Search Results

Search found 113970 results on 4559 pages for 'source code control'.

Page 116/4559 | < Previous Page | 112 113 114 115 116 117 118 119 120 121 122 123  | Next Page >

  • Can I distribute my MATLAB program as open source?

    - by yuk
    I know, the general answer will be yes, but here is my situation. I got a plotting function from one MATLAB's toolbox and modified its m-file to draw what I need. Eventually this function became a part of program I would like to distribute as an open source (or under other license). Can I do this? Well, may be it was not wise to create a function in such a way, but I didn't think about distribution at that time. The function still depends on other functions in this toolbox, so a potential user supposed to have a license for it. Any thoughts, recommendations? Have you ever modified MATLAB's m-files directly?

    Read the article

  • Is there a C# open-source search app which scales cheaply?

    - by domspurling
    I need to quickly replace a listings website which has the following characteristics: smallish database (10,000 items, < 1GB) < 10% of the items updated/created/removed daily most common activity is searching the whole dataset, returning 1-1000 items traffic peaks at 1m page impressions per day Scaling strategy for the existing app has been to separate read-only and read/write activity. Multiple slave databases are used for searching and writes are done to a master, which update the slaves using MS SQL replication. Since read activity is more common than write, this has proved to be a cheap way to do database load balancing, without true clustering. I now need to replace the app - are there any C# open-source apps which scale as neatly as this?

    Read the article

  • Pure Java open-source libraries for portfolio selection (= constrained, non-linear optimization)?

    - by __roland__
    Does anyone know or has experience with a pure Java library to select portfolios or do some similar kinds of quadratic programming with constraints? There seems to be a lot of tools, as already discussed elsewhere - but what I would like to use is a pure Java implementation. Since I want to call the library from within another open-source software with a BSD-ish license I would prefer LGPL over GPL. Any help is appreciated. If you don't know such libraries, which is the most simple algorithm you would suggest to implement? It has to cope with an inequality constraint (all x_i = 0) and an equality constraint (sum of all x_i = 1).

    Read the article

  • flash player embedded in asp page which is opened in webbrowser control in .NET access through windo

    - by Prit
    I am develoing a windows application in C#.NET. In one of my winform I have added a WebBrowser control. In this webbrowser control I have opened an asp page from my local website. Now in this webpage there is one flash object which is used to play swf files. Now my question is can I access this control from my winform? If so then how? can u create a handler for that flash object?

    Read the article

  • How can I isolate the form controls in a ASP Web User Control from the rest of the page's form contr

    - by Justin808
    I have a Web User Control I created for authentication. The web user control is inside the box below. Clicking any button (1 or 2) below works correct as it goes to the correct c# button click event in the code behind file. If I press enter on fields a or b it goes to the correct callback (button1's) if I press enter on field c it still goes to button1's callback, not button2's How can I give my web user control a nice self contained for and view state etc, so it wont mess with the remainder of the page's form? +--------------+ | User: __a___ | | Pass: __b___ | | [button1]| +--------------+ Prompt:______c______ [button2]

    Read the article

  • What are appropriate assembly attribute values for an open source (LGPL) project?

    - by michielvoo
    I have just started working on an open source project. The project is hosted on CodePlex and I work on it in my spare time. What would be appropriate values for the default assembly attributes (listed below)? [assembly: AssemblyCompany("")] [assembly: AssemblyCopyright("")] [assembly: AssemblyTrademark("")] It surprised me to see the AssemblyCompany and AssemblyCopyright attributes on several projects (on CodePlex as well as Google Code): xUnit.net [assembly: AssemblyCopyright("Copyright (C) Microsoft Corporation")] [assembly: AssemblyCompany("Microsoft Corporation")] DotNetNuke: <Assembly: AssemblyCompany("DotNetNuke Corporation")> <Assembly: AssemblyCopyright("DotNetNuke is copyright 2002-2010 by DotNetNuke Corporation. All Rights Reserved.")> Moq: [assembly: AssemblyCompany("Clarius Consulting, Manas Technology Solutions, InSTEDD")]

    Read the article

  • Why avoid pessimistic locking in a version control system?

    - by raven
    Based on a few posts I've read concerning version control, it seems people think pessimistic locking in a version control system is a bad thing. Why? I understand that it prevents one developer from submitting a change while another has the file checked out, but so what? If your code files are so big that you constantly have more than one person working on them at the same time, I submit that you should reorganize your code. Break it up into smaller functional units. Integration of concurrent code changes is a tedious and error-prone process even with the tools a good version control system provides to make it easier. I think it should be avoided if at all possible. So, why is pessimistic locking discouraged?

    Read the article

  • How to Deploy my Open Source Projects using Maven's Central Repository?

    - by sfussenegger
    Is there anything I could do to get my own open source stuff into Maven's Central repository? I've wondered many times how I could get my own projects into Maven's Central repository. I was asking this myself, especially as I've seen some well known projects hosting their own repository, requiring users to add dependency and repository. At the same time, it's getting difficult for other projects to depend on those projects. As I neither want others to add an additional repository nor to host one myself, I'm looking for other ways. And why aren't some projects using the option to deploy to Maven Central in favor of their self-hosted repository? Any good reasons that aren't obvious?

    Read the article

  • How to integrate access control with my ORM in a .net windows form application?

    - by Ying
    I am developing a general database query tools, a .Net 3.5 Windows Form application. In order to make the presentation layer is independent of the database layer. I use an ORM framework, XPO from DevExpress. But, I have no access control function built in. I surfed Internet and I found in WCF Data Services, there is an interesting concept, Interceptor, which is following AOP(Aspect Oriented Programming). I am wondering who has such an experience to build access control in ORM. My basic requirement is : It should be a general method and controlled by users in runtime. So any hard coding is not acceptable. It could be based on attribute, database table, or even an external assembly. I am willing to buy a ready solution. According to the idea of AOP, an access control function can be integrated with existing functions easily and nearly not knowingly to the previous developer;) Any suggestions are welcome.

    Read the article

  • Why do Java source files go into a directory structure?

    - by bdhar
    Suppose that I am creating a Java project with the following classes com.bharani.ClassOne com.bharani.ClassTwo com.bharani.helper.HelperOne com.bharani.helper.support.HelperTwo with files put immediately under the folder 'src' src/ClassOne.java src/ClassTwo.java src/HelperOne.java src/HelperTwo.java and compile them using the command $ javac src/*.java -d classes (assuming that classes directory exists) The compiler compiles these files and put the class files in appropriate sub-directories inside the 'classes' directory like this classes/com/bharani/ClassOne.class classes/com/bharani/ClassTwo.class classes/com/bharani/helper/HelperOne.class classes/com/bharani/helper/support/HelperTwo.class Because the spec mandates that the classes should go inside appropriate directory structure. Fine. My question is this: When I use an IDE such as Eclipse or NetBeans, they create the directory structure for the source code directory ('src' directory here) also. Why is that? Is it mandatory? Or, is it just a convention? Thanks.

    Read the article

  • Where can I find a deliberately insecure open source web application?

    - by Phil Laliberte
    As a developer, I've learned that I usually gain a better understanding of best/worst practices through experience. The area of web application security isn't really somewhere where my organization can afford to let developers learn through trial and error. So looking for a hands-on approach to knowledge sharing of best practices in web application security, I was thinking that it would be useful to have an open source application that was deliberately built to be insecure in order to help teach junior developers about application security. Does anyone out there know where to find something like this?

    Read the article

  • Print new line in the source-code with jQuery.

    - by Kucebe
    I have a simple function in jQuery that creates new elements in the DOM. the problem is in the html source code, it append every element in the same line, and it's very bad to read. function _loadNewElements(elements){ for(var i=0; i<elements.length; i++){ var fixedElement = $('<img />') var position = elements[i].position; var cssMap = { 'position': 'fixed', 'top': position.top + "px", 'left': position.left + "px" }; fixedElement.css(cssMap); fixedElement.addClass("fixedTag"); fixedElement.attr('alt', elements[i].text); fixedElement.attr('src', "elements/" + elements[i].id + ".png"); fixedElement.appendTo($('#board')); //i'd like to print something here like ("\n"); } } I tried document.write("\n") but in this context it doesn't work. Any solution?

    Read the article

  • How Much Does Source Code Cost? Range?

    - by Brain Freeze
    I have taken a job selling a customized "online workplace management application." Our clients' businesses work around the application. Our clients track their time (which is how they get paid), finances and work documents through the application we provide and give their clients access to their interests throught the application. Our clients range from 2 users to 500 users. Each user probably processes 200 files per year and generates a fee for each file in the range of $500-$2500 per file. The application has been refined over a period of years and has cost around a million to develop. Does anyone know what range something like this sells for (source code, add-ons such as support and hosting)? I am trying to wrap my head around it as my background is not in software development.

    Read the article

  • How to automatically check out a database file in a source controlled web application ?

    - by TheRHCP
    Hello, I am working on an ASP.NET web application, we are a small team (4 students) and we do not have access to a dedicated server to host the database instance. So for this web application we decided just to put the database file in the App_Data folder. The problem is that our project is source controled on TFS, so every time you open the solution and try to launch the web application, we get an expcetion saying that database is read-only. That is logical because the databse file is not automatically checked-out. Is there a workaround to avoid a manual check-out of the database file everytime we open the solution ? Thanks.

    Read the article

  • Will a source-removal sort always return a maximal cycle?

    - by Jason Baker
    I wrote a source-removal algorithm to sort some dependencies between tables in our database, and it turns out we have a cycle. For simplicity, let's say we have tables A, B, C, and D. The edges are like this: (A, B) (B, A) (B, C) (C, D) (D, A) As you can see, there are two cycles here. One is between A and B and another is between all four of them. Will this type of sort always choke on the largest cycle? Or is that not necessarily the case?

    Read the article

  • Is there a generic open-source reporting system out there?

    - by syntactico
    I recently started a position at a new company, and one of the first projects they want is an internal reporting system that points at database A, B, C and reports various metrics/statistics/predictions. Basically, the same thing I've done or worked on and every company I've ever been hired by. Since this gets a bit boring after a while, I was wondering if there already exists some sort of open-source package that accomplishes this goal. Ideally, it would work with multiple databases out-of-box (PostgreSQL, MySQL, MSSQL, Oracle minimally), determine relationships between tables (either automatically from their schemas, or allow you to manually set them up after pooling all the tables), allow you to create reports based on a subset of tables, customizing what data you wanted to be displayed/calculated (I suppose this would be challenging since you've no idea what every audience wants, and would need to make this flexible) I'm debating making something like this in my spare time if one does not already exist. Just curious.

    Read the article

  • Cannot step into .NET framework source with VS2008 SP1.

    - by Vilx-
    Somehow my VS2008 SP1 has lost the ability to step into .NET framework sources. I've played around with checkboxes to no end; I've re-deleted the Symbol cache folder a dozen times; and I've tried all kinds of debug symbol servers. All it does is download some .PDB files, but when I try to select a stack frame in .NET, I always get the message about no source available and "do you want to view disassembly". What gives? Added: Web application; Windows Vista Business x32; .NET 3.5 SP1.

    Read the article

  • What open source C/C++ audio compression options are there besides LAME MP3?

    - by Ole Jak
    Are there any C/C++ open source audio encoder besides LAME MP3? It doesn't need to be exactly mp3 format, I need a "compressed digital audio file". I do not want to use Lame because it is too big while no programmer can answer a simple question on it (share simple but easily downloadable and readable project containing only needed 2 simple functions... So I'm tired of searching for help with it.. I need something fresh powerful but more readable than this lib I found (mp3stego) ) "I don't want LAME because I am a fighter with its monopoly" Haha..

    Read the article

  • How to get the set events of a control?

    - by Jack
    It's possible via C# code get an list of methods/delegates that was set to Control? let me explain better.. For example. Assuming some definitions like this: foo.Click += (a, b) => { ... } //.. foo.Click += (A,B) => { ... } And a megic method: var baa = foo.GetEvents("Click"); Returns baa[0] points to (a, b) => { ... } baa[1] points to (A,B) => { ... } My scenery: I make and add dynamically event to some controls inside a loop. I want depending to a boolean value a event of control of index one,will removed by using control.Click -= baa[1] or something like this. I hope this is clear for your. Thanks in advance.

    Read the article

  • My company is a Rackspace Cloud client (provided to us for free) and I'm trying to find some way to set up version control

    - by Nick S.
    As the title says, my (small) business is provided a free Rackspace Cloud client account. We receive a decent amount of traffic but I haven't been able to put together a business case to move to our own server yet. However, we are developing some complex apps and I'm frustrated with not having the ability to even ssh into the remote server. Ultimately, I'd like to set up some sort of version control (at this point, I'll take anything, git or otherwise). I have control over databases, can FTP, set up cron jobs, and perform a few other basic functions. I can't think of any way to set up git or something similar without ssh access. A thought went through my mind that maybe some sort of PHP version control exists that I might be able to set up, but I haven't had any luck finding it yet. Do you guys have any ideas, thoughts, or advice?

    Read the article

  • HTG Reviews the CODE Keyboard: Old School Construction Meets Modern Amenities

    - by Jason Fitzpatrick
    There’s nothing quite as satisfying as the smooth and crisp action of a well built keyboard. If you’re tired of  mushy keys and cheap feeling keyboards, a well-constructed mechanical keyboard is a welcome respite from the $10 keyboard that came with your computer. Read on as we put the CODE mechanical keyboard through the paces. What is the CODE Keyboard? The CODE keyboard is a collaboration between manufacturer WASD Keyboards and Jeff Atwood of Coding Horror (the guy behind the Stack Exchange network and Discourse forum software). Atwood’s focus was incorporating the best of traditional mechanical keyboards and the best of modern keyboard usability improvements. In his own words: The world is awash in terrible, crappy, no name how-cheap-can-we-make-it keyboards. There are a few dozen better mechanical keyboard options out there. I’ve owned and used at least six different expensive mechanical keyboards, but I wasn’t satisfied with any of them, either: they didn’t have backlighting, were ugly, had terrible design, or were missing basic functions like media keys. That’s why I originally contacted Weyman Kwong of WASD Keyboards way back in early 2012. I told him that the state of keyboards was unacceptable to me as a geek, and I proposed a partnership wherein I was willing to work with him to do whatever it takes to produce a truly great mechanical keyboard. Even the ardent skeptic who questions whether Atwood has indeed created a truly great mechanical keyboard certainly can’t argue with the position he starts from: there are so many agonizingly crappy keyboards out there. Even worse, in our opinion, is that unless you’re a typist of a certain vintage there’s a good chance you’ve never actually typed on a really nice keyboard. Those that didn’t start using computers until the mid-to-late 1990s most likely have always typed on modern mushy-key keyboards and never known the joy of typing on a really responsive and crisp mechanical keyboard. Is our preference for and love of mechanical keyboards shining through here? Good. We’re not even going to try and hide it. So where does the CODE keyboard stack up in pantheon of keyboards? Read on as we walk you through the simple setup and our experience using the CODE. Setting Up the CODE Keyboard Although the setup of the CODE keyboard is essentially plug and play, there are two distinct setup steps that you likely haven’t had to perform on a previous keyboard. Both highlight the degree of care put into the keyboard and the amount of customization available. Inside the box you’ll find the keyboard, a micro USB cable, a USB-to-PS2 adapter, and a tool which you may be unfamiliar with: a key puller. We’ll return to the key puller in a moment. Unlike the majority of keyboards on the market, the cord isn’t permanently affixed to the keyboard. What does this mean for you? Aside from the obvious need to plug it in yourself, it makes it dead simple to repair your own keyboard cord if it gets attacked by a pet, mangled in a mechanism on your desk, or otherwise damaged. It also makes it easy to take advantage of the cable routing channels in on the underside of the keyboard to  route your cable exactly where you want it. While we’re staring at the underside of the keyboard, check out those beefy rubber feet. By peripherals standards they’re huge (and there is six instead of the usual four). Once you plunk the keyboard down where you want it, it might as well be glued down the rubber feet work so well. After you’ve secured the cable and adjusted it to your liking, there is one more task  before plug the keyboard into the computer. On the bottom left-hand side of the keyboard, you’ll find a small recess in the plastic with some dip switches inside: The dip switches are there to switch hardware functions for various operating systems, keyboard layouts, and to enable/disable function keys. By toggling the dip switches you can change the keyboard from QWERTY mode to Dvorak mode and Colemak mode, the two most popular alternative keyboard configurations. You can also use the switches to enable Mac-functionality (for Command/Option keys). One of our favorite little toggles is the SW3 dip switch: you can disable the Caps Lock key; goodbye accidentally pressing Caps when you mean to press Shift. You can review the entire dip switch configuration chart here. The quick-start for Windows users is simple: double check that all the switches are in the off position (as seen in the photo above) and then simply toggle SW6 on to enable the media and backlighting function keys (this turns the menu key on the keyboard into a function key as typically found on laptop keyboards). After adjusting the dip switches to your liking, plug the keyboard into an open USB port on your computer (or into your PS/2 port using the included adapter). Design, Layout, and Backlighting The CODE keyboard comes in two flavors, a traditional 87-key layout (no number pad) and a traditional 104-key layout (number pad on the right hand side). We identify the layout as traditional because, despite some modern trapping and sneaky shortcuts, the actual form factor of the keyboard from the shape of the keys to the spacing and position is as classic as it comes. You won’t have to learn a new keyboard layout and spend weeks conditioning yourself to a smaller than normal backspace key or a PgUp/PgDn pair in an unconventional location. Just because the keyboard is very conventional in layout, however, doesn’t mean you’ll be missing modern amenities like media-control keys. The following additional functions are hidden in the F11, F12, Pause button, and the 2×6 grid formed by the Insert and Delete rows: keyboard illumination brightness, keyboard illumination on/off, mute, and then the typical play/pause, forward/backward, stop, and volume +/- in Insert and Delete rows, respectively. While we weren’t sure what we’d think of the function-key system at first (especially after retiring a Microsoft Sidewinder keyboard with a huge and easily accessible volume knob on it), it took less than a day for us to adapt to using the Fn key, located next to the right Ctrl key, to adjust our media playback on the fly. Keyboard backlighting is a largely hit-or-miss undertaking but the CODE keyboard nails it. Not only does it have pleasant and easily adjustable through-the-keys lighting but the key switches the keys themselves are attached to are mounted to a steel plate with white paint. Enough of the light reflects off the interior cavity of the keys and then diffuses across the white plate to provide nice even illumination in between the keys. Highlighting the steel plate beneath the keys brings us to the actual construction of the keyboard. It’s rock solid. The 87-key model, the one we tested, is 2.0 pounds. The 104-key is nearly a half pound heavier at 2.42 pounds. Between the steel plate, the extra-thick PCB board beneath the steel plate, and the thick ABS plastic housing, the keyboard has very solid feel to it. Combine that heft with the previously mentioned thick rubber feet and you have a tank-like keyboard that won’t budge a millimeter during normal use. Examining The Keys This is the section of the review the hardcore typists and keyboard ninjas have been waiting for. We’ve looked at the layout of the keyboard, we’ve looked at the general construction of it, but what about the actual keys? There are a wide variety of keyboard construction techniques but the vast majority of modern keyboards use a rubber-dome construction. The key is floated in a plastic frame over a rubber membrane that has a little rubber dome for each key. The press of the physical key compresses the rubber dome downwards and a little bit of conductive material on the inside of the dome’s apex connects with the circuit board. Despite the near ubiquity of the design, many people dislike it. The principal complaint is that dome keyboards require a complete compression to register a keystroke; keyboard designers and enthusiasts refer to this as “bottoming out”. In other words, the register the “b” key, you need to completely press that key down. As such it slows you down and requires additional pressure and movement that, over the course of tens of thousands of keystrokes, adds up to a whole lot of wasted time and fatigue. The CODE keyboard features key switches manufactured by Cherry, a company that has manufactured key switches since the 1960s. Specifically the CODE features Cherry MX Clear switches. These switches feature the same classic design of the other Cherry switches (such as the MX Blue and Brown switch lineups) but they are significantly quieter (yes this is a mechanical keyboard, but no, your neighbors won’t think you’re firing off a machine gun) as they lack the audible click found in most Cherry switches. This isn’t to say that they keyboard doesn’t have a nice audible key press sound when the key is fully depressed, but that the key mechanism isn’t doesn’t create a loud click sound when triggered. One of the great features of the Cherry MX clear is a tactile “bump” that indicates the key has been compressed enough to register the stroke. For touch typists the very subtle tactile feedback is a great indicator that you can move on to the next stroke and provides a welcome speed boost. Even if you’re not trying to break any word-per-minute records, that little bump when pressing the key is satisfying. The Cherry key switches, in addition to providing a much more pleasant typing experience, are also significantly more durable than dome-style key switch. Rubber dome switch membrane keyboards are typically rated for 5-10 million contacts whereas the Cherry mechanical switches are rated for 50 million contacts. You’d have to write the next War and Peace  and follow that up with A Tale of Two Cities: Zombie Edition, and then turn around and transcribe them both into a dozen different languages to even begin putting a tiny dent in the lifecycle of this keyboard. So what do the switches look like under the classicly styled keys? You can take a look yourself with the included key puller. Slide the loop between the keys and then gently beneath the key you wish to remove: Wiggle the key puller gently back and forth while exerting a gentle upward pressure to pop the key off; You can repeat the process for every key, if you ever find yourself needing to extract piles of cat hair, Cheeto dust, or other foreign objects from your keyboard. There it is, the naked switch, the source of that wonderful crisp action with the tactile bump on each keystroke. The last feature worthy of a mention is the N-key rollover functionality of the keyboard. This is a feature you simply won’t find on non-mechanical keyboards and even gaming keyboards typically only have any sort of key roller on the high-frequency keys like WASD. So what is N-key rollover and why do you care? On a typical mass-produced rubber-dome keyboard you cannot simultaneously press more than two keys as the third one doesn’t register. PS/2 keyboards allow for unlimited rollover (in other words you can’t out type the keyboard as all of your keystrokes, no matter how fast, will register); if you use the CODE keyboard with the PS/2 adapter you gain this ability. If you don’t use the PS/2 adapter and use the native USB, you still get 6-key rollover (and the CTRL, ALT, and SHIFT don’t count towards the 6) so realistically you still won’t be able to out type the computer as even the more finger twisting keyboard combos and high speed typing will still fall well within the 6-key rollover. The rollover absolutely doesn’t matter if you’re a slow hunt-and-peck typist, but if you’ve read this far into a keyboard review there’s a good chance that you’re a serious typist and that kind of quality construction and high-number key rollover is a fantastic feature.  The Good, The Bad, and the Verdict We’ve put the CODE keyboard through the paces, we’ve played games with it, typed articles with it, left lengthy comments on Reddit, and otherwise used and abused it like we would any other keyboard. The Good: The construction is rock solid. In an emergency, we’re confident we could use the keyboard as a blunt weapon (and then resume using it later in the day with no ill effect on the keyboard). The Cherry switches are an absolute pleasure to type on; the Clear variety found in the CODE keyboard offer a really nice middle-ground between the gun-shot clack of a louder mechanical switch and the quietness of a lesser-quality dome keyboard without sacrificing quality. Touch typists will love the subtle tactile bump feedback. Dip switch system makes it very easy for users on different systems and with different keyboard layout needs to switch between operating system and keyboard layouts. If you’re investing a chunk of change in a keyboard it’s nice to know you can take it with you to a different operating system or “upgrade” it to a new layout if you decide to take up Dvorak-style typing. The backlighting is perfect. You can adjust it from a barely-visible glow to a blazing light-up-the-room brightness. Whatever your intesity preference, the white-coated steel backplate does a great job diffusing the light between the keys. You can easily remove the keys for cleaning (or to rearrange the letters to support a new keyboard layout). The weight of the unit combined with the extra thick rubber feet keep it planted exactly where you place it on the desk. The Bad: While you’re getting your money’s worth, the $150 price tag is a shock when compared to the $20-60 price tags you find on lower-end keyboards. People used to large dedicated media keys independent of the traditional key layout (such as the large buttons and volume controls found on many modern keyboards) might be off put by the Fn-key style media controls on the CODE. The Verdict: The keyboard is clearly and heavily influenced by the needs of serious typists. Whether you’re a programmer, transcriptionist, or just somebody that wants to leave the lengthiest article comments the Internet has ever seen, the CODE keyboard offers a rock solid typing experience. Yes, $150 isn’t pocket change, but the quality of the CODE keyboard is so high and the typing experience is so enjoyable, you’re easily getting ten times the value you’d get out of purchasing a lesser keyboard. Even compared to other mechanical keyboards on the market, like the Das Keyboard, you’re still getting more for your money as other mechanical keyboards don’t come with the lovely-to-type-on Cherry MX Clear switches, back lighting, and hardware-based operating system keyboard layout switching. If it’s in your budget to upgrade your keyboard (especially if you’ve been slogging along with a low-end rubber-dome keyboard) there’s no good reason to not pickup a CODE keyboard. Key animation courtesy of Geekhack.org user Lethal Squirrel.       

    Read the article

  • Your thoughts on Best Practices for Scientific Computing?

    - by John Smith
    A recent paper by Wilson et al (2014) pointed out 24 Best Practices for scientific programming. It's worth to have a look. I would like to hear opinions about these points from experienced programmers in scientific data analysis. Do you think these advices are helpful and practical? Or are they good only in an ideal world? Wilson G, Aruliah DA, Brown CT, Chue Hong NP, Davis M, Guy RT, Haddock SHD, Huff KD, Mitchell IM, Plumbley MD, Waugh B, White EP, Wilson P (2014) Best Practices for Scientific Computing. PLoS Biol 12:e1001745. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001745 Box 1. Summary of Best Practices Write programs for people, not computers. (a) A program should not require its readers to hold more than a handful of facts in memory at once. (b) Make names consistent, distinctive, and meaningful. (c) Make code style and formatting consistent. Let the computer do the work. (a) Make the computer repeat tasks. (b) Save recent commands in a file for re-use. (c) Use a build tool to automate workflows. Make incremental changes. (a) Work in small steps with frequent feedback and course correction. (b) Use a version control system. (c) Put everything that has been created manually in version control. Don’t repeat yourself (or others). (a) Every piece of data must have a single authoritative representation in the system. (b) Modularize code rather than copying and pasting. (c) Re-use code instead of rewriting it. Plan for mistakes. (a) Add assertions to programs to check their operation. (b) Use an off-the-shelf unit testing library. (c) Turn bugs into test cases. (d) Use a symbolic debugger. Optimize software only after it works correctly. (a) Use a profiler to identify bottlenecks. (b) Write code in the highest-level language possible. Document design and purpose, not mechanics. (a) Document interfaces and reasons, not implementations. (b) Refactor code in preference to explaining how it works. (c) Embed the documentation for a piece of software in that software. Collaborate. (a) Use pre-merge code reviews. (b) Use pair programming when bringing someone new up to speed and when tackling particularly tricky problems. (c) Use an issue tracking tool. I'm relatively new to serious programming for scientific data analysis. When I tried to write code for pilot analyses of some of my data last year, I encountered tremendous amount of bugs both in my code and data. Bugs and errors had been around me all the time, but this time it was somewhat overwhelming. I managed to crunch the numbers at last, but I thought I couldn't put up with this mess any longer. Some actions must be taken. Without a sophisticated guide like the article above, I started to adopt "defensive style" of programming since then. A book titled "The Art of Readable Code" helped me a lot. I deployed meticulous input validations or assertions for every function, renamed a lot of variables and functions for better readability, and extracted many subroutines as reusable functions. Recently, I introduced Git and SourceTree for version control. At the moment, because my co-workers are much more reluctant about these issues, the collaboration practices (8a,b,c) have not been introduced. Actually, as the authors admitted, because all of these practices take some amount of time and effort to introduce, it may be generally hard to persuade your reluctant collaborators to comply them. I think I'm asking your opinions because I still suffer from many bugs despite all my effort on many of these practices. Bug fix may be, or should be, faster than before, but I couldn't really measure the improvement. Moreover, much of my time has been invested on defence, meaning that I haven't actually done much data analysis (offence) these days. Where is the point I should stop at in terms of productivity? I've already deployed: 1a,b,c, 2a, 3a,b,c, 4b,c, 5a,d, 6a,b, 7a,7b I'm about to have a go at: 5b,c Not yet: 2b,c, 4a, 7c, 8a,b,c (I could not really see the advantage of using GNU make (2c) for my purpose. Could anyone tell me how it helps my work with MATLAB?)

    Read the article

  • Example: Controlling randomizer using code contracts

    - by DigiMortal
    One cool addition to Visual Studio 2010 is support for code contracts. Code contracts make sure that all conditions under what method is supposed to run correctly are met. Those who are familiar with unit tests will find code contracts easy to use. In this posting I will show you simple example about static contract checking (example solution is included). To try out code contracts you need at least Visual Studio 2010 Standard Edition. Also you need code contracts package. You can download package from DevLabs Code Contracts page. NB! Speakers, you can use the example solution in your presentations as long as you mention me and this blog in your sessions. Solution has readme.txt file that gives you steps to go through when presenting solution in sessions. This blog posting is companion posting for Visual Studio solution referred below. As an example let’s look at the following class. public class Randomizer {     public static int GetRandomFromRange(int min, int max)     {         var rnd = new Random();         return rnd.Next(min, max);     }       public static int GetRandomFromRangeContracted(int min, int max)     {         Contract.Requires(min < max, "Min must be less than max");           var rnd = new Random();         return rnd.Next(min, max);     } } GetRandomFromRange() method returns results without any checking. GetRandomFromRangeContracted() uses one code contract that makes sure that minimum value is less than maximum value. Now let’s run the following code. class Program {     static void Main(string[] args)     {         var random1 = Randomizer.GetRandomFromRange(0, 9);         Console.WriteLine("Random 1: " + random1);           var random2 = Randomizer.GetRandomFromRange(1, 1);         Console.WriteLine("Random 2: " + random2);           var random3 = Randomizer.GetRandomFromRangeContracted(5, 5);         Console.WriteLine("Random 3: " + random3);           Console.WriteLine(" ");         Console.WriteLine("Press any key to exit ...");         Console.ReadKey();     } } As we have not turned on support for code contracts the code runs without any problems and we get no warnings by Visual Studio that something is wrong. Now let’s turn on static checking for code contracts. As you can see then code still compiles without any errors but Visual Studio warns you about possible problems with contracts. Click on image to see it at original size.  When we open Error list and run our application we get the following output to errors list. Note that these messages are not shown immediately. There is little delay between application starting and appearance of these messages. So wait couple of seconds before going out of your mind. Click on image to see it at original size.  If you look at these warnings you can see that warnings show you illegal calls and also contracts against what they are going. Third warning points to GetRandomFromRange() method and shows that there should be also problem that can be detected by contract. Download Code Contracts example VS2010 solution | 30KB

    Read the article

  • How does a web server/the http protocol handle version control and compression?

    - by Sune Rasmussen
    When a client browser requests a file from the web server, I know that some kind of check is performed, because the files needed to serve the web page may already be cached by the web browser. So, if a file exists in the cache, no files are sent. But if the file on the server has changed since the file was cached in the browser, the file is sent and updated anyhow. Then, if you have compression like gzipping enabled on the server, the files that are to be provided to the client must be gzipped on the way, requiring some amount of server side processing. But how is this managed? The logical approach seems to me, that the web server should have a cache as well, containing the newest version of all files that have been requested within a certain time span, thus a compressed version of these files, so that compression would not have to be done each time a files is requested. And also, how are files eventually requested? Does the browser ask for files, each time it encounters one in the HTML code and the specific file is not stored in the local cache, or does it sum all the files that are needed up and ask for the whole bunch at the same time? But that's only guessing from a programming point of view, and I don't really know. If the answers are very different among web server systems, I'm primarily interested in Apache, but other answers are appreciated, too.

    Read the article

  • Error trapping for a missing data source in a Spring MVC / Spring JDBC web app [migrated]

    - by Geeb
    I have written a web app that uses Spring MVC libraries and Spring JDBC to connect to an Oracle DB. (I don't use any ORM type libraries as I create stored procedures on Oracle that do my stuff and I'm quite happy with that.) I use a connection pool to Oracle managed by the Tomcat container The app generally works absolutely fine by the way! BUT... I noticed the other day when I tried to set up the app on another Tomcat instance that I had forgotten to configure the connection pool and obviously the app could not get hold of an org.apache.commons.dbcp.BasicDataSource object, so it crashed. I define the pool params in the tomcat "context.conf" In my "web.xml" I have: <servlet> <servlet-name>appServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/Spring/appServlet/servlet-context.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>appServlet</servlet-name> <!-- Map *everything* to appServlet --> <url-pattern>/</url-pattern> </servlet-mapping> <resource-ref> <description>Oracle Datasource example</description> <res-ref-name>jdbc/ora1</res-ref-name> <res-type>org.apache.commons.dbcp.BasicDataSource</res-type> <res-auth>Container</res-auth> </resource-ref> And I have a Spring "servlet-context.xml" where JNDI is used to map the data source object provided by the connection pool to a Spring bean with the ID of "dataSource": <jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/ora1" resource-ref="true" /> Here's the question: Where do I trap the case where the database cannot be accessed for whatever reason? I don't want the user to see a yard-and-a-half of Java stack trace in their browser, rather a nicer message that tells them there is a database problem etc. It seems that my app tries to configure the "dataSource" bean (in "servlet-context.xml") before any code has tested it can actually provide a dataSource object from the pool?! Maybe I'm not fully understanding exactly what is going on in these stages of the app firing up ... Thanks for any advice!

    Read the article

< Previous Page | 112 113 114 115 116 117 118 119 120 121 122 123  | Next Page >