studio installations to conduct work. Team VM is located about 1000 miles from Team Non-VM, and the servers the VMs run off of are located near Team VM (Latency, for those that are wondering, is about 50ms). A person high in the company is pushing for Team Non-VM to use virtual machines for programming, development, and testing. The latter point we agree on -- we want Virtual Machines to test configurations and various aspects of the web application in a 'clean' state. The Problem: What we don't agree on is having developers using RDP to connect to a desktop remotely that contains Visual Studio, SQL Server, and IIS to do the same development we could do locally on our laptops. I've tried the VM set-up, and besides the color issue, there is a latency issue that is rather noticeable, not to mention that since we're a start-up, a good number of employees work from home on occasion with our work laptops, and this move would cut off the laptops. They'd be turned in. Reasons to Use Remote VMs for Development (Not Testing!): Here are the stated reasons that this person wants us to use VMs: They work for TeamVM. They keep the source code "safe". If we want to work from home, we could just use our home PCs. Licenses (I don't know what the argument is, only that it's been used). Reasons not to use Remote VMs for Development: Here are the stated reasons why we don't want to use VMs: We like working from home. We get a lot done on our own time. We're not going to use our Home PCs to do work related stuff. The Latency is noticeable. Support for the VMs (if they go down, or if we need a new VM) takes a while. We don't have administrative privileges on the VM, and are unable to change settings as needed. What I'm looking for from the community is this: What reasons would you give for not using VMs for development? Keep in mind these are remote VMs -- this isn't a VM running on a local desktop. It's using the laptop (or a desktop) as a thin client for a remote VM. Also, on the other side of the coin: Is there something we're missing that makes VMs more palatable for development? Edit: I think 'safe' is used in term of corporate espionage, or more correctly if the Laptop gets stolen, the person who stole would have access to our source code. The former (as we've pointed out, is always going to be a possibility -- companies stop that with litigation, there isn't a technical solution (so far as I can see)). The latter point is ( though I don't know its usefulness in a corporate scenario) mitigated by Truecrypt'ing the entire volume.

  Read the article

• how to follow python polymorphism standards with math functions

  - by krishnab

  So I am reading up on python in Mark Lutz's wonderful LEARNING PYTHON book. Mark makes a big deal about how part of the python development philosophy is polymorphism and that functions and code should rely on polymorphism and not do much type checking. However, I do a lot of math type programming and so the idea of polymorphism does not really seem to apply--I don't want to try and run a regression on a string or something. So I was wondering if there is something I am missing here. What are the applications of polymorphism when I am writing functions for math--or is type checking philosophically okay in this case.

  Read the article

< Previous Page | 94 95 96 97 98 99 100 101 102 103 104 105  | Next Page >