Search Results

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

Page 336/563 | < Previous Page | 332 333 334 335 336 337 338 339 340 341 342 343  | Next Page >

• Create a fast algorithm for a "weighted" median

  - by Hameer Abbasi

  Suppose we have a set S with k elements of 2-dimensional vectors, (x, n). What would be the most efficient algorithm to calculate the median of the weighted set? By "weighted set", I mean that the number x has a weight n. Here is an example (inefficient due to sorting) algorithm, where Sx is the x-part, and Sn is the n-part. Assume that all co-ordinate pairs are already arranged in Sx, with the respective changes also being done in Sn, and the sum of n is sumN: sum <= 0; i<= 0 while(sum < sumN) sum <= sum + Sn(i) ++i if(sum > sumN/2) return Sx(i) else return (Sx(i)*Sn(i) + Sx(i+1)*Sn(i+1))/(Sn(i) + Sn(i+1)) EDIT: Would this hold in two or more dimensions, if we were to calculate the median first in one dimension, then in another, with n being the sum along that dimension in the second pass?

  Read the article

• Handle HTTPS Request in Proxy Server by C#

  - by Masoud Zohrabi

  I'm trying to write a Home Proxy Server in C# and I almost succeeded but I have problem to handle HTTPS requests (CONNECT). I don't know really how to handle this type of requests. In my studies I realized that for this requests we must to connect client to target host directly. Steps for these requests (that I realized): Receive first request from client (CONNECT https://www.example.ltd:443 HTTP/1.1) and send that to target host Send HTTP/1.1 200 Connection Established\r\n\r\n to client Listen to both sockets (client and target host) and send receives from each other to each other Listen until one of sockets disconnected Is this correct? If it is, how?

  Read the article

• How to store prices that have effective dates?

  - by lal00

  I have a list of products. Each of them is offered by N providers. Each providers quotes us a price for a specific date. That price is effective until that provider decides to set a new price. In that case, the provider will give the new price with a new date. The MySQL table header currently looks like: provider_id, product_id, price, date_price_effective Every other day, we compile a list of products/prices that are effective for the current day. For each product, the list contains a sorted list of the providers that have that particular product. In that way, we can order certain products from whoever happens to offer the best price. To get the effective prices, I have a SQL statement that returns all rows that have date_price_effective >= NOW(). That result set is processed with a ruby script that does the sorting and filtering necessary to obtain a file that looks like this: product_id_1,provider_1,provider_3,provider8,provider_10... product_id_2,provider_3,provider_2,provider1,provider_10... This works fine for our purposes, but I still have an itch that a SQL table is probably not the best way to store this kind of information. I have that feeling that this kind of problema has been solved previously in other more creative ways. Is there a better way to store this information other than in SQL? or, if using SQL, is there a better approach than the one I'm using?

  Read the article

• Object oriented wrapper around a dll

  - by Tom Davies

  So, I'm writing a C# managed wrapper around a native dll. The dll contains several hundred functions. In most cases, the first argument to each function is an opaque handle to a type internal to the dll. So, an obvious starting point for defining some classes in the wrapper would be to define classes corresponding to each of these opaque types, with each instance holding and managing the opaque handle (passed to its constructor) Things are a little awkward when dealing with callbacks from the dll. Naturally, the callback handlers in my wrapper have to be static, but the callbacks arguments invariable contain an opaque handle. In order to get from the static callback back to an object instance, I've created a static dictionary in each class, associating handles with class instances. In the constructor of each class, an entry is put into the dictionary, and this entry is then removed in the Destructors. When I receive a callback, I can then consult the dictionary to retrieve the class instance corresponding to the opaque reference. Are there any obvious flaws to this? Something that seems to be a problem is that the existence static dictionary means that the garbage collector will not act on my class instances that are otherwise unreachable. As they are never garbage collected, they never get removed from the dictionary, so the dictionary grows. It seems I might have to manually dispose of my objects, which is something absolutely would like to avoid. Can anyone suggest a good design that allows me to avoid having to do this?

  Read the article

• Queuing rpc calls

  - by alfa64

  i'm designing a system wich listen to json rpc calls from clients, piles it up inside a list, and if it gets full it should store them in a DB and keep recieving calls. My original plan is to listen to the rpc calls from Perl with the json-rpc and put them in the array. The clients do some long polling in another server to get responses as they appear. What is this blocking/noblocking thing? Should i do a script for node.js to listen to the calls? What do you think is a good practice in this case? The objective is to listen as much calls as possible.

  Read the article

• Architecture for a site "blog"/"news reel"

  - by DavidScherer

  I really don't want to undertake handling blog/news posts within a site I'm working on and would much rather use some other software that's fairly bare-bones that will manage the posts and then I can just pull posts from the DB or an API. Does anyone have any experience with a nice, lightweight OS Blog type software that has either an API or is basic enough to simply pull Data from the database? I really only need the software for managing, I plan to display all the posts programatically through MVC.

  Read the article

• What is the best toolkit for writing long technical texts?

  - by thr

  I'm looking for a toolkit in the form of one or a couple of applications that can be used to write long technical texts (such as an introduction to a programming language). What applications (or combination of) are suitable for this? How should said applications be setup (for example how would one setup MS Word to best fit writing a technical text)? How do you deal with source code, syntax coloring and formatting? In the case of it being several applications, how do you interact between them?

  Read the article

• Fetching database query through function

  - by Shubham Maurya

  I am sick of connecting database in each script i need a more OOP approach to fetching database results. ex like wordpress use wpdb class to fetch results. This what wordpress does to get data <?php $posts = $wpdb->get_results("SELECT ID, post_title FROM $wpdb->posts WHERE post_status = 'publish' AND post_type='post' ORDER BY comment_count DESC LIMIT 0,4") ?> How can i create the same feature too using any class or function and use it in my script Thank you

  Read the article

• How is this recursion properly working when it is iterated through [on hold]

  - by Rakso Zrobin

  Here is my code right now: hasht= {"A":["B", "D", "E"], "B":["C"], "C":["D", "E"], "D":["C", "E"], "E":["B"]} paths=[] def recusive(start, finish, started=true): if start==finish and !started: return start else: for i in hasht[start]: path= start+ recusive(i,finish,false) paths.append(path) print (recusive("C","C",1)) print paths # [CDC, CDEBC, CEBC] I am trying to generate a table like the one on the bottom, but am running into the problem of the string and the array not being able to concatenate. When I just return however, it returns CDC and works, however, exiting the function as return is meant to do. I am wondering how I can improve my code here to (1) make it work, (2) why my logic was faulty. For example, I understand that it generates say [DC], but I am confused as to how to go around that. perhaps index the value returned?

  Read the article

• OAuth2 vs Public API

  - by Adam Tannon

  My understanding of OAuth (2.0) is that its a software stack and protocol to allow 2+ web apps to share information about a single end user. User A is a member of Site B and Site C; Site B wants to fetch some data from Site C about User A, and this is where OAuth steps in. So first off, if this assessment is incorrect, please begin by clarifying this for me and correcting me! Assuming I'm on the right track, then I guess I'm not seeing the need for OAuth to begin with (!). I'm sure I'm just not seeing the "forest through the trees" here, but the way I see it, couldn't Site C just expose a public API that Site B could use to fetch the same data (sans OAuth)? If Site C required user credentials to access the data, could this public API just use HTTPS for secure transport and require username/password as a part of each API call? Again, I'm sure I'm missing something, but I'm just not understanding why I would need OAuth when a secure, public API written and exposed by Site C seems more than capable of delivering what Site B needs regarding User A. In general, I'm looking for a set of guidelines to go by when deciding to choose between using OAuth for my web apps or just writing my own web service ( exposing public API). Thanks in advance!

  Read the article

• in memory datastore in haskell

  - by Simon

  I want to implement an in memory datastore for a web service in Haskell. I want to run transactions in the stm monad. When I google hash table steam Haskell I only get this: Data. BTree. HashTable. STM. The module name and complexities suggest that this is implemented as a tree. I would think that an array would be more efficient for mutable hash tables. Is there a reason to avoid using an array for an STM hashtable? Do I gain anything with this stem hash table or should I just use a steam ref to an IntMap?

  Read the article

• How to process large files in NetLogo? [closed]

  - by user65597

  I am running into problems in NetLogo with large *.csv / *.txt files. The documents can consist of about 1 million data sets and I need to read them (to eventually create a diagram based on the data). With the most straightforward source code, my program needs about 2 minutes to process these files. How should I approach reading such large data files faster in NetLogo? Is NetLogo even suitable for such tasks (as it seems to be designed more for teaching and learning)?

  Read the article

• a program called football team

  - by bosco

  how do you solve the following using java?Soccer team A is made up of the bench and people on the lineup. The program should enable the user to select a lineup and assign positions to players. It should also allow for the manipulation of attributes such as age, jersey number, fitness status, yellow and red cards, state whether one is a goalkeeper, defender, etc. Information such as losses ,wins and points of the entire team are also important. the above task requires the to use of: Static members for attributes with values common to all objects of the same class The “this” keyword to distinguish constructor parameters and data members Constructor overloading Method overloading Use two collections of the type Arraylist to store objects.

  Read the article

• What is wiser for me? Eclipse or IntelliJ aka not another IDE war. [closed]

  - by Xorty

  I hope you guys won't take this as attempt of flamewar :) I am quite happy Eclipse user atm, but I am having little dilema: All big companies in my area are using Eclipse, and I quite like Eclipse, but IntelliJ is simply smarter and comfortable in some things. What would you do? If I decide to switch to IDEA I am afraid that I'll regret it someday ... And I don't want to remember like all shortcuts in both eclipse & IDEA, that's simply too much :)

  Read the article

• Mercurial release management. Rejecting changes that fail testing

  - by MYou

  Researching distributed source control management (specifically mercurial). My question is more or less what is the best practice for rejecting entire sets of code that fail testing? Example: A team is working on a hello world program. They have testers and a scheduled release coming up with specific features planned. Upcoming Release: Add feature A Add feature B Add feature C So, the developers make their clones for their features, do the work and merge them into a QA repo for the testers to scrutinize. Let's say the testers report back that "Feature B is incomplete and in fact dangerous", and they would like to retest A and C. End example. What's the best way to do all this so that feature B can easily be removed and you end up with a new repo that contains only feature A and C merged together? Recreate the test repo? Back out B? Other magic?

  Read the article

• API always returns JSONObject or JSONArray Best practices

  - by Michael Laffargue

  I'm making an API that will return data in JSON. I also wanted on client side to make an utility class to call this API. Something like : JSONObject sendGetRequest(Url url); JSONObject sendPostRequest(Url url, HashMap postData); However sometimes the API send back array of object [{id:1},{id:2}] I now got two choices (): Make the method test for JSONArray or JSONObject and send back an Object that I will have to cast in the caller Make a method that returns JSONObject and one for JSONArray (like sendGetRequestAndReturnAsJSONArray) Make the server always send Arrays even for one element Make the server always send Objects wrapping my Array I going for the two last methods since I think it would be a good thing to force the API to send consistent type of data. But what would be the best practice (if one exist). Always send arrays? or always send objects?

  Read the article

• Designs for outputting to a spreadsheet

  - by Austin Moore

  I'm working on a project where we are tasked to gather and output various data to a spreadsheet. We are having tons of problems with the file that holds the code to write the spreadsheet. The cell that the data belongs to is hardcoded, so anytime you need to add anything to the middle of the spreadsheet, you have to increment the location for all the fields after that in the code. There are random blank rows, to add padding between sections, and subsections within the sections, so there's no real pattern that we can replicate. Essentially, anytime we have to add or change anything to the spreadsheet it requires a many long and tedious hours. The code is all in this one large file, hacked together overtime in Perl. I've come up with a few OO solutions, but I'm not too familiar with OO programming in Perl and all my attempts at it haven't been great, so I've shied away from it so far. I've suggested we handle this section of the program with a more OO friendly language, but we can't apparently. I've also suggested that we scrap the entire spreadsheet idea, and just move to a webpage, but we can't do that either. We've been working on this project for a few months, and every time we have to change that file, we all dread it. I'm thinking it's time to start some refactoring. However, I don't even know what could make this file easier to work with. The way the output is formatted makes it so that it has to be somewhat hardcoded. I'm wondering if anyone has insight on any design patterns or techniques they have used to tackle a similar problem. I'm open to any ideas. Perl specific answers are welcome, but I am also interested in language-agnostic solutions.

  Read the article

• Inexpensive generation of hierarchical unique IDs

  - by romaninsh

  My application is building a hierarchical structure like this: root = { 'id': 'root', 'children': [ { 'name': 'root_foo', 'children': [] }, { 'id': 'root_foo2', 'children': [ { 'id': 'root_foo2_bar', 'children': [] } ] } ] } in other words, it's a tree of nodes, where each node might have child elements and unique identifier I call "id". When a new child is added, I need to generate a unique identifier for it, however I have two problems: identifiers are getting too long adding many children takes slower, as I need to find first available id My requirement is: naming of a child X must be determined only from the state in their ancestors When I re-generate tree with same contents, the IDs must be same or in other words, when we have nodes A and B, creating child in A, must not affect the name given to children of B. I know that one way to optimize would be to introduce counter in each node and append it to the names which will solve my performance issue, but will not address the issue with the "long identifiers". Could you suggest me the algorithm for quickly coming up with new IDs?

  Read the article

• Proxied calls not working as expected

  - by AndyH

  I have been modifying an application to have a cleaner client/server split to allow for load splitting and resource sharing etc. Everything is written to an interface so it was easy to add a remoting layer to the interface using a proxy. Everything worked fine. The next phase was to add a caching layer to the interface and again this worked fine and speed was improved but not as much as I would have expected. On inspection it became very clear what was going on. I feel sure that this behavior has been seen many times before and there is probably a design pattern to solve the problem but it eludes me and I'm not even sure how to describe it. It is easiest explained with an example. Let's imagine the interface is interface IMyCode { List<IThing> getLots( List<String> ); IThing getOne( String id ); } The getLots() method calls getOne() and fills up the list before returning. The interface is implemented at the client which is proxied to a remoting client which then calls the remoting server which in turn calls the implementation at the server. At the client and the server layers there is also a cache. So we have :- Client interface | Client cache | Remote client | Remote server | Server cache | Server interface If we call getOne("A") at the client interface, the call is passed to the client cache which faults. This then calls the remote client which passes the call to the remote server. This then calls the server cache which also faults and so the call is eventually passed to the server interface which actually gets the IThing. In turn the server cache is filled and finally the client cache also. If getOne("A") is again called at the client interface the client cache has the data and it gets returned immediately. If a second client called getOne("B") it would fill the server cache with "B" as well as it's own client cache. Then, when the first client calls getOne("B") the client cache faults but the server cache has the data. This is all as one would expect and works well. Now lets call getLots( [ "C", "D" ] ). This works as you would expect by calling getOne() twice but there is a subtlety here. The call to getLots() cannot directly make use of the cache. Therefore the sequence is to call the client interface which in turn calls the remote client, then the remote server and eventually the server interface. This then calls getOne() to fill the list before returning. The problem is that the getOne() calls are being satisfied at the server when ideally they should be satisfied at the client. If you imagine that the client/server link is really slow then it becomes clear why the client call is more efficient than the server call once the client cache has the data. This example is contrived to illustrate the point. The more general problem is that you cannot just keep adding proxied layers to an interface and expect it to work as you would imagine. As soon as the call goes 'through' the proxy any subsequent calls are on the proxied side rather than 'self' side. Have I failed to learn or not learned something correctly? All this is implemented in Java and I haven't used EJBs. It seems that the example may be confusing. The problem is nothing to do with cache efficiencies. It is more to do with an illusion created by the use of proxies or AOP techniques in general. When you have an object whose class implements an interface there is an assumption that a call on that object might make further calls on that same object. For example, public String getInternalString() { return InetAddress.getLocalHost().toString(); } public String getString() { return getInternalString(); } If you get an object and call getString() the result depends where the code is running. If you add a remoting proxy to the class then the result could be different for calls to getString() and getInternalString() on the same object. This is because the initial call gets 'deproxied' before the actual method is called. I find this not only confusing but I wonder how I can control this behavior especially as the use of the proxy may be by a third party. The concept is fine but the practice is certainly not what I expected. Have I missed the point somewhere?

  Read the article

• Why would you hire in-house software developers instead of outsourcing them to develop a product for your company?

  - by Terence Ponce

  Why would you hire in-house over outsourcing in developing a product for your company? I can only think of a few but I'm not entirely sure if they're good enough reason. This is actually for a debate that I'm going to have in class. I'm more inclined on the outsourcing part but unfortunately, I was asked to switch to the in-house side of the debate. Any ideas? UPDATE Thanks for the answers guys. The debate went well because of them. I'm pretty sure our side won the debate because of the points presented here.

  Read the article

• How to verify the Liskov substitution principle in an inheritance hierarchy?

  - by Songo

  Inspired by this answer: Liskov Substitution Principle requires that Preconditions cannot be strengthened in a subtype. Postconditions cannot be weakened in a subtype. Invariants of the supertype must be preserved in a subtype. History constraint (the "history rule"). Objects are regarded as being modifiable only through their methods (encapsulation). Since subtypes may introduce methods that are not present in the supertype, the introduction of these methods may allow state changes in the subtype that are not permissible in the supertype. The history constraint prohibits this. I was hoping if someone would post a class hierarchy that violates these 4 points and how to solve them accordingly. I'm looking for an elaborate explanation for educational purposes on how to identify each of the 4 points in the hierarchy and the best way to fix it. Note: I was hoping to post a code sample for people to work on, but the question itself is about how to identify the faulty hierarchies :)

  Read the article

• Understanding a codebase [duplicate]

  - by jojo modjo

  This question already has an answer here: How do you dive into large code bases? 31 answers What kind of practices should one employ to increase his understanding of a codebase. I will be a bit more specific and narrow down the question to the domain of an application that includes asynchronous jobs, python, celery, mysql, sqlalchemy and flask. It's a code base that creates reports basically. I would like to have a better understanding of the codebase.

  Read the article

• Just getting started in Spring and my preference is XML config over annotations. Correct or not?

  - by John Munsch

  After having read through some of the Spring docs my inclination is towards using a XML config file rather than annotations on the classes themselves. My reasoning is that by doing so you avoid tying your POJOs to a particular framework. Based on your experience with Spring, are there any advantages that XML configuration have over an annotation based configuration, and if not what are the disadvantages?

  Read the article

• Easy to use JSON Web Service Hosts?

  - by Serguei Fedorov

  I saw this being used by someone in a college class once and cannot find anything that is analogous to it. I am not sure if this is the right place to ask about something like this, but hopefully I can get some direction. I want to write an app which uses web services that can obtain and push data back to the client apps. Right now I am gathering up the design and documentation of this app. Not having to code the web service myself would reduce development time by a lot; instead using an easy to setup web service that will be easy to setup and manage. Either XML based on JSON based is totally fine; though I would prefer JSON for its reduced overhead. Like I said I have seen this demonstrated before; you define the data structure to be stored and how it is treated. I cannot find the person who demonstrated this; hopefully maybe someone can suggest something? The service he used was free with a limited amount of requests allowed. EDIT: He was using an online service to do this not a script which is installed onto an existing web hosting account. Thank you!

  Read the article

• How do I get started with HTML5 when I come from a Flash background?

  - by daniel.sedlacek

  How do I convert Flash web applications to HTML 5? What is the recommended workflow to learn HTML5? What tools should I install? What SDK? Where to start? How to test? How to debug? What do I read? I'm familiar with Eclipse, should I install Aptana? If yes, what's next? I would like to start lightweight but I would also like to learn the good practices from the beginning. UPDATE: I understand that what is often labelled as "HTML5 development" is in fact a mixture of HTML, CSS, JS and more, however I don't believe that bigger projects are developed in Notepad. That is why I am asking you to reveal your tips and tricks about your workflow.

  Read the article

< Previous Page | 332 333 334 335 336 337 338 339 340 341 342 343  | Next Page >