Search Results

Search found 3758 results on 151 pages for 'efficient'.

Page 15/151 | < Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >

  • Alternatives to FastDateFormat for efficient date parsing?

    - by Tom Tucker
    Well aware of performance and thread issues with SimpleDateFormat, I decided to go with FastDateFormat, until I realized that FastDateFormat is for formatting only, no parsing! Is there an alternative to FastDateFormat, that is ready to use out of the box and much faster than SimpleDateFormat? I believe FastDateFormat is one of the faster ones, so anything that is about as fast would do. Just curious , any idea why FastDateFormat does not support parsing? Doesn't it seriously limit its use? Thanks! EDIT Holy crap, I just left a comment and that literally REMOVED a good answer! This appears a serious bug on stackoverflow!

    Read the article

  • Most efficient way to animate a path?

    - by mystify
    I have a fullscreen path which consists of about 20 lines. Currently I am animating changes in this path using an NSTimer which frequently calls -setNeedsDisplay. Believe me: Performance sucks absolutely. I slightly remember that there was some better way to animate paths on the iPhone. Some kind of special CA layer. I don't remember anymore it's exact name. Who knows?

    Read the article

  • Highly efficient filesystem APIs for certain kinds of operations

    - by romkyns
    I occasionally find myself needing certain filesystem APIs which could be implemented very efficiently if supported by the filesystem, but I've never heard of them. For example: Truncate file from the beginning, on an allocation unit boundary Split file into two on an allocation unit boundary Insert or remove a chunk from the middle of the file, again, on an allocation unit boundary The only way that I know of to do things like these is to rewrite the data into a new file. This has the benefit that the allocation unit is no longer relevant, but is extremely slow in comparison to some low-level filesystem magic. I understand that the alignment requirements mean that the methods aren't always applicable, but I think they can still be useful. For example, a file archiver may be able to trim down the archive very efficiently after the user deletes a file from the archive, even if that leaves a small amount of garbage either side for alignment reasons. Is it really the case that such APIs don't exist, or am I simply not aware of them? I am mostly interested in NTFS, but hearing about other filesystems will be interesting too.

    Read the article

  • Efficient questions

    - by rayman
    Hi, I have to manage xml's and Strings in my app. by efficenty and memory saving, is collection(ArrayList) will be much more 'expensive' then array of Strings? another issue is: i could use the content as regular String, or XML.. is working with XML also makes it more 'expensive' ? when i say i expensive i talk about taking system sources. please tell me by any of your exprience if the diffrences are significant? thanks, ray.

    Read the article

  • SQLAlchemy: an efficient/better select by primary keys?

    - by hadrien
    Yet another newbie question.. Let's say I have an user table in declarative mode: class User(Base): __tablename__ = 'user' id = Column(u'id', Integer(), primary_key=True) name = Column(u'name', String(50)) When I have a list of users identifiers, I fetch them from db with: user_ids = [1, 2, 3, 4, 5] users = Session.query(User).filter(User.id.in_(user_ids)).all() I dislike using in_ because I think I learned it has bad performance on indexed fields (is that true/false?). Anyway, is there a better way doing that query? Thanks!

    Read the article

  • What is the most efficient approach to fetch category tree, products, brands, counts by subcategory

    - by alex227
    Symfony 1.4 + Doctrine 1.2. What is the best way to minimize the number of queries to retrieve products, subcategories of current category, product counts by subcategory and brand for the result set of the query below? Categories are a nested set. Here is my query: $q = Doctrine_Query::create() ->select('c.*, p.product,p.price, b.brand') ->from('Category c') ->leftJoin('c.Product p') ->leftJoin('p.Brand b') ->where ('c.root_id = ?', $this->category->getRootId()) ->andWhere('c.lft >= ?', $this->category->getLft()) ->andWhere('c.rgt <= ?', $this->category->getRgt()) ->setHydrationMode(Doctrine_Core::HYDRATE_ARRAY); $treeObject = Doctrine::getTable('Category')->getTree(); $treeObject->setBaseQuery($q); $this->treeObject = $treeObject; $treeObject->resetBaseQuery(); $this->products = $q->execute();

    Read the article

  • more efficient version of this?

    - by john connor
    i have this thingy here : function numOfPackets(bufferSize, packetSize) { if (bufferSize <= 0 || packetSize > bufferSize) return 0; if (packetSize < 0) throw Error(); var out = 0; for(;;){ out++; bufferSize = bufferSize - packetSize; if( packetSize > bufferSize ) break; } return out; } which i run at often , can u give me more efficent variant of it?

    Read the article

  • Most efficient way to make an activity log

    - by Nathan
    I am making a "recent activity" tab to profiles on my site and I also am going to have a log for moderators to see everything that happens on the site. This would require making an activity log of some sort. I just don't know what would be better. I have 2 options: Make a table called "activity" and then every time someone does something, add a record to it with the type of action, user id, timestamp, etc. Problem: table could get very long. Join all 3 tables (questions, answers, answer_comments) and then somehow show all these on the page in the order in which the action was taken. Problem: this would be extremely hard because I have no clue how I could make it say "John commented on an answer on Question Title Here" by just joining 3 tables. Does anyone know of a better way of making an activity log in this situation? I am using PHP and MySQL. If this is either too inefficient or hard I will probably just forget the Recent Activity tab on profiles but I still need an activity log for moderators. Here's some SQL that I started making for option 2, but this would not work because there is no way of detecting whether the action is a comment, question, or answer when I echo the info in a while loop: SELECT q.*, a.*, ac.* FROM questions q JOIN answers a ON a.questionid = q.qid JOIN answer_comments ac ON c.answerid = a.ans_id WHERE q.user = $userid AND a.userid = $userid AND ac.userid = $userid ORDER BY q.created DESC, a.created DESC, ac.created DESC Thanks in advance for any help!

    Read the article

  • Efficient retrieval of lists over WebServices

    - by Chris
    I have a WCF WebService that uses LINQ and EF to connect to an SQL database. I have an ASP.NET MVC front end that collects its data from the webservice. It currently has functions such as List<Customer> GetCustomers(); As the number of customers increases massively the amount of data being passed increases also reducing efficiency. What is the best way to "page data" across WebServices etc. My current idea is to implement a crude paging system such as List<Customer> GetCustomers(int start, int length); This, however, means I would have to replicate such code for all functions returning List types. It is unfortunate that I cannot use LINQ as it would be much nicer. Does anyone have any advice or ideas of patterns to implement that would be "as nice as possible" Thanks

    Read the article

  • What is the Quicker / More Efficient CSS styling

    - by Sessa
    I have been curious as to which method of CSS styling is quicker (rendering wise) and then from simply a best practices perspective which method makes more sense (pretty subjective I would say?). I can create base classes like: .rounded-corners-5 { -moz-border-radius: 5px; -webkit-border-radius: 5px; border-radius: 5px; } OR I can do the other method of applying styles to multiple IDs/Classes: #box1, #header, #container, .titles { -moz-border-radius: 5px; -webkit-border-radius: 5px; border-radius: 5px; }

    Read the article

  • Dimensions of a collection, and how to traverse it in an efficient, elegant manner

    - by Bruce Ferguson
    I'm trying to find an elegant way to deal with multi-dimensional collections in Scala. My understanding is that I can have up to a 5 dimensional collection using tabulate, such as in the case of the following 2-Dimensional array: val test = Array.tabulate[Double](row,col)(_+_) and that I can access the elements of the array using for(i<-0 until row) { for(j<-0 until col) { test(i)(j) = 0.0 } } If I don't know a priori what I'm going to be handling, what might be a succinct way of determining the structure of the collection, and spanning it, without doing something like: case(Array(x)) => for(i<-1 until dim1) { test(i) = 0.0 } case(Array(x,y)) => for(i<-1 until dim1) { for(j<-1 until dim2) { test(i)(j) = 0.0 } } case(Array(x,y,z)) => ... The dimensional values n1, n2, n3, etc... are private, right? Also, would one use the same trick of unwrapping a 2-D array into a 1-D vector when dealing with n-Dimensional objects if I want a single case to handle the traversal? Thanks in advance Bruce

    Read the article

  • Efficient job progress update in web application

    - by Endru6
    Hi, Creating a web application (Django in my case, but I think the question is more general) that is administrating a cluster of workers doing queued jobs, there is a need to track each jobs progress. When I've done it using database UPDATE (PostgreSQL in this case), it severely hits the database performance, because each UPDATE creates a new row in a table, and in my case only vacuuming DB removes obsolete rows. Having 30 jobs running and reporting progress every 1 minute DB may require vacuuming (and it means huge slow downs on a front end side for all the employees working with the system) every 10 days. Because the progress information isn't critical, ie. it doesn't have to be persistent, how would you do the progress updates from jobs without using an overhead database implies? There are 30 worker servers, each doing 1 or 2 jobs simultaneously, 1 front end server which serves a web application to users, and 1 database server.

    Read the article

  • Efficient quaternion angular velocity

    - by user3736210
    I have an orientation expressed with a quaternion and an angular velocity expressed as either a quaternion or a number (radians per second around the original orientation). I understand how to do this using conversion to axis-angle but that method is rather computationally expensive and is not a realistic option. How would I go about modifying the orientation quaternion given a time interval (in seconds)? I need a solution for both cases (the quaternion and the number).

    Read the article

  • Efficient mapping for a particular finite integer set

    - by R..
    I'm looking for a small, fast (in both directions) bijective mapping between the following list of integers and a subset of the range 0-127: 0x200C, 0x200D, 0x200E, 0x200F, 0x2013, 0x2014, 0x2015, 0x2017, 0x2018, 0x2019, 0x201A, 0x201C, 0x201D, 0x201E, 0x2020, 0x2021, 0x2022, 0x2026, 0x2030, 0x2039, 0x203A, 0x20AA, 0x20AB, 0x20AC, 0x20AF, 0x2116, 0x2122 One obvious solution is: y = x>>2 & 0x40 | x & 0x3f; x = 0x2000 | y<<2 & 0x100 | y & 0x3f; Edit: I was missing some of the values, particularly 0x20Ax, which don't work with the above. Another obvious solution is a lookup table, but without making it unnecessarily large, a lookup table would require some bit rearrangement anyway and I suspect the whole task can be better accomplished with simple bit rearrangement. For the curious, those magic numbers are the only "large" Unicode codepoints that appear in legacy ISO-8859 and Windows codepages.

    Read the article

  • More efficient way of writing this javascript

    - by nblackburn
    I am creating a contact form for my website and and using javascript to the first layer of validation before submitting it which is then checked again via php but i am relatively new to javascript, here is my script... $("#send").click(function() { var fullname = $("input#fullname").val(); var email = $("input#email").val(); var subject = $("input#subject").val(); var message = $("textarea#message").val(); if (fullname == ""){ $("input#fullname").css("background","#d02624"); $("input#fullname").css("color","#121212"); }else{ $("input#fullname").css("background","#121212"); $("input#fullname").css("color","#5c5c5c"); } if (email == ""){ $("input#email").css("background","#d02624"); $("input#email").css("color","#121212"); }else{ $("input#email").css("background","#121212"); $("input#email").css("color","#5c5c5c"); } if (subject == ""){ $("input#subject").css("background","#d02624"); $("input#subject").css("color","#121212"); }else{ $("input#subject").css("background","#121212"); $("input#subject").css("color","#5c5c5c"); } if (message == ""){ $("textarea#message").css("background","#d02624"); $("textarea#message").css("color","#121212"); }else{ $("textarea#message").css("background","#121212"); $("textarea#message").css("color","#5c5c5c"); } if (name && email && subject && message != ""){ alert("YAY"); } }); How can i write this more efficiently and make the alert show if all the fields are filled out, thanks.

    Read the article

  • Need an efficient algorithm solve this kind of complex structure

    - by Rizvan
    Problem Statement is : Given 2 Dimensional array, print output for example If 4 rows and 6 columns, output would be: 1 2 3 4 5 6 16 17 18 19 20 7 15 24 23 22 21 8 14 13 12 11 10 9 I tried it is looking like square within square but when I attempted this problem, I put so many while and if loops but didn't got exact answer. If row and columns increases how to handle it? This is not homework. I was learning solving complex structure so I need to understand it by some guidance.

    Read the article

  • SDK2 query for counting: which is more efficient?

    - by user1195996
    I have an app that is displaying metrics about defects in a project. I have the option of making one query that returns all the defects, and from that I can break out about four different metrics (How many defects escaped QA in 90 days, 180 days, and then the same metrics again but only counting sev1/sev2 defects). I could make four queries and limit the results to one so that I just get a count for each. Or I could make one query that encompass them all (all defects that escaped QA in 180 days) and then count up the difference. I'm figuring worst case, the number of defects that escaped QA in the last six months will generally be less than 100, certainly less 500 worst case. Which would you do-- four queryies with one result each, or one single query that on average might return 50, perhaps worst case 500? And I guess the key question is-- where are the inflections points? Perhaps I have more metrics tomorrow (who knows, 8?) and a different average defect counts. Is there a rule of thumb I could use to help choose which approach?

    Read the article

  • Make SQL query more efficient

    - by Webnet
    I currently have this query which runs 2 of the exact same sub queries but pull different data. When I make the values comma separated it throws an SQL error saying the sub query can return only one value. Is there anything else I can do to avoid running multiple sub queries? SELECT product_id, ( SELECT COUNT(listing_id) FROM ebay_archive_product_listing_assoc WHERE product_id = product_master.product_id) as listing_count, sku, type_id, ( SELECT AVG(ebay_archive_listing.current_price), AVG(ebay_archive_listing.buy_it_now_price) FROM ebay_archive_listing WHERE id IN ( SELECT listing_id FROM ebay_archive_product_listing_assoc WHERE product_id = product_master.product_id ) AND ebay_archive_listing.start_time >= '.$startTimestamp.' AND ebay_archive_listing.start_time <= '.$endTimestamp.' AND ebay_archive_listing.current_price > 0 ) as average_bid_price, ( SELECT FROM ebay_archive_listing WHERE id IN ( SELECT listing_id FROM ebay_archive_product_listing_assoc WHERE product_id = product_master.product_id ) AND ebay_archive_listing.start_time >= '.$startTimestamp.' AND ebay_archive_listing.start_time <= '.$endTimestamp.' AND ebay_archive_listing.buy_it_now_price > 0 ) as average_buyout_price FROM product_master I'm aware of the syntax error... I'm selecting 2 seperate averages and am wondering if I can do it any simpler way.

    Read the article

  • make it simpler and efficient

    - by gcc
    temp1=*tutar[1]; //i hold input in char *tutar[] if(temp1!='x'||temp1!='n') arrays[1]=malloc(sizeof(int)*num_arrays); //if second input is int a=0; n=i; for(i=1;i<n;++i) { temp1=*tutar[i]; if(temp1=='d') { ++i; j=atoi(tutar[i]); free(arrays[j]); continue; } if(temp1=='x') break; if(temp1=='n')//if it is n { a=0; ++j; arrays[j]=malloc(sizeof(int)*num_arrays);//create and allocate continue; } ++a; if(a>num_arrays) //resize the array arrays[j]=realloc(arrays[j],sizeof(int)*(num_arrays+a)); *(arrays[j]+a-1)=atoi(tutar[i]); printf("%d",arrays[1][1]); } arrays is pointer when you see x exit you see n create (old one is new array[a] new one is array[i+1]) you see d delete arrays[i] according to int after d first number is size of max arrays and where is the error in code input is composed from int and n d x i make a program -taking input(first input must be int) -according to input(there is comman in input like n or d or j , i fill array with number and use memory efficiently -j is jumb to array[x] ( x is int coming after j in input)

    Read the article

  • Efficient implementation of exclusive execution

    - by n0weak
    I have an ObjectManager class that is used to process payments. It is wrapped over the Order entities, so new instance has to be created when processing is required. I need to prevent the situation when several ObjectManager instances are dealing with the same order simultaneously (it happend once because of some errors on the remote payment processing center, somehow they called our callback urls twice). I'd love to get an advice how to implement it more efficiently. For now, I am thinking about something like that: public class OrderManager{ private static final CopyOnWriteArrayList<Integer> LOCKER = new CopyOnWriteArrayList<Integer>(); private static synchronized boolean tryLock(Integer key) { return LOCKER.addIfAbsent(key); } private static void releaseLock(Integer key) { LOCKER.remove(key); } public void processPayment(Integer orderId) throws Exception{ if (!tryLock(orderId)) { return; } try { //operate } finally { releaseLock(orderId); } } //remainder omitted }

    Read the article

  • What's the most efficient way to find barycentric coordinates?

    - by bobobobo
    In my profiler, finding barycentric coordinates is apparently somewhat of a bottleneck. I am looking to make it more efficient. It follows the method in shirley, where you compute the area of the triangles formed by embedding the point P inside the triangle. Code: Vector Triangle::getBarycentricCoordinatesAt( const Vector & P ) const { Vector bary ; // The area of a triangle is real areaABC = DOT( normal, CROSS( (b - a), (c - a) ) ) ; real areaPBC = DOT( normal, CROSS( (b - P), (c - P) ) ) ; real areaPCA = DOT( normal, CROSS( (c - P), (a - P) ) ) ; bary.x = areaPBC / areaABC ; // alpha bary.y = areaPCA / areaABC ; // beta bary.z = 1.0f - bary.x - bary.y ; // gamma return bary ; } This method works, but I'm looking for a more efficient one!

    Read the article

  • Would it be more efficient to handle 2D collision detection with polygons, rather than both squares/polygons?

    - by KleptoKat
    I'm working on a 2D game engine and I'm trying to get collision detection as efficient as possible. One thing I've noted is that I have a Rectangle Collision collider, a Shape (polygon) collider and a circle collider. Would it be more efficient (either dev-time wise or runtime wise) to have just one shape collider, rather than have that and everything else? I feel it would optimize my code in the back end, but how much would it affect my game at runtime? Should I be concerned with this at all, as 3D games generally have tens of thousands of polygons?

    Read the article

  • Is a blob more efficient than a varchar for data that can be ANY size?

    - by BillyNair
    When setting up a database I want to use the most efficient data type for potentially fairly long data. Currently my project is to store song titles and thoughts pertaining to that song. Some titles might be 5 characters or longer than 100 characters and the thoughts could run pretty long. Is it more efficient to use a varchar set to 8000 or to use a blob? Is using a blob the same as a varchar, in that there is a set size it is allocated regardless of what it holds? or is it just a pointer and it doesn't really use much space on the table? Is there a certain set size of a blob in KB or is it expandable?

    Read the article

< Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >