Search Results

Search found 14861 results on 595 pages for 'high speed computing'.

Page 524/595 | < Previous Page | 520 521 522 523 524 525 526 527 528 529 530 531  | Next Page >

• Lookup table size reduction

  - by Ryan

  Hello: I have an application in which I have to store a couple of millions of integers, I have to store them in a Look up table, obviously I cannot store such amount of data in memory and in my requirements I am very limited I have to store the data in an embebedded system so I am very limited in the space, so I would like to ask you about recommended methods that I can use for the reduction of the look up table. I cannot use function approximation such as neural networks, the values needs to be in a table. The range of the integers is not known at the moment. When I say integers I mean a 32 bit value. Basically the idea is use some copmpression method to reduce the amount of memory but without losing many precision. This thing needs to run in hardware so the computation overhead cannot be very high. In my algorithm I have to access to one value of the table do some operations with it and after update the value. In the end what I should have is a function which I pass an index to it and then I get a value, and after I have to use another function to write a value in the table. I found one called tile coding http://www.cs.ualberta.ca/~sutton/book/8/node6.html, this one is based on several look up tables, does anyone know any other method?. Thanks.

  Read the article

• java GC periodically enters into several full GC cycles

  - by Peter

  Environment: sun JDK 1.6.0_16 vm settings: -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -Xms1024 -Xmx1024M -XX:MaxNewSize=448m -XX:NewSize=448m -XX:SurvivorRatio=4(6 also checked) -XX:MaxPermSize=128M OS: windows server 2003 processor: 4 cores of INTEL XEON 5130, 2000 Hz my application description: high intensity of concurrent(java 5 concurrency used) operations completed each time by commit to oracle. it's about 20-30 threads run non stop, doing tasks. application runs in JBOSS web container. My GC starts work normally, I see a lot of small GCs and all that time CPU shows good load, like all 4 cores loaded to 40-50%, CPU graph is stable. Then , after 1 min of good work, CPU starts drop to 0% on 2 cores from 4, it's graph becomes unstable, goes up and down("teeth"). I see, that my threads work slower(I have monitoring), I see that GC starts produce a lot of FULL GC during that time and next 4-5 minutes this situation remains as is, then for short period of time, like 1 minute, it gets back to normal situation, but shortly after that all bad thing repeats. Question: Why I have so frequent full GC??? How to prevent that? I played with SurvivorRatio - does not help. I noticed, that application behaves normally until first FULL GC occurs, while I have enough memory. Then it runs badly. my GC LOG: starts good then long period of FULL GCs(many of them) 1027.861: [GC 942200K-623526K(991232K), 0.0887588 secs] 1029.333: [GC 803279K(991232K), 0.0927470 secs] 1030.551: [GC 967485K-625549K(991232K), 0.0823024 secs] 1030.634: [GC 625957K(991232K), 0.0763656 secs] 1033.126: [GC 969613K-632963K(991232K), 0.0850611 secs] 1033.281: [GC 649899K(991232K), 0.0378358 secs] 1035.910: [GC 813948K(991232K), 0.3540375 secs] 1037.994: [GC 967729K-637198K(991232K), 0.0826042 secs] 1038.435: [GC 710309K(991232K), 0.1370703 secs] 1039.665: [GC 980494K-972462K(991232K), 0.6398589 secs] 1040.306: [Full GC 972462K-619643K(991232K), 3.7780597 secs] 1044.093: [GC 620103K(991232K), 0.0695221 secs] 1047.870: [Full GC 991231K-626514K(991232K), 3.8732457 secs] 1053.739: [GC 942140K(991232K), 0.5410483 secs] 1056.343: [Full GC 991232K-634157K(991232K), 3.9071443 secs] 1061.257: [GC 786274K(991232K), 0.3106603 secs] 1065.229: [Full GC 991232K-641617K(991232K), 3.9565638 secs] 1071.192: [GC 945999K(991232K), 0.5401515 secs] 1073.793: [Full GC 991231K-648045K(991232K), 3.9627814 secs] 1079.754: [GC 936641K(991232K), 0.5321197 secs]

  Read the article

• Wrappers of primitive types in arraylist vs arrays

  - by ismail marmoush

  Hi, In "Core java 1" I've read CAUTION: An ArrayList is far less efficient than an int[] array because each value is separately wrapped inside an object. You would only want to use this construct for small collections when programmer convenience is more important than efficiency. But in my software I've already used Arraylist instead of normal arrays due to some requirements, though "The software is supposed to have high performance and after I've read the quoted text I started to panic!" one thing I can change is changing double variables to Double so as to prevent auto boxing and I don't know if that is worth it or not, in next sample algorithm public void multiply(final double val) { final int rows = getSize1(); final int cols = getSize2(); for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { this.get(i).set(j, this.get(i).get(j) * val); } } } My question is does changing double to Double makes a difference ? or that's a micro optimizing that won't affect anything ? keep in mind I might be using large matrices.2nd Should I consider redesigning the whole program again ?

  Read the article

• Calling DI Container directly in method code (MVC Actions)

  - by fearofawhackplanet

  I'm playing with DI (using Unity). I've learned how to do Constructor and Property injection. I have a static container exposed through a property in my Global.asax file (MvcApplication class). I have a need for a number of different objects in my Controller. It doesn't seem right to inject these throught the constructor, partly because of the high quantity of them, and partly because they are only needed in some Actions methods. The question is, is there anything wrong with just calling my container directly from within the Action methods? public ActionResult Foo() { IBar bar = (Bar)MvcApplication.Container.Resolve(IBar); // ... Bar uses a default constructor, I'm not actually doing any // injection here, I'm just telling my conatiner to give me Bar // when I ask for IBar so I can hide the existence of the concrete // Bar from my Controller. } This seems the simplest and most efficient way of doing things, but I've never seen an example used in this way. Is there anything wrong with this? Am I missing the concept in some way?

  Read the article

• How to eliminate tearing from animation?

  - by MusiGenesis

  I'm running an animation in a WinForms app at 18.66666... frames per second (it's synced with music at 140 BPM, which is why the frame rate is weird). Each cel of the animation is pre-calculated, and the animation is driven by a high-resolution multimedia timer. The animation itself is smooth, but I am seeing a significant amount of "tearing", or artifacts that result from cels being caught partway through a screen refresh. When I take the set of cels rendered by my program and write them out to an AVI file, and then play the AVI file in Windows Media Player, I do not see any tearing at all. I assume that WMP plays the file smoothly because it uses DirectX (or something else) and is able to synchronize the rendering with the screen's refresh activity. It's not changing the frame rate, as the animation stays in sync with the audio. Is this why WMP is able to render the animation without tearing, or am I missing something? Is there any way I can use DirectX (or something else) in order to enable my program to be aware of where the current scan line is, and if so, is there any way I can use that information to eliminate tearing without actually using DirectX for displaying the cels? Or do I have to fully use DirectX for rendering in order to deal with this problem? Update: forgot a detail. My app renders each cell onto a PictureBox using Graphics.DrawImage. Is this significantly slower than using BitBlt, such that I might eliminate at least some of the tearing by using BitBlt?

  Read the article

• Building Stored Procedure to group data into ranges with roughly equal results in each bucket

  - by Len

  I am trying to build one procedure to take a large amount of data and create 5 range buckets to display the data. the buckets ranges will have to be set according to the results. Here is my existing SP GO /****** Object: StoredProcedure [dbo].[sp_GetRangeCounts] Script Date: 03/28/2010 19:50:45 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE [dbo].[sp_GetRangeCounts] @idMenu int AS declare @myMin decimal(19,2), @myMax decimal(19,2), @myDif decimal(19,2), @range1 decimal(19,2), @range2 decimal(19,2), @range3 decimal(19,2), @range4 decimal(19,2), @range5 decimal(19,2), @range6 decimal(19,2) SELECT @myMin=Min(modelpropvalue), @myMax=Max(modelpropvalue) FROM xmodelpropertyvalues where modelPropUnitDescriptionID=@idMenu set @myDif=(@myMax-@myMin)/5 set @range1=@myMin set @range2=@myMin+@myDif set @range3=@range2+@myDif set @range4=@range3+@myDif set @range5=@range4+@myDif set @range6=@range5+@myDif select @myMin,@myMax,@myDif,@range1,@range2,@range3,@range4,@range5,@range6 select t.range as myRange, count(*) as myCount from ( select case when modelpropvalue between @range1 and @range2 then 'range1' when modelpropvalue between @range2 and @range3 then 'range2' when modelpropvalue between @range3 and @range4 then 'range3' when modelpropvalue between @range4 and @range5 then 'range4' when modelpropvalue between @range5 and @range6 then 'range5' end as range from xmodelpropertyvalues where modelpropunitDescriptionID=@idmenu) t group by t.range order by t.range This calculates the min and max value from my table, works out the difference between the two and creates 5 buckets. The problem is that if there are a small amount of very high (or very low) values then the buckets will appear very distorted - as in these results... range1 2806 range2 296 range3 75 range5 1 Basically I want to rebuild the SP so it creates buckets with equal amounts of results in each. I have played around with some of the following approaches without quite nailing it... SELECT modelpropvalue, NTILE(5) OVER (ORDER BY modelpropvalue) FROM xmodelpropertyvalues - this creates a new column with either 1,2,3,4 or 5 in it ROW_NUMBER()OVER (ORDER BY modelpropvalue) between @range1 and @range2 ROW_NUMBER()OVER (ORDER BY modelpropvalue) between @range2 and @range3 or maybe i could allocate every record a row number then divide into ranges from this?

  Read the article

• TextField Covering UIAlertView's Button.

  - by XcodeDev

  Hi, I am using a UIAlertView with three buttons: "Dismiss", "Submit Score" and @"View Leaderboard". The UIAlertView also contains a UITextField called username. At the moment the UITextField "username" is covering one of the buttons in the UIAlertView. I just wanted to know how I could stop the UITextField from covering one of the buttons, i.e move the buttons down. Here is an image of what is happening: And here is my code: [username setBackgroundColor:[UIColor whiteColor]]; [username setBorderStyle:UITextBorderStyleRoundRect]; username.backgroundColor = [UIColor clearColor]; username.returnKeyType = UIReturnKeyDone; username.keyboardAppearance = UIKeyboardAppearanceAlert; username.placeholder = @"Enter your name here"; username = [[UITextField alloc] initWithFrame:CGRectMake(20.0, 45.0, 245.0, 25.0)]; username.borderStyle = UITextBorderStyleRoundedRect; [username resignFirstResponder]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Congratulations" message:[NSString stringWithFormat:@"You tapped %i times in %i seconds!\n", tapAmount, originalCountdownTime] delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:@"Submit To High Score Leaderboard", @"View Leaderboard", nil]; alert.tag = 01; [alert addSubview:username]; [alert show]; [alert release];

  Read the article

• best practice - loging events (general) and changes (database)

  - by b0x0rz

  need help with logging all activities on a site as well as database changes. requirements: * should be in database * should be easily searchable by initiator (user name / session id), event (activity type) and event parameters i can think of a database design but either it involves a lot of tables (one per event) so i can log each of the parameters of an event in a separate field OR it involves one table with generic fields (7 int numeric and 7 text types) and log everything in one table with event type field determining what parameter got written where (and hoping that i don't need more than 7 fields of a certain type, or 8 or 9 or whatever number i choose)... example of entries (the usual things): [username] login failed @datetime [username] login successful @datetime [username] changed password @datetime, estimated security of password [low/ok/high/perfect] @datetime [username] clicked result [result number] [result id] after searching for [search string] and got [number of results] @datetime [username] clicked result [result number] [result id] after searching for [search string] and got [number of results] @datetime [username] changed profile name from [old name] to [new name] @datetime [username] verified name with [credit card type] credit card @datetime datbase table [table name] purged of old entries @datetime etc... so anyone dealt with this before? any best practices / links you can share? i've seen it done with the generic solution mentioned above, but somehow that goes against what i learned from database design, but as you can see the sheer number of events that need to be trackable (each user will be able to see this info) is giving me headaches, BUT i do LOVE the one event per table solution more than the generic one. any thoughts? edit: also, is there maybe an authoritative list of such (likely) events somewhere? thnx stack overflow says: the question you're asking appears subjective and is likely to be closed. my answer: probably is subjective, but it is directly related to my issue i have with designing a database / writing my code, so i'd welcome any help. also i tried narrowing down the ideas to 2 so hopefully one of these will prevail, unless there already is an established solution for these kinds of things.

  Read the article

• Best practice - logging events (general) and changes (database)

  - by b0x0rz

  need help with logging all activities on a site as well as database changes. requirements: * should be in database * should be easily searchable by initiator (user name / session id), event (activity type) and event parameters i can think of a database design but either it involves a lot of tables (one per event) so i can log each of the parameters of an event in a separate field OR it involves one table with generic fields (7 int numeric and 7 text types) and log everything in one table with event type field determining what parameter got written where (and hoping that i don't need more than 7 fields of a certain type, or 8 or 9 or whatever number i choose)... example of entries (the usual things): [username] login failed @datetime [username] login successful @datetime [username] changed password @datetime, estimated security of password [low/ok/high/perfect] @datetime [username] clicked result [result number] [result id] after searching for [search string] and got [number of results] @datetime [username] clicked result [result number] [result id] after searching for [search string] and got [number of results] @datetime [username] changed profile name from [old name] to [new name] @datetime [username] verified name with [credit card type] credit card @datetime datbase table [table name] purged of old entries @datetime via automated process etc... so anyone dealt with this before? any best practices / links you can share? i've seen it done with the generic solution mentioned above, but somehow that goes against what i learned from database design, but as you can see the sheer number of events that need to be trackable (each user will be able to see this info) is giving me headaches, BUT i do LOVE the one event per table solution more than the generic one. any thoughts? edit: also, is there maybe an authoritative list of such (likely) events somewhere? thnx stack overflow says: the question you're asking appears subjective and is likely to be closed. my answer: probably is subjective, but it is directly related to my issue i have with designing a database / writing my code, so i'd welcome any help. also i tried narrowing down the ideas to 2 so hopefully one of these will prevail, unless there already is an established solution for these kinds of things.

  Read the article

• Cross-Platform Camera API

  - by Karim

  Hi, I'm now building a video transforming filter that have to transform video frames in real-time. One of the key requirements of the filter is to have high performance to minimize the number of dropped frames during the transform. Another requirement that is of lower priority but also nice to have is to make it cross-platform (both PC's and Mobile devices). The application is built in C++. Now my question is: is there any API that is more portable and has a similar or better performance characteristics than DirectShow? as DirectShow's portability is only limited to Windows-based devices (PCs and Windows Mobile&CE platforms). Also I've notices that for example using HTC's custom camera API has far better performance than what DirectShow offers. If you want to check this, try to build a filter in DirectShow that will multiply each color by 2 and render that in real-time from camera on the screen. Then do the same with HTC's API. There is almost 4-5x performance boost with vendor's specific API. So it'd be very nice if the library used the device-specific implementation of the driver, as performance is critical when doing this transforms on a mobile device (which is about ~500 MHz).

  Read the article

• How to index a table with a Type 2 slowly changing dimension for optimal performance

  - by The Lazy DBA

  Suppose you have a table with a Type 2 slowly-changing dimension. Let's express this table as follows, with the following columns: * [Key] * [Value1] * ... * [ValueN] * [StartDate] * [ExpiryDate] In this example, let's suppose that [StartDate] is effectively the date in which the values for a given [Key] become known to the system. So our primary key would be composed of both [StartDate] and [Key]. When a new set of values arrives for a given [Key], we assign [ExpiryDate] to some pre-defined high surrogate value such as '12/31/9999'. We then set the existing "most recent" records for that [Key] to have an [ExpiryDate] that is equal to the [StartDate] of the new value. A simple update based on a join. So if we always wanted to get the most recent records for a given [Key], we know we could create a clustered index that is: * [ExpiryDate] ASC * [Key] ASC Although the keyspace may be very wide (say, a million keys), we can minimize the number of pages between reads by initially ordering them by [ExpiryDate]. And since we know the most recent record for a given key will always have an [ExpiryDate] of '12/31/9999', we can use that to our advantage. However... what if we want to get a point-in-time snapshot of all [Key]s at a given time? Theoretically, the entirety of the keyspace isn't all being updated at the same time. Therefore for a given point-in-time, the window between [StartDate] and [ExpiryDate] is variable, so ordering by either [StartDate] or [ExpiryDate] would never yield a result in which all the records you're looking for are contiguous. Granted, you can immediately throw out all records in which the [StartDate] is greater than your defined point-in-time. In essence, in a typical RDBMS, what indexing strategy affords the best way to minimize the number of reads to retrieve the values for all keys for a given point-in-time? I realize I can at least maximize IO by partitioning the table by [Key], however this certainly isn't ideal. Alternatively, is there a different type of slowly-changing-dimension that solves this problem in a more performant manner?

  Read the article

• using linq to sql

  - by mazhar

  Well I am new to this orm stuff. We have to create a large project . I read about linq to sql . will it be appropiate to use it in the project of high risk . i found no problem with it personally but the thing is that there will be no going back once started.So i need some feedback from the orm gurus here at the msdn.Will entity framework will be better?( I am in doubt about link to sql because I have read and heard negative feedback here and there) I will be using mvc2 as the framework. So please give the feedback about linq to sql in this regard. q2) Also I am a fan of stored procedure as they are precomputed and fasten up the thing and I have never worked without them.I know that linq to sql support stored procedures but will it be feasible to give up stored procedure seeing the beautiful data access layer generated with little effort as we are also in a need of rapid development. q3) If some changes to some fields required in the database in Link to Sql how will the changes be accommodated in the data access layer.

  Read the article

• using linq to sql

  - by user324831

  Well I am new to this orm stuff. We have to create a large project . I read about linq to sql . will it be appropiate to use it in the project of high risk . i found no problem with it personally but the thing is that there will be no going back once started.So i need some feedback from the orm gurus here at the msdn.Will entity framework will be better?( I am in doubt about link to sql because I have read and heard negative feedback here and there) I will be using mvc2 as the framework. So please give the feedback about linq to sql in this regard. q2) Also I am a fan of stored procedure as they are precomputed and fasten up the thing and I have never worked without them.I know that linq to sql support stored procedures but will it be feasible to give up stored procedure seeing the beautiful data access layer generated with little effort as we are also in a need of rapid development. q3) If some changes to some fields required in the database in Link to Sql how will the changes be accommodated in the data access layer.

  Read the article

• What is the best way to detect white color?

  - by dnul

  I'm trying to detect white objects in a video. The first step is to filter the image so that it leaves only white-color pixels. My first approach was using HSV color space and then checking for high level of VAL channel. Here is the code: //convert image to hsv cvCvtColor( src, hsv, CV_BGR2HSV ); cvCvtPixToPlane( hsv, h_plane, s_plane, v_plane, 0 ); for(int x=0;x<srcSize.width;x++){ for(int y=0;y<srcSize.height;y++){ uchar * hue=&((uchar*) (h_plane->imageData+h_plane->widthStep*y))[x]; uchar * sat=&((uchar*) (s_plane->imageData+s_plane->widthStep*y))[x]; uchar * val=&((uchar*) (v_plane->imageData+v_plane->widthStep*y))[x]; if((*val>170)) *hue=255; else *hue=0; } } leaving the result in the hue channel. Unfortunately, this approach is very sensitive to lighting. I'm sure there is a better way. Any suggestions?

  Read the article

• How does someone without a CS degree get an interview in a sluggish economy?

  - by Anon

  I've been programming off and on since 4th grade (for about 20 years). Technology is one of my passions but after working in the field for a couple years out of High School, I spent nine months and $15,000 getting an accredited certificate in music performance instead of CS. I've been doing lots of self study but I think a CS degree is overkill for most line of business applications. Even so, HR departments can't be expected to know that... How does one get their foot in the proverbial door without a degree, especially in a smaller "fly-over country" market? ...or... Where can I get the cheapest/easiest degree that will pass muster (including testing out of as much as possible)? Don't get me wrong, I'm down with learning new things but I don't necessarily need the expense or coaching to motivate me. EDIT Consolidating good answers: Networking/User Groups Portfolio/Open Source Contributions Look for hybrid jobs (How I got my start :) ) Seek un-elitist companies/hiring managers. (Play the numbers game) Start my own business. (This is a bit challenging for a family man but a very good answer. My reason for searching is to reduce my commute thereby allowing more time to cultivate income on the side) Avail myself of political subsidies to constituents in the teachers' unions ;) .

  Read the article

• How should a process running outside Internet Explorer talk to JavaScript running inside it?

  - by Paul Crowley

  This may well be impossible; either way I'm sure people here will know. I'm trying to reduce three "OK" prompts to two. As part of my application, users will download and run an executable I supply; call it privileged.exe. privileged.exe will have a coda that asks for the highest privileges available. That's two OK prompts, one to run privileged.exe and one for UAC. I'd like privileged.exe to then install an ActiveX control, browser plugin or some such. The purpose of this ActiveX control is to allow the JavaScript running inside the browser to talk to the running privileged.exe process, to allow the user to perform certain operations that require high privileges by making choices in the browser. And I'd ideally like this to happen without the user having to restart their browser or explicitly OK the installation of the ActiveX control. Is that possible? Can you install an ActiveX control from outside the browser in such a way that it becomes immediately available to pages running inside the browser? Or should I give up, and allow the user to be explicitly prompted to install the ActiveX control?

  Read the article

• Exposed onsite vs IFD deployments for MS Dynamics CRM

  - by Greg McGuffey

  I'm working for the first time on a MS Dyanmics CRM 4.0 project. Our company has a high number of remote employees and even more remote consultants. As such it will be necessary to make the CRM solution available over the internet. As near as I can tell, I have three options: Have everyone use a VPN to access an intranet site (typical onsite deployment). However, we have found that VPNs are far from trouble free and cause many support issues. We avoid them like the plague. Use IFD to expose the CRM on the internet. I don't know much about this except that the URL will be different than the onsite URL, which could cause some headaches (see below). Expose the CRM site by opening the site to the internet, using SSL to encrypt traffic. We currently do this with our MS sharepoint sites. I'm not sure how secure this would be (one of the reasons for this question). I'd like to avoid using both the onsite intranet deployment and the IFD together for a couple of reasons. One of the requests for the solution is use email to notify users that they've been assigned a task, and include the URL to the task within the email. For this reason. If both deployments are used, then I'll need to include two URLs and the user would need to know which to use. Which leads to the second reason, the main users of the solution split time between being in the office and being remote. Thus they would need to access the solution two different ways, and know when to use which. Bad. So, what are the advantages/disadvantages of any of these methods? Any other options? Is there any issue using IFD from within the intranet? Security issues? Thanks!

  Read the article

• Calculate location and number of intersections between multiple date/time ranges?

  - by Patricker

  I need to calculate the location of intersections between multiple date ranges, and the number of overlapping intersections. Then I need to show which date/time ranges overlap each of those intersecting sections. It is slightly more complicated than that so I'll do my best to explain by providing an example. I am working in VB.Net, but C# examples are acceptable as well as I work in both. We have several high risk tasks that involve the same system. Below I have three example jobs named HR1/2/3/4 with start and end date/times. HR1 {1/6/2010 10:00 - 1/6/2010 15:00} HR2 {1/6/2010 11:00 - 1/6/2010 18:00} HR3 {1/6/2010 12:00 - 1/6/2010 14:00} HR4 {1/6/2010 18:00 - 1/6/2010 20:00} What I want the end result to be is shown below. I am having trouble describing it any way but by example. HRE1 {1/6/2010 10:00 - 1/6/2010 11:00} - Intersects 1 {End Time Split 1, for readability only, not needed in solution} HRE1 {1/6/2010 11:00 - 1/6/2010 12:00} - Intersects 2 HRE2 {1/6/2010 11:00 - 1/6/2010 12:00} - Intersects 2 {End Time Split 2, for readability only, not needed in solution} HRE1 {1/6/2010 12:00 - 1/6/2010 14:00} - Intersects 3 HRE2 {1/6/2010 12:00 - 1/6/2010 14:00} - Intersects 3 HRE3 {1/6/2010 12:00 - 1/6/2010 14:00} - Intersects 3 {End Time Split 3, for readability only, not needed in solution} HRE1 {1/6/2010 14:00 - 1/6/2010 15:00} - Intersects 2 HRE2 {1/6/2010 14:00 - 1/6/2010 15:00} - Intersects 2 {End Time Split 4, for readability only, not needed in solution} HRE2 {1/6/2010 15:00 - 1/6/2010 18:00} - Intersects 1 {End Time Split 5, for readability only, not needed in solution} HR4 {1/6/2010 18:00 - 1/6/2010 20:00} - Intersects 1 Any help would be greatly appreciated.

  Read the article

• Reading Unicode files line by line C++

  - by Roger Nelson

  What is the correct way to read Unicode files line by line in C++? I am trying to read a file saved as Unicode (LE) by Windows Notepad. Suppose the file contains simply the characters A and B on separate lines. In reading the file byte by byte, I see the following byte sequence (hex) : FE FF 41 00 0D 00 0A 00 42 00 0D 00 0A 00 So 2 byte BOM, 2 byte 'A', 2byte CR , 2byte LF, 2 byte 'B', 2 byte CR, 2 byte LF . I tried reading the text file using the following code: std::wifstream file("test.txt"); file.seekg(2); // skip BOM std::wstring A_line; std::wstring B_line; getline(file,A_line); // I get "A" getline(file,B_line); // I get "\0B" I get the same results using operator instead of getline file >> A_line; file >> B_line; It appears that the single byte CR character is is being consumed only as the single byte. or CR NULL LF is being consumed but not the high byte NULL. I would expect wifstream in text mode would read the 2byte CR and 2byte LF. What am I doing wrong? It does not seem right that one should have to read a text file byte by byte in binary mode just to parse the new lines.

  Read the article

• How many users are sufficient to make a heavy load for web application

  - by galymzhan

  I have a web application, which has been suffering high load recent days. The application runs on single server which has 8-core Intel CPU and 4gb of RAM. Software: Drupal 5 (Apache 2, PHP5, MySQL5) running on Debian. After reaching 500 authenticated and 200 anonymous users (simultaneous), the application drastically decreases its performance up to total failure. The biggest load comes from authenticated users, who perform activities, causing insert/update/deletes on db. I think mysql is a bottleneck. Is it normal to slow down on such number of users? EDIT: I forgot to mention that I did some kind of profiling. I runned commands top, htop and they showed me that all memory was being used by MySQL! After some time MySQL starts to perform terribly slow, site goes down, and we have to restart/stop apache to reduce load. Administrators said that there was about 200 active mysql connections at that moment. The worst point is that we need to solve this ASAP, I can't do deep profiling analysis/code refactoring, so I'm considering 2 ways: my tables are MyIsam, I heard they use table-level locking which is very slow, is it right? could I change it to Innodb without worry? what if I take MySQL, and move it to dedicated machine with a lot of RAM?

  Read the article

• forcing stack w/i 32bit when -m64 -mcmodel=small

  - by chaosless

  have C sources that must compile in 32bit and 64bit for multiple platforms. structure that takes the address of a buffer - need to fit address in a 32bit value. obviously where possible these structures will use natural sized void * or char * pointers. however for some parts an api specifies the size of these pointers as 32bit. on x86_64 linux with -m64 -mcmodel=small tboth static data and malloc()'d data fit within the 2Gb range. data on the stack, however, still starts in high memory. so given a small utility _to_32() such as: int _to_32( long l ) { int i = l & 0xffffffff; assert( i == l ); return i; } then: char *cp = malloc( 100 ); int a = _to_32( cp ); will work reliably, as would: static char buff[ 100 ]; int a = _to_32( buff ); but: char buff[ 100 ]; int a = _to_32( buff ); will fail the assert(). anyone have a solution for this without writing custom linker scripts? or any ideas how to arrange the linker section for stack data, would appear it is being put in this section in the linker script: .lbss : { *(.dynlbss) *(.lbss .lbss.* .gnu.linkonce.lb.*) *(LARGE_COMMON) } thanks!

  Read the article

• Creating a tar file with checksums included

  - by wazoox

  Here's my problem : I need to archive to tar files a lot ( up to 60 TB) of big files (usually 30 to 40 GB each). I would like to make checksums ( md5, sha1, whatever) of these files before archiving; however not reading every file twice (once for checksumming, twice for tar'ing) is more or less a necessity to achieve a very high archiving performance (LTO-4 wants 120 MB/s sustained, and the backup window is limited). So I'd need some way to read a file, feeding a checksumming tool on one side, and building a tar to tape on the other side, something along : tar cf - files | tee tarfile.tar | md5sum - Except that I don't want the checksum of the whole archive (this sample shell code does just this) but a checksum for each individual file in the archive. I've studied GNU tar, Pax, Star options. I've looked at the source from Archive::Tar. I see no obvious way to achieve this. It looks like I'll have to hand-build something in C or similar to achieve what I need. Perl/Python/etc simply won't cut it performance-wise, and the various tar programs miss the necessary "plugin architecture". Does anyone know of any existing solution to this before I start code-churning ?

  Read the article

• problem creating jpg thumb with php

  - by Ross

  Hi, I am having problems creating a thumbnail from an uploaded image, my problem is (i) the quality (ii) the crop http://welovethedesign.com.cluster.cwcs.co.uk/phpimages/large.jpg http://welovethedesign.com.cluster.cwcs.co.uk/phpimages/thumb.jpg If you look the quality is very poor and the crop is taken from the top and is not a resize of the original image although the dimesions mean it is in proportion. The original is 1600px wide by 1100px high. Any help would be appreciated. $thumb = $targetPath."Thumbs/".$fileName; $imgsize = getimagesize($targetFile); $image = imagecreatefromjpeg($targetFile); $width = 200; //New width of image $height = 138; //This maintains proportions $src_w = $imgsize[0]; $src_h = $imgsize[1]; $thumbWidth = 200; $thumbHeight = 138; // Intended dimension of thumb // Beyond this point is simply code. $sourceImage = imagecreatefromjpeg($targetFile); $sourceWidth = imagesx($sourceImage); $sourceHeight = imagesy($sourceImage); $targetImage = imagecreate($thumbWidth,$thumbHeight); imagecopyresized($targetImage,$sourceImage,0,0,0,0,$thumbWidth,$thumbWidth,imagesx($sourceImage),imagesy($sourceImage)); //imagejpeg($targetImage, "$thumbPath/$thumbName"); imagejpeg($targetImage, $thumb); chmod($thumb, 0755);

  Read the article

• Disposing ActiveX resources owned by another thread

  - by Stefan Teitge

  I've got a problem problem with threading and disposing resources. I've got a C# Windows Forms application which runs expensive operation in a thread. This thread instantiates an ActiveX control (AxControl). This control must be disposed as it uses a high amount of memory. So I implemented a Dispose() method and even a destructor. After the thread ends the destructor is called. This is sadly called by the UI thread. So invoking activexControl.Dispose(); fails with the message "COM object that has been separated from its underlying RCW", as the object belongs to another thread. How to do this correctly or is it just a bad design I use? (I stripped the code down to the minimum including removing any safety concerns.) class Program { [STAThread] static void Main() { // do stuff here, e.g. open a form new Thread(new ThreadStart(RunStuff); // do more stuff } private void RunStuff() { DoStuff stuff = new DoStuff(); stuff.PerformStuff(); } } class DoStuff : IDisposable { private AxControl activexControl; DoStuff() { activexControl = new AxControl(); activexControl.CreateControl(); // force instance } ~DoStuff() { Dispose(); } public void Dispose() { activexControl.Dispose(); } public void PerformStuff() { // invent perpetuum mobile here, takes time } }

  Read the article

• Which are the RDBMS that minimize the server roundtrips? Which RDBMS are better (in this area) than

  - by user193655

  When the latency is high ("when pinging the server takes time") the server roundtrips make the difference. Now I don't want to focus on the roundtrips created in programming, but the roundtrips that occur "under the hood" in the DB engine, so the roundtrips that are 100% dependant on how the RDBMS is written itself. I have been told that FireBird has more roundtrips than MySQL. But this is the only information I know. I am currently supporting MS SQL but I'd like to change RDBMS (because I use Express Editions and in my scenario they are quite limiting from the performance point of view), so to make a wise choice I would like to include also this point into "my RDBMS comparison feature matrix" to understand which is the best RDBMS to choose as an alternative to MS SQL. So the bold sentence above would make me prefer MySQL to Firebird (for the roundtrips concept, not in general), but can anyone add informations? And MS SQL where is it located? Is someone able to "rank" the roundtrip performance of the main RDBMS, or at least: MS SQL, MySql, Postegresql, Firebird (I am not interested in Oracle since it is not free, and if I have to change I would change to a free RDBMS). Anyway MySql (as mentioned several times on stackoverflow) has a not clear future and a not 100% free license. So my final choice will probably dall on PostgreSQL or Firebird. Additional info: somehow you can answer my question by making a simple list like: MSSQL:3; MySQL:1; Firebird:2; Postgresql:2 (where 1 is good, 2 average, 3 bad). Of course if you can post some links where the roundtrips per RDBMSs are compared it would be great

  Read the article

< Previous Page | 520 521 522 523 524 525 526 527 528 529 530 531  | Next Page >