Search Results

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

Page 214/563 | < Previous Page | 210 211 212 213 214 215 216 217 218 219 220 221  | Next Page >

• MATLAB: Best fitness vs mean fitness, initial range

  - by Sa Ta

  Based on the example of Rastrigin's function. At the plot function, if I chose 'best fitness', on the same graph 'mean fitness' will also be plotted. I understand well about 'best fitness' whereby it plots the best function value in each generation versus iteration number. It will reach value zero after some times. I don't understand about 'mean fitness'in the graph plotted. What do those 'mean fitness' values mean? How does the 'mean fitness' graph help to understand Rastrigin's function? What are the meaning of the term initial population, initial score and initial range? I wish to have a better understanding of these terms. The default value for initial range is [0,1]. Does it mean that 0 is the lower bound (lb) and 1 is the upper bound (ub)? Do these values interfere with the lb and ub values I set in the constraints? I try to better understand about lb and ub. If my lb is 0 and ub is 5, does it mean that my final point values will be within 0 and 5? If I know the lb and ub for my problem is between 0 and 5, do I just set the initial range as [0,5] at all times and may I assume that this is the best option for initial range, and I need not try it with any other values?

  Read the article

• Using which technique does facebook and pininterest show images?

  - by manish

  If anybody has ever noticed that when you open a image in Facebook something like this happens:- suppose you are at your homepage on Facebook:- the URL is https://www.facebook.com/ now if you open a image it gets opened in new modal like window and URL changes to:- https://www.facebook.com/photo.php?fbid=10151125374887397&set=a.338008237396.161268.36922302396&type=1&theater As far as I know in any common case a modal overlay would have kept the url in the address bar the same , My question is how does facebook / pintrest achieve this behaviour of not re-loading the whole page but still achieving the change in the address bar. Is there any jquery or javascript plugin for this?

  Read the article

• Why does this static field always get initialized over-eagerly?

  - by TheSilverBullet

  I am looking at this excellent article from Jon Skeet. While executing the demo code, Jon Skeet says that we can expect three different kinds of behaviours. To quote that article: The runtime could decide to run the type initializer on loading the assembly to start with... Or perhaps it will run it when the static method is first run... Or even wait until the field is first accessed... When I try this out (on framework 4), I always get the first result. That is, the static method is initialized before the assembly is loaded. I have tried running this multiple times and get the same result. (I tried both the debug and release versions) Why is this so? Am I missing something?

  Read the article

• Is it recommended to use more than one language at a startup?

  - by GoofyBall

  I work for a mobile startup where, for historical reasons, our chosen language was C#. I was recently assigned to a small project to build a tool that would be used by us internally. When I explained my intention to use Python to build this tool I was heavily criticized for this because introducing new languages, and technologies (Debian, Apache, Python and Django) into our ecosystem would make it harder for other developers to maintain (because only two other people know more than one language besides C#). I countered that this project would take far longer to develop in C# (which I think is an inherent problem with the language/.NET framework) and that the project was small and designed to solve a very particular problem. Of course it is necessary that the ecosystem be as a homogeneous as possible but if your are developing tooling, infrastructure, and internal systems when there are better things to build them with than C# then you should consider using them. By using one language you exclude a lot of other great libraries and frameworks out there, and this case it was the difference between taking one week to build in Python as opposed to a month in C#. Do you think it is acceptable to understand and use only only one language at a startup or even a larger company? Am I perhaps being naive??

  Read the article

• Understanding the Java Ecosystem

  - by syrion

  I have traditionally had the "luxury" of being a one-man development team. I've used Python extensively, have a reasonable command of Perl, PHP, and JavaScript. My problem is Java. I can write Java code. I'm not great at it--unlike Python, I rarely make use of anything unique to Java when I'm writing it. Furthermore, my experience is mostly in simple GUI/console programming. Unfortunately, I'm currently pursuing an IT degree where Java is the lingua franca. My database class is requiring that our projects be written in Java using servlets, and I just can't wrap my head around the ecosystem. Is there a good online overview of or tutorial on how the Java web ecosystem works? I have Thinking in Java, but it's mostly just the language itself (which I understand well enough to get by). I have looked at the Sun servlet tutorial, but it seems outdated.

  Read the article

• Need explanation of hexagonal architecture

  - by Victor Grazi

  I am reading about Alistair Cockburn's Hexagonal Architecture http://alistair.cockburn.us/Hexagonal+architecture with interest. One claim he makes is: "Finally, the automated function regression tests detect any violation of the promise to keep business logic out of the presentation layer. The organization can detect, and then correct, the logic leak." I do not understand this point. Is he saying that because the test is headless, then calls to a ui layer will throw exceptions? That doesn't seem to be a very sound test!

  Read the article

• What are the steps to grouping related classes into packages

  - by user2368481

  I've been googling this for some time, but what I haven't found are the clear steps needed to be taken to group related classes into packages in Java. In my case, I have about a number of .java files that I'd like to group into 3 packages according to the MVC pattern. One package for Model classes, one package for View classes and one package for Controller classes. I've identified which belong in what package, but not sure of the next step.

  Read the article

• In a SSL web application, what would be the vulnerabilities of using session based authentication?

  - by Thomas C. G. de Vilhena

  I'm not sure the term even exists, so let me explain what I mean by "session based authentication" through some pseudo-code: void PerformLogin(string userName, string password) { if(AreValidCredentials(userName, password)) { Session.Set("IsAuthenticated", true); } else { Message.Show("Invalid credentials!"); } } So the above method simply verifies the provided credentials are valid and then sets a session flag to indicate that the session user is authenticated. Under plain HTTP that is obviously unsafe, because anyone could hijack the session cookie/querystring and breach security. However, under HTTPS the session cookie/querystring is protected because client-server communication is encrypted, so I believe this authentication approach would be safe, wouldn't it? I'm asking this because I want to know how authentication tickets can improve web applications security. Thanks in advance!

  Read the article

• Liskov principle: violation by type-hinting

  - by Elias Van Ootegem

  According to the Liskov principle, a construction like the one below is invalid, as it strengthens a pre-condition. I know the example is pointless/nonsense, but when I last asked a question like this, and used a more elaborate code sample, it seemed to distract people too much from the actual question. //Data models abstract class Argument { protected $value = null; public function getValue() { return $this->value; } abstract public function setValue($val); } class Numeric extends Argument { public function setValue($val) { $this->value = $val + 0;//coerce to number return $this; } } //used here: abstract class Output { public function printValue(Argument $arg) { echo $this->format($arg); return $this; } abstract public function format(Argument $arg); } class OutputNumeric extends Output { public function format(Numeric $arg)//<-- VIOLATION! { $format = is_float($arg->getValue()) ? '%.3f' : '%d'; return sprintf($format, $arg->getValue()); } } My question is this: Why would this kind of "violation" be considered harmful? So much so that some languages, like the one I used in this example (PHP), don't even allow this? I'm not allowed to strengthen the type-hint of an abstract method but, by overriding the printValue method, I am allowed to write: class OutputNumeric extends Output { final public function printValue(Numeric $arg) { echo $this->format($arg); } public function format(Argument $arg) { $format = is_float($arg->getValue()) ? '%.3f' : '%d'; return sprintf($format, $arg->getValue()); } } But this would imply repeating myself for each and every child of Output, and makes my objects harder to reuse. I understand why the Liskov principle exists, don't get me wrong, but I find it somewhat difficult to fathom why the signature of an abstract method in an abstract class has to be adhered to so much stricter than a non-abstract method. Could someone explain to me why I'm not allowed to hind at a child class, in a child class? The way I see it, the child class OutputNumeric is a specific use-case of Output, and thus might need a specific instance of Argument, namely Numeric. Is it really so wrong of me to write code like this?

  Read the article

• Using PHP version 5.2 or 5.3 for end-user commercial products?

  - by Ash

  I'm doing research on what version of PHP to use when creating commercial scripts that will be sold to end users. Although the available stats aren't great, PHP 5.3 shows a 18.5% adoption rate. I'd like to use Symfony to create these scripts and it requires 5.3.2 which shows an even lower adoption rate (roughly 13% of that 18.5% use less than 5.3.2). Would I be risking much by jumping straight to PHP 5.3.2+ or should I ignore the stats and plough ahead?

  Read the article

• Limited resource practice problems?

  - by Mark

  I'm applying for some big companies and the areas I seem to be getting burned on is problems involving limited memory, disk-space or throughput. These large companies process GBs of data every second (or more), and they need efficient ways of managing all that data. I have no experience with this as none of the projects I have worked on have grown that large. Is there a good place to learn about or practice these sorts of problems? Most of the practice-problem sites I've encountered only have problems where you have to solve something efficiently (usually involving prime numbers) but none of them limit your resources.

  Read the article

• Sending an email with attachment from server side

  - by SaravananArumugam

  I have to create a word document in a specific format and send it as attachment to some email addresses. I have a preview screen for the report which on approval has to be send in email. This is an ASP.NET MVC 3 application. I am left with a few options here. I am creating the preview using html. I can convert this html into doc and send it, which would be a straight solution. But capturing the Response object's output is being a tough job. I thought of using Mail merge functionality of MS word, where I'll be filling the placeholders of the doc template. But the problem is conceptually, it doesn't appear to be mail merge. I have found someone suggesting to use RTF format and replace the placeholders with database values. Which is the right thing to do? What's the best solution here? Is there any other option than the three listed above?

  Read the article

• Finding Database issue for iphone app

  - by David Liu

  I know this is a dumb question and it might not be "conceptual" but, as a self-starter I really want to know how to get connected to some sort of "commercial database"? I'm recently designing my local gas station utility app for iphone and ipad. I have absolutely no clue of find a relevant database. For example, if I want to make an app for pizza ordering in the great Chicago area. How do I get info (price, menu, location, etc.) of those pizza stores scattered all over Chicago? Can any one light something for me? I appreciated your help. **If this question is not suitable here please tell me and I will delete this post. Thank you.

  Read the article

• How Microsoft Market DotNet?

  - by Fendy

  I just read an Joel's article about Microsoft's breaking change (non-backwards compatibility) with dot net's introduction. It is interesting and explicitly reflected the condition during that time. But now almost 10 years has passed. The breaking change It is mainly on how bad is Microsoft introducing non-backwards compatibility development tools, such as dot net, instead of improving the already-widely used asp classic or VB6. As much have known, dot net is not natively embedded in windows XP (yes in vista or 7), so in order to use the .net apps, you need to install the .net framework of over 300mb (it's big that day). However, as we see that nowadays many business use .net as their main development tools, with asp.net or mvc as their web-based applications. C# nowadays be one of tops programming languages (the most questions in stackoverflow). The more interesing part is, win32api still alive even there is newer technology out there (and still widely used). Imagine if microsoft does not introduce the breaking change, there will many corporates still uses asp classic or vb-based applications (there still is, but not that much). There are many corporates use additional services such as azure or sharepoint (beside how expensive is it). Please note that I also know there are many flagships applications (maybe adobe's and blizzard's) still use C-based or older language and not porting to newer high-level language. The question How can Microsoft persuade the users to migrate their old applications into dot net? As we have known it is very hard and give no immediate value when rewrite the applications (netscape story), and it is very risky. I am more interested in Microsoft's way and not opinion such as "because dot net is OOP, or dot net is dll-embedable, etc". This question may be constructive, as the technology is vastly changes over times lately. As we can see, Microsoft changes Asp.Net webform to MVC, winform is legacy now, it is starting to change to use windows store rather than basic-installment, touchscreen and later on we will have see-through applications such as google class. And that will be breaking changes. We will need to account portability as an issue nowadays. We will need other than just mere technology choice, but also migration plans. Even maybe as critical as we might need multiplatform language compiler, as approached by Joel's Wasabi. (hey, I read his articles too much!)

  Read the article

• Do I really need to learn Python? [closed]

  - by Pouya

  These days, I see the name "Python" a lot. Mostly when I'm doing some programming on linux/mac, I see a trace of Python. I have a fair knowledge of C++ and I'm quite good at Java. I also know Delphi which comes handy sometimes. I've been good with these languages, however, I was wondering if learning Python could make it better. What does it offer that makes it worth learning? What are its key/unique advantages/features?

  Read the article

• Do you develop with localization in mind?

  - by Jimmy C

  When working on a software project or a website, do you develop with localization in mind? By this I mean e.g. Externalizing all strings, including error messages. Not using images that contain text. Designing your UI with text expansion in mind. Using pseudo-translation to test your UI's early in the process. etc. On projects you work on, are these in the 'nice to have' category and let the L10N team worry about the rest, or do you have localization readiness built into your development process? I'm interested to hear how developers view localization in general.

  Read the article

• Developing a new complex travel website

  - by Kay

  We need to develop a completely new website for customers to choose a travel product with a contract. It needs to interface to our inventory to take the conference facility, hotel rooms etc. out of inventory once a contract has been signed (e-signature) and deposit paid. If you were starting from scratch, would you in-house or contract? If in-house, what development tools should I evaluate primarily - sharepoint, ASP.net? We are a small IT shop but we could hire 1-2 developers for this. We need to get something up in 12-18 months.

  Read the article

• Simplifying C++11 optimal parameter passing when a copy is needed

  - by Mr.C64

  It seems to me that in C++11 lots of attention was made to simplify returning values from functions and methods, i.e.: with move semantics it's possible to simply return heavy-to-copy but cheap-to-move values (while in C++98/03 the general guideline was to use output parameters via non-const references or pointers), e.g.: // C++11 style vector<string> MakeAVeryBigStringList(); // C++98/03 style void MakeAVeryBigStringList(vector<string>& result); On the other side, it seems to me that more work should be done on input parameter passing, in particular when a copy of an input parameter is needed, e.g. in constructors and setters. My understanding is that the best technique in this case is to use templates and std::forward<>, e.g. (following the pattern of this answer on C++11 optimal parameter passing): class Person { std::string m_name; public: template <class T, class = typename std::enable_if < std::is_constructible<std::string, T>::value >::type> explicit Person(T&& name) : m_name(std::forward<T>(name)) { } ... }; A similar code could be written for setters. Frankly, this code seems boilerplate and complex, and doesn't scale up well when there are more parameters (e.g. if a surname attribute is added to the above class). Would it be possible to add a new feature to C++11 to simplify code like this (just like lambdas simplify C++98/03 code with functors in several cases)? I was thinking of a syntax with some special character, like @ (since introducing a &&& in addition to && would be too much typing :) e.g.: class Person { std::string m_name; public: /* Simplified syntax to produce boilerplate code like this: template <class T, class = typename std::enable_if < std::is_constructible<std::string, T>::value >::type> */ explicit Person(std::string@ name) : m_name(name) // implicit std::forward as well { } ... }; This would be very convenient also for more complex cases involving more parameters, e.g. Person(std::string@ name, std::string@ surname) : m_name(name), m_surname(surname) { } Would it be possible to add a simplified convenient syntax like this in C++? What would be the downsides of such a syntax?

  Read the article

• How vibrations might effect Kinect depth measurements

  - by dreza

  I'm currently doing some research into development with the Microsoft Kinect product. My project manager has come up with a potential design for mounting the camera to do the capturing. However the solution means that the camera might be subject to vibrations as the platform it is on is directly connected to where the subjects will be moving. It was my thought that vibrations would effect the quality of the results, however I could not come up with a viable explanation as to why, other than it's the same as if you held a camera in your hand and your hand was shaking vs using a tripod. Do vibrations effect the depth measurements on a Kinect and if so how can I explain this in simple terms to my PM to help come up with a better design to attach the sensor to?

  Read the article

• Can "go" replace C++? [closed]

  - by iammilind

  I was reading wiki article about "go" programming language, where Bruce Eckel states: The complexity of C++ (even more complexity has been added in the new C++), and the resulting impact on productivity, is no longer justified. All the hoops that the C++ programmer had to jump through in order to use a C-compatible language make no sense anymore --they're just a waste of time and effort. Now, Go makes much more sense for the class of problems that C++ was originally intended to solve. Can go really replace C++(11) for new development in future? How about generic programming? I don't know go , but the amount of time (in)wasted in learning C++ seems to go in vain.

  Read the article

• What are the standard practices for database access in .net?

  - by Gulshan

  I have seen weird database access practices in .net. I have seen stored procedures for every database tasks. I have seen every database property name is preceded by it's table name. I have seen fully separate layer/.dll for very few or no business logic. I have seen along with ORMs, there are separate data access layer playing the same role. And with them, I have always heard- "These are the standards you have to maintain". So, what are the real standards for data access in .net? What are the rules you follow?

  Read the article

• Creating an expandable, cross-platform compatible program "core".

  - by Thomas Clayson

  Hi there. Basically the brief is relatively simple. We need to create a program core. An engine that will power all sorts of programs with a large number of distinct potential applications and deployments. The core will be an analytics and algorithmic processor which will essentially take user-specific input and output scenarios based on the information it gets, whilst recording this information for reporting. It needs to be cross platform compatible. Something that can have platform specific layers put on top which can interface with the core. It also needs to be able to be expandable, for instance, modular with developers being able to write "add-ons" or "extensions" which can alter the function of the end program and can use the core to its full extent. (For instance, a good example of what I'm looking to create is a browser. It has its main core, the web-kit engine, for instance, and then on top of this is has a platform-specific GUI and can also have add-ons and extensions which can change the behavior of the program.) Our problem is that the extensions need to interface directly with the main core and expand/alter that functionality rather than the platform specific "layer". So, given that I have no experience in this whatsoever (I have a PHP background and recently objective-c), where should I start, and is there any knowledge/wisdom you can impart on me please? Thanks for all the help and advice you can give me. :) If you need any more explanation just ask. At the moment its in the very early stages of development, so we're just researching all possible routes of development. Thanks a lot

  Read the article

• Web development tools/approaches?

  - by Clinton

  My day job involves a bit of programming, but I've recently been attempting some web development for personal reasons. I've got Drupal up and running and done basic things like add new content (i.e. heading and text) and add modules and themes, but I'm not sure how to approach actually designing pages. When I mucked around with webpages 15 years ago, it was just a mixture of HTML, CSS and Javascript, generally written with a text editor. Have things changed, or is this the way I'd make a Drupal page today? If it makes a difference, in my case the page's I want to design simply have static content, but I'd like them to be easily updatable.

  Read the article

• How do you put a database online?

  - by Dezrik

  I have a very beginner question regarding web development. I've had some experience with JSP, Hibernate, and MAMP to create a simple system for tracking inventory and sales. But this was all done locally on one computer. This time, I want to create a system that could be accessible online. It's to help my mother track her business wherever she goes. So there would be similar aspects like tracking inventory and sales. I understand that you have to have a server in which to host all the files in. But I don't understand how you can access your database online. Or what sorts of applications or products should be used. Currently the host of my database is localhost. How do put it online such that you can still do CRUD operations? Are there any guides to do this?

  Read the article

• Is committing/checking code everyday a good practice?

  - by ArtB

  I've been reading Martin Fowler's note on Continuous Integration and he lists as a must "Everyone Commits To the Mainline Every Day". I do not like to commit code unless the section I'm working on is complete and that in practice I commit my code every three days: one day to investigate/reproduce the task and make some preliminary changes, a second day to complete the changes, and a third day to write the tests and clean it up^ for submission. I would not feel comfortable submitting the code sooner. Now, I pull changes from the repository and integrate them locally usually twice a day, but I do not commit that often unless I can carve out a smaller piece of work. Question: is committing everyday such a good practice that I should change my workflow to accomodate it, or it is not that advisable? ^ The order is more arbitrary and depends on the task, my point was to illustrate the time span and activities, not the exact sequence.

  Read the article

< Previous Page | 210 211 212 213 214 215 216 217 218 219 220 221  | Next Page >