Search Results

Search found 6805 results on 273 pages for 'fast formula'.

Page 176/273 | < Previous Page | 172 173 174 175 176 177 178 179 180 181 182 183  | Next Page >

• SQL - query inside NOT IN takes longer than the complete query ??

  - by Aleksandar Tomic

  Hi every1, I'm using NOT IN inside my SQL query. For example: select columnA from table1 where columnA not in ( select columnB from table2) How is it possible that this part of the query select columnB from table2 takes 30sec to complete, but the whole query above takes 0.1sec to complete?? Shouldn't the complete query take 30sec + ? BTW, both queries return valid results. Thanks! Answers to Comments Is it because the second query hasn't actually completed but has only returned back the first 'x' rows (out of a very large table?) No, the query is completed after 30 seconds, not to many rows returned (eg. 50). But @Aleksandar wondered why the question congaing the performance killer was so fast. my point exactly Also how long does select distinct columnB from table2 take to execute? actually, the original query is "select distinct...

  Read the article

• Best XML Based Database

  - by monmonja

  I had been assigned to develop a system on where we would get a XML from multiple sources (millions of xml) and put them in some database like and judging from the xml i would receive, there wont be any concrete structure even if they are from the same source. With this reason i think i cannot suggest RDMS and currently looking at NoSQL databases. We need a system that could do CRUD and is fast on Read. I had been looking at MarkLogic and eXist, which are both XML based NoSQL databases, have anyone had experience with them? and any other suggestion? Thanks

  Read the article

• Ways to save enums in database

  - by corgrath

  Hey guys. I am wondering what the best ways to save enums into a database is. I know there are name() and valueOf() methods to make it into a String back. But are there any other (flexible) options to store these values? Is there a smart way to make them into unique numbers (ordinal() is not safe to use)? Any comments and suggestions would be helpful :) Update: Thanks for all awesome and fast answers! It was as I suspected. However a note to 'toolkit'; That is one way. The problem is that I would have to add the same methods with each enum type i create. Thats a lot of duplicated code and, at the moment, Java does not support any solutions to this (You cannot let enum extend other classes). However, thanks for all answers!

  Read the article

• Do you know a good and efficient FFT?

  - by yan bellavance

  Hi, I am trying to find a very fast and efficient Fourier transform (FFT). Does anyone know of any good ones. I need to run it on the iPhone so it must not be intensive. Instead, maybe you know of one that is wavelet like, i need frequency resolution but only a narrow band (vocal audio range up to 10khz max...even 10Khz might be too high). Im thinking also of truncating this FFT to keep the frequency resolution while eliminating the unwanted frequency band. This is for an iphone ...I have taken a look at the FFT in Aurio touch but it seems this is an int FFT but my app uses floats.....would it give a big performance increase to try and adapt program to an int FFT or not(which i really dont feel like doing...plus aurio touch uses a radix 2 FFT which is not that great).

  Read the article

• jQuery Cycle Plugin: How to preload first images with a loading background gif then fade in Cycle Sl

  - by Theo Ribeiro

  Hello all, I'm struggling with this, maybe some of you can help... I have a home page slideshow with large images at www.theoribeiro.com using jQuery Cycle plugin Images are large and sometimes with slow connections (but even in fast ones) the behavior of the slideshow start is pretty ugly, showing the image all of a sudden or half-loaded. I want to make sure that at least the 2 or 3 first images are loaded before the slideshow starts and meanwhile I want to run a loading animated gif, then I want to fade in the first image. I searched a lot on the internet and on the forums and tried loads of stuff with my limited knowledge of javascript and jQuery but could't come up with a solution. Any help would be greatly appreciated!!!

  Read the article

• c# binarysearch a list<T> by a member of T

  - by Pygmy

  I have a baseclass Event with a DateTime member TimeStamp. Lots of other event-classes will derive from this. I want to be able to search a list of events (that can contain events with duplicate timestamps) fast, so I'd like to use a binary search. So I started out writing something like this : public class EventList<T> : List<T> where T : Event { private IComparer<T> comparer = (x, y) => Comparer<DateTime>.Default.Compare(x.TimeStamp, y.TimeStamp); public IEnumerable<T> EventsBetween(DateTime inFromTime, DateTime inToTime) { // Find the index for the beginning. int index = this.BinarySearch(inFromTime, comparer); // BLAH REST OF IMPLEMENTATION } } The problem is that the BinarySearch only accepts T (so - an Event type) as parameter, while I want to search based on a member of T - the TimeStamp. What would be a good way to approach this ?

  Read the article

• jQuery show div click to hide then do not show again

  - by Jonny Wood

  I am using jQuery to hide a div on my page: $(document).ready(function(){ $('#message').hide(); When a certain part of the page scrolls into view the div shows using $(window).scroll(function() { var top = 0; top = $(window).scrollTop(); if((top >= 1000) && (top < 2000)){ $('#message').fadeIn('slow'); } } I want to add a close button to this as follows $('a#message-hide').click(function() { $('#message').hide('fast'); return false; All good so far but the part I cannot figure out is how to then STOP the div re-appearing when the user scrolls back to the trigger position on the page...?

  Read the article

• Are there such things as summer jobs for teenage programmers?

  - by Gbps

  I've taken programming as a hobby, studying it since I was 10 or so. 7 years to date, I've become progressivly good at C++, PHP, C#, Assembly, Lua, and the web languages such as HTML and CSS. Though I've never taken a class, I've been able to complete most, if not all of the questions from different "Programmer Interview Questions" articles and have participated in some small scale projects in the past. Summer starting yesterday for me, I've been thinking about how to keep busy while maybe earning some money along the way. Now, some kids mow lawns, others get fast food jobs, but what about programming jobs? Is there even such a thing?

  Read the article

• Finding intersection of two spheres

  - by Onkar Deshpande

  Hi, Consider the following problem - I am given 2 links of length L0 and L1. P0 is the point that the first link starts at and P1 is the point that I want the end of second link to be at in 3-D space. I am supposed to write a function that should take in these 3-D points (P0 and P1) as inputs and should find all configurations of the links that put the second link's end point at P1. My understanding of how to go about it is - Each link L0 and L1 will create a sphere S0 and S1 around itself. I should find out the intersection of those two spheres (which will be a circle) and print all points that are on the circumference of that circle. I saw gmatt's first reply on the http://stackoverflow.com/questions/1406375/finding-intersection-points-between-3-spheres but could not understand it properly since the images did not show up. I also saw a formula for finding out the intersection at mathworld[dot]wolfram[dot]com/Sphere-SphereIntersection[dot]html . I could find the radius of intersection by the method given on mathworld. Also I can find the center of that circle and then use the parametric equation of circle to find the points. The only doubt that I have is will this method work for the points P0 and P1 mentioned above ? Please comment and let me know your thoughts.

  Read the article

• PInvoke or using /clr:pure to compile

  - by Yin Zhu

  I have a set of numerical libraries in C++ and I want to call them interactively in a interpretive language like F# or IronPython. So I have two choices now: Compile the library in native DLL and use PInvoke to call functions in it. Compile the C++ library to .Net dll using visual c++ (/clr:pure compile option). The advantage of 1 is that it is very fast, however there are more work in it, e.g. I cannot PInvoke double pointer (e.g. float **), I must write another wrapper in the C++ library to make the interface friendly to .Net. The advantage of 2 is that I don't need to do know Mashaling strings, arrays, etc. However, the .net dll is slower compared to the native one. What others factors should be considered when choosing between the two?

  Read the article

• What's the best way to view/analyse/filter huge traces/logfiles?

  - by oliver

  this seems to be a reoccurring issue: we receive a bug report for our software and with it tons of traces or logfiles. since finding errors is much easier when having a visualization of the log messages/events over time it is convenient to use a tool that can display the progression of events in a graph etc. (e.g. wireshark (http://www.wireshark.org) for analyzing network traffic) what tool do you use for such a purpose? the problem with most tools i used so far is that they mercilessly break down when you feed them huge data traces ( 1GB) so some criteria for such a tool would be: can deal with huge input files ( 1 GB) is really fast (so you don't have to get coffee while a file is loading) has some sort of filtering mechanism

  Read the article

• (iPhone SDK) How to link instance variables to a specific UILabel

  - by Timbo

  I'm using the iPhone SDK to build a simple application. I've created a brand new class which has a single variable. I need to make 5 instances of that class, which I have no trouble doing. I can create those instances and also set the variables without issue. What i do need to know is this: How do I link each of the 5 different instances of the variable to different and specific UILabels? Would I be better to create a method that dynamically creates and positions the labels? Thanks for your help in advance, I'm now to this iphone programming thing. I'm serious about learning fast though so I have posted a bounty on this question here : http://www.askearn.com/Responses.aspx?QuestionID=6542613f-7be8-4bb3-a950-aac218d47711

  Read the article

• Calculating bounding grid coordinates to a user click on google maps/google earth

  - by user170304

  Hello, I have a requirement to calculate the centroid or geodesic midpoint of when a user clicks in between the lat/long grid crossing. The crossing forms a square in most parts of GE and sometimes elongated rectangles. This is due to the shape of the earth of course. I'm looking for a valid mathematical formula that would allow a user to click anywhere in between this grid and then an accurate function (in Javascript or server side code) that would take an assumed grid resolution (say 1km intervals for this discussion) and the input coordinates that should return a centroid coordinate within that graticule grid. To clarify please take a look at the attached image to my google group post: http://google-earth-api.googlegroups.com/web/Picture+5.png?gda=h5oFPz8AAAD315KpovipQeBwdfGpmW3ZhBc9PTADwYa-n193hZ6AItFmHuno63c7phcEXYVuRA6ccyFKn-rNKC-d1pM%5FIdV0&gsc=sz6bbAsAAABBKF7YXWYyc4GmXg-QruHj What I need to be able to do is if a user clicks anywhere in this grid square, I need to find the centroid or center point of that grid intersection/square or at least the bounding grid coordinates (that make the square). If we assume that the grid is UTM standard and has a max resolution of 1km (or make this a parameter), I need to detect the four other points nearby and then calculating the centroid is not as difficult. I welcome any feedback you all may have and appreciate it. I don't have a simple way of letting a user click anywhere on the grid and finding the grid bounding coordinates (making a square of 4 coordinates) or the centroid / midpoint of the graticule grid square necessary. One thought is to use assumptions as much as possible using a reference such as UTM coordinate reference. If I assume that the grid is X degrees wide, can we have a pure javascript function take any input coordinate and return for me the bounding graticule coordinates in Decimal Degrees? Another thought I had was to create the grid in a geo-spatial layer to take any input coordinate and return the nearest centroid of the graticule? Does this make sense? Thanks! Omar

  Read the article

• Cannot access a web page? [closed]

  - by ipkiss

  Hello all, Recently, I could not access the webpage bbc.co.uk anymore, while I can access other websites smoothly. Ar first, I though there may be some problem with my laptop. However, if I use my laptop through my company network, I can load the page bbc.co.uk normally. Then, I though maybe my ADSL at home blocks that web address. However, I tried another laptop with my home ADSL and it can load the page bbc.co.uk very fast. Now I do not know what could be the problem. Can anyone tell me please? Thank you.

  Read the article

• Effective Android Programming Techniques

  - by kunjaan

  Please Help me compile a list of Effective Android Programming techniques Don't forget to free resources after use. Lot of resources like Cursors are overlooked. Free them too. Don't Use magic Numbers. values[0] is meaningless. The framework provides very useful accessors like values[SensorManager.DATA_X] "Make use of onPause()/onResume to save or close what does not need to be opened the whole time." protected void onResume() { mSensorManager.registerListener(...); } protected void onStop() { mSensorManager.unregisterListener(...); super.onStop(); } Make your Android UI Fast and Efficient from the Google I/O has a lot of useful UI Performance tips.

  Read the article

• What is the best API/framework/platform you ever worked with?

  - by Yuval A

  Most programming is done on an existing framework or platform, and using various APIs which make your programming job much more convenient. It can either be a superbly designed set of APIs, or a nice framework which you managed to get really cool things done really fast. All answers should give concrete examples of why that framework is so awesome, or examples of cool stuff you did with it. What existing framework really inspired you to do some awesome work? I know this is subjective, but I think we can get some cool ideas from this question. Please be easy on the "close" link :) Also - commun-ikified in advance.

  Read the article

• Object tree navigation language in Java

  - by lewap

  In the system which I'm currently developing I often have to navigate an object tree and based on its state and values take actions. In normal Java this results in tedious for loops, if statements etc... Are there alternative ways to achieve tree navigation, similar to XPath for XML? I know there is JXPath and OGNL, but do you know any other libraries for such purpose? Do you know any libraries which generate bytecodes for specific tree navigation expressions to make the processing as fast as Java native fors and ifs?

  Read the article

• Sql server table can be queried but not updated

  - by Nigel

  i have a table which was always updatable before, but then suddenly i can no longer update the any of the columns in the table. i can still query the whole table and the results come back very fast, but the moment i try to update a column in the table, the update query simply stalls and does nothing. i tried using select req_transactionUOW from master..syslockinfo where req_spid = -2 to see if some orphaned transaction was locking the table, but it returns no results. i can't seems to find signs of my table being locked, but simply cannot update it. any clues as to how to fix the table or whatever state it is in?

  Read the article

• How to do a sample rate conversion in Windows (and OSX)

  - by Paperflyer

  I am about to write an audio file converter for my side job at the university. As part of this I would need sample rate conversion. However, my professor said that it would be pretty hard to write a sample rate converter that was both of good quality and fast. On my research on the subject, I found some functions in the OSX CoreAudio-framework, that could do a sample rate conversion (AudioConverter.h). After all, an OS has to have some facilities to do that for its own audio stack. Do you know a similar method for C/C++ and Windows, that are either part of the OS or open source? I am pretty sure that this function exists within DirectX Audio (XAudio2?), but I seem to be unable to find a reference to it in the MSDN library.

  Read the article

• How safe am I signing into Google Spreadsheets with yeroon.net/ggplot2

  - by Farrel

  I am impressed by what I have seen of yeroon.net/ggplot2 which is a web interface for Hadley Wickham's R package ggplot2. I want to try it out on my own data. The part that has me very excited is that one can use data stored in one's own Google spreadsheet as the data. One just signs into their Google Account so that yeroon.net/ggplot2 can access the spreadsheet list. I have been hesitant to do it. If I sign in whilst on yeroon.net am I handing over my username and password to a third party? It would not be wise of me to divulge my google password to third parties since Google is fast becoming my repository of everything. How do I know if Jeroon's application is using ClientLogin or OAuth? My understanding is very basic and may be wrong but nevertheless here it is. OAuth would be better since it does not actually pass the password onto the third party application.

  Read the article

• NFS Server in Java

  - by dmeister

  I search an implementation of a network (or distributed) file system like NFS in Java. The goal is to extend it and do some research stuff with it. On the web I found some implementation e.g. DJ NFS, but the open question is how mature and fast they are. Can anyone purpose a good starting point, has anyone experience with such things? P.S. I know Hadoop DFS and I used it for some projects, but Hadoop is not a good fit for the things I want to do here. --EDIT-- Hadoop is really focused on highly scalable, high throughput computing without the possibilities to overwrite parts of a file and so an. The goal is you could use the filesystem e.g. for user home directories. --EDIT-- More Details: The idea is to modify such a implementation so that the files are not stored directly on a local filesystem, but to apply data de-duplication.

  Read the article

• How to improve INSERT INTO ... SELECT locking behavior

  - by Artem

  In our production database, we ran the following pseudo-code SQL batch query running every hour: INSERT INTO TemporaryTable (SELECT FROM HighlyContentiousTableInInnoDb WHERE allKindsOfComplexConditions are true) Now this query itself does not need to be fast, but I noticed it was locking up HighlyContentiousTableInInnoDb, even though it was just reading from it. Which was making some other very simple queries take ~25 seconds (that's how long that other query takes). Then I discovered that InnoDB tables in such a case are actually locked by a SELECT! http://www.mysqlperformanceblog.com/2006/07/12/insert-into-select-performance-with-innodb-tables/ But I don't really like the solution in the article of selecting into an OUTFILE, it seems like a hack (temporary files on filesystem seem sucky). Any other ideas? Is there a way to make a full copy of an InnoDB table without locking it in this way during the copy. Then I could just copy the HighlyContentiousTable to another table and do the query there.

  Read the article

• Transfer files using java

  - by markovuksanovic

  I need to transfer lots of small files to a remote computer within my java program. I was wondering if somebody could suggest the best way to do so... I need to transfer lots of small files and it has to be really fast. Should I use some existing protocol implementation? maybe ftp? One important thing is that most files would be the same all the time, or the difference would be minor so I was thinking of using git for that purpose. Does anyone have experience with sth like this?

  Read the article

• Most efficient way to solve system of equations involving the digamma function?

  - by Neil G

  What is the most efficient way to solve system of equations involving the digamma function? I have a vector v and I want to solve for a vector w such that for all i: digamma(sum(w)) - digamma(w_i) = v_i and w_i 0 I found the gsl function gsl_sf_psi, which is the digamma function. Is there an identity I can use to reduce the equations? Is my best bet to use a solver? I am using C++0x; which solver is easiest to use and fast?

  Read the article

• 2D Spaceship movement math

  - by YAS

  Hi, I'm new here. I'm trying to make a top-down spaceship game and I want the movement to somewhat realistic. 360 degrees with inertia, gravity, etc. My problem is I can make the ship move 360 with inertia with no problem, but what I need to do is impose a limit for how fast the engines can go while not limiting other forces pushing/pulling the ship. So, if the engines speed is a maximum of 500 and the ship is going 1000 from a gravity well, the ship is not going to go 1500 when it's engines are on, but if is pointing away from the angle is going then it could slow down. For what it's worth, I'm using Construct (www.scirra.com), and all I need is the math of it. Thanks for any help, I'm going bald from trying to figure this out.

  Read the article

< Previous Page | 172 173 174 175 176 177 178 179 180 181 182 183  | Next Page >