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  • how I can convert the string output into data.frame

    - by user2968058
    i have a data set called SIZEDIST$AVG.µm., and i have fitted this data with a weibull curve. now i have generated the quantiles by using the quantile function and now i want to access the output of this function generated at the interval of p=0.01. fwbl<-fitdist(SIZEDIST$AVG.µm., "weibull",start=list(shape=0.8,scale=1)) fwbl quantwbl<-quantile(fwbl,probs=seq(.1,.99,.01)) quantwbl str(quantwbl) using str(quantwbl) i can visualize the output but i cant convert them into data.frame

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  • Are doubles faster than floats in c#?

    - by Trap
    I'm writing an application which reads large arrays of floats and performs some simple operations with them. I'm using floats because I thought it'd be faster than doubles, but after doing some research I've found that there's some confusion about this topic. Can anyone elaborate on this? Thanks.

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  • Get file size of BufferedImage before writing the data

    - by David
    I'm working on a Java program that needs to send an image (preferably in PNG format, though I could perhaps use another format if necessary) over the network. The logical way to do this is, of course, to first send the length of the PNG image data, then the data itself. Problem: I don't see any method in ImageIO or anywhere else that will give me the length of the image data. Does this exist somewhere in the Java 1.6 standard library? I know I could just write it to a ByteArrayOutputStream and get the length of the resulting array, but before resorting that I wanted to make sure I'm not missing something built in. And besides, that makes an extra copy of the image data, which I'd rather not do if it's not necessary.

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  • How To Securly Store Data In MySQL Using AES_ENCRYPT

    - by Justin
    We are storing sensitive data in MySQL, and I want to use AES_ENCRYPT(data, 'my-secret-key-here') which works great. My biggest question is how do I secure the key? Previously I just wast storing the key in a web PHP file, so something like: define("ENCRYPTION_KEY", 'my-secret-key-here'); This really doesn't work though, as our MySQL server and web server are the same physical machine, so if somebody gains access to the server, they can get both the encrypted data stored in MySQL and the key. Any ideas? I am thinking I need to move the key to a separate server, and read it in remotely. Or, what about generating the encryption key dynamically for each piece of data. For example taking the customer_id and running md5 on it, and then using that as the key.

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  • Strange profiler behavior: same functions, different performances

    - by arthurprs
    I was learning to use gprof and then i got weird results for this code: int one(int a, int b) { return a / (b + 1); } int two(int a, int b) { return a / (b + 1); } int main() { for (int i = 1; i < 30000000; i++) { two(i, i * 2); one(i, i * 2); } return 0; } and this is the profiler output % cumulative self self total time seconds seconds calls ns/call ns/call name 48.39 0.90 0.90 29999999 30.00 30.00 one(int, int) 40.86 1.66 0.76 29999999 25.33 25.33 two(int, int) 10.75 1.86 0.20 main If i call one then two the result is the inverse, two takes more time than one both are the same functions, but the first calls always take less time then the second Why is that? Note: The assembly code is exactly the same and code is being compiled with no optimizations

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  • How to store data which contains quotes in MySQL

    - by Nitz
    In one of my forms I use the rich text editor from Yahoo!. Now i want to store the data from that textarea in a MySQL database. The user can enter anything in that textarea, e.g. many double or single quotes. How can I store that data? Normally we store by adding that data in one variable and then put that in sql, but the quotes cause problems.

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  • 2k rows update is very slow in MySQL

    - by sergeik
    Hi all, I have 2 tables: 1. news (450k rows) 2. news_tags (3m rows) There are some triggers on news table update which updating listings. This SQL executes too long... UPDATE news SET news_category = some_number WHERE news_id IN (SELECT news_id FROM news_tags WHERE tag_id = some_number); #about 3k rows How can I make it faster? Thanks in advance, S.

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  • What GC parameters is a JVM running with?

    - by skaffman
    I'm still investigating issues I have with GC tuning (see prior question), which involves lots of reading and experimentation. Sun Java5+ JVMs attempt to automatically select the optimal GC strategy and parameters based on their environment, which is great, but I can't figure out how to query the running JVM to find out what those parameters are. Ideally, I'd like to see what values of the various GC-related -XX options are being used, as selected automatically by the VM. If I had that, I could have a baseline to begin tweaking. Anyone know to recover these values from a running VM?

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  • Assigning data to an <li> element?

    - by user246114
    Hi, I am generating some list items as a result of a search, and I want to attach some data to each list element from the search (possibly a bad idea to merge ui and data), but now curious about it. I am doing this: var element = $("<li>Hello</li>); element.mydata = "foo"; element.appendTo("#panelParent"); so I'm just assigning my stuff to element.mydata. My click handler reports that no such data exists for the element when clicked: $('#panelParent').delegate('li', 'click', function() { // this.mydata is undefined. }); where did it go to? I could keep the data external to the a list item element, was wondering if there's a convenient way like this to just keep it bound though? Thanks

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  • Optimizing Code

    - by Claudiu
    You are given a heap of code in your favorite language which combines to form a rather complicated application. It runs rather slowly, and your boss has asked you to optimize it. What are the steps you follow to most efficiently optimize the code? What strategies have you found to be unsuccessful when optimizing code? Re-writes: At what point do you decide to stop optimizing and say "This is as fast as it'll get without a complete re-write." In what cases would you advocate a simple complete re-write anyway? How would you go about designing it?

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  • How to optimize this simple function which translates input bits into words?

    - by psihodelia
    I have written a function which reads an input buffer of bytes and produces an output buffer of words where every word can be either 0x0081 for each ON bit of the input buffer or 0x007F for each OFF bit. The length of the input buffer is given. Both arrays have enough physical place. I also have about 2Kbyte free RAM which I can use for lookup tables or so. Now, I found that this function is my bottleneck in a real time application. It will be called very frequently. Can you please suggest a way how to optimize this function? I see one possibility could be to use only one buffer and do in-place substitution. void inline BitsToWords(int8 *pc_BufIn, int16 *pw_BufOut, int32 BufInLen) { int32 i,j,z=0; for(i=0; i<BufInLen; i++) { for(j=0; j<8; j++, z++) { pw_BufOut[z] = ( ((pc_BufIn[i] >> (7-j))&0x01) == 1? 0x0081: 0x007f ); } } } Please do not offer any compiler specific or CPU/Hardware specific optimization, because it is a multi-platform project.

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  • Which .NET data provider?

    - by worlds-apart89
    I am new to database programming, so I'd like help getting on the right track. I have read that there are Microsoft-defined and third-party data providers for data access. MSDN has information on data providers for SQL Server, OLE DB, ODBC, Oracle, as well as the EntityClient provider (Entity Framework). Which data provider is today's hottest, most-widely used model? Which one is the future? Also, I have seen Linq to SQL tutorials, but what category does L2S fall into?

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  • draw graph in android with dynamically data

    - by Tikam
    In my project i want to draw a graph with dynamically updated data, and data is came from remote device and i update it from my locally sqlite data base. I have to draw a graph dynamically with having two paremeter as horizontally hours of day from {Mid night, 1, 2, ...., 11, Noon, 1 , 11, Mid Night} and vertically parameter as {One , two, Three, Four}. At particular hour i get data value from my sqlite and want to draw it on graph, and any particular hour have different value like "One", "two" etc. and i want to draw graph with hour help. Thanks in advance

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  • Why is Dictionary.First() so slow?

    - by Rotsor
    Not a real question because I already found out the answer, but still interesting thing. I always thought that hash table is the fastest associative container if you hash properly. However, the following code is terribly slow. It executes only about 1 million iterations and takes more than 2 minutes of time on a Core 2 CPU. The code does the following: it maintains the collection todo of items it needs to process. At each iteration it takes an item from this collection (doesn't matter which item), deletes it, processes it if it wasn't processed (possibly adding more items to process), and repeats this until there are no items to process. The culprit seems to be the Dictionary.Keys.First() operation. The question is why is it slow? Stopwatch watch = new Stopwatch(); watch.Start(); HashSet<int> processed = new HashSet<int>(); Dictionary<int, int> todo = new Dictionary<int, int>(); todo.Add(1, 1); int iterations = 0; int limit = 500000; while (todo.Count > 0) { iterations++; var key = todo.Keys.First(); var value = todo[key]; todo.Remove(key); if (!processed.Contains(key)) { processed.Add(key); // process item here if (key < limit) { todo[key + 13] = value + 1; todo[key + 7] = value + 1; } // doesn't matter much how } } Console.WriteLine("Iterations: {0}; Time: {1}.", iterations, watch.Elapsed); This results in: Iterations: 923007; Time: 00:02:09.8414388. Simply changing Dictionary to SortedDictionary yields: Iterations: 499976; Time: 00:00:00.4451514. 300 times faster while having only 2 times less iterations. The same happens in java. Used HashMap instead of Dictionary and keySet().iterator().next() instead of Keys.First().

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  • Need help with transferring data between MySQL db's using PHP

    - by JM4
    In one of the sites I manage, the client has decided to take on ACH/Bank Account administration where it was previously outsourced. As a result, the information submitted in our online form which used to simply store in a single database for processing now must sit in 'limbo' until the funds used for payment have been verified. My original plan is as follows: At the end of an enrollment, all form data is collected and stored in a single MySQL database. Our internal administrator will receive an email notification reminding him enrollments have taken place. He will process the ACH information collected and wait the 3-4 business days needed for payment to clear. Once the payment information has been returned as Good (haven't considered what I will do with the 'bad' yet), the administrator can log into a secure portal which allows him to click a button to 'process' the full information once compared and verified. the process is simplified as: Enrollment complete: data stored in DB 'A' Funds verified and link clicked: data from 'A' is copied to DB 'B' and 'A' is deleted. I have run similar processes with CSV output before and simply used //transfers old data to archive $transfer = mysql_query('INSERT INTO '.$archive.' SELECT * FROM '.$table) or die(mysql_error()); //empties existing table $query = mysql_query('TRUNCATE TABLE '.$table) or die(mysql_error()); but in those cases, ALL data returned was copied and deleted. I only want to copy and delete a single record. Any idea how to accomplish this?

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  • require_once at the beginning or when really needed?

    - by takeshin
    Where should I put require_once statements, and why? Always on the beginning of a file, before the class, In the actual method when the file is really needed It depends ? Most frameworks put includes at the beginning and do not care if the file is really needed. Using autoloader is the other case here.

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  • Why is my regex so much slower compiled than interpreted ?

    - by miket2e
    I have a large and complex C# regex that runs OK when interpreted, but is a bit slow. I'm trying to speed this up by setting RegexOptions.Compiled, and this seems to take about 30 seconds for the first time and instantly after that. I'm trying to negate this by compiling the regex to an assembly first, so my app can be as fast as possible. My problem is when the compiling delay takes place: Regex myComplexRegex = new Regex(regexText, RegexOptions.Compiled); MatchCollection matches = myComplexRegex.Matches(searchText); foreach (Match match in matches) // <--- when the one-time long delay kicks in { } This is making compiling to an assembly basically useless, as I still get the delay on the first foreach call. What I want is for all the compiling delay to be done in advance when I compile to the assembly, not when the user runs the app. Where am I going wrong ? (The code I'm using to compile to an assembly is similar to http://www.dijksterhuis.org/regular-expressions-advanced/ , if that's relevant ).

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  • Binding data asp.net web forms C#

    - by user2372566
    I am developing a project in asp.net web forms. I have a little problem. Whent the page load, I load some data from the dabase and present it on the page. On the same page I have form where I can input some textobox and with the click on the button make update on the same data in the database whis is at the first time loaded on the same page? The date is update, I can see it in SQL SERVER, but on the web page not. Its still the old data presents. After I close my application and run it again, then the new data appears on the page.

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  • How to transfer data from MYsql server to iphone

    - by creator7
    Hi All, I created a webservice in RDB with .Net.I able to transfer data from iphone to mysql and it returns the data. But i need to transfer data from RDB to iphone whenever i need (i am strucked by the ip address of iphone which one is dynamic to connect the device from a RDB) Please tell me how i will do it otherwise tell is any other way. Thanks in Advance

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  • How to speed up drawing of scaled image? Audio playback chokes during window resize.

    - by Paperflyer
    I am writing an audio player for OSX. One view is a custom view that displays a waveform. The waveform is stored as a instance variable of type NSImage with an NSBitmapImageRep. The view also displays a progress indicator (a thick red line). Therefore, it is updated/redrawn every 30 milliseconds. Since it takes a rather long time to recalculate the image, I do that in a background thread after every window resize and update the displayed image once the new image is ready. In the meantime, the original image is scaled to fit the view like this: // The drawing rectangle is slightly smaller than the view, defined by // the two margins. NSRect drawingRect; drawingRect.origin = NSMakePoint(sideEdgeMarginWidth, topEdgeMarginHeight); drawingRect.size = NSMakeSize([self bounds].size.width-2*sideEdgeMarginWidth, [self bounds].size.height-2*topEdgeMarginHeight); [waveform drawInRect:drawingRect fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1]; The view makes up the biggest part of the window. During live resize, audio starts choking. Selecting the "big" graphic card on my Macbook Pro makes it less bad, but not by much. CPU utilization is somewhere around 20-40% during live resizes. Instruments suggests that rescaling/redrawing of the image is the problem. Once I stop resizing the window, CPU utilization goes down and audio stops glitching. I already tried to disable image interpolation to speed up the drawing like this: [[NSGraphicsContext currentContext] setImageInterpolation:NSImageInterpolationNone]; That helps, but audio still chokes during live resizes. Do you have an idea how to improve this? The main thing is to prevent the audio from choking.

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