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  • Creating a method for wrapping a loaded image in a UIImageView

    - by eco_bach
    I have the following un my applicationDidFinishLaunching method UIImage *image2 = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"image2.jpg" ofType:nil]]; view2 = [[UIImageView alloc] initWithImage:image2]; view2.hidden = YES; [containerView addSubview:view2]; I'm simply adding an image to a view. But because I need to add 30-40 images I need to wrap the above in a function (which returns a UIImageView) and then call it from a loop. This is my first attempt at creating the function -(UIImageView)wrapImageInView:(NSString *)imagePath { UIImage *image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:imagePath ofType:nil]]; UIImageView *view = [[UIImageView alloc] initWithImage:image]; view.hidden = YES; } And then to invoke it I have the following so far, for simplicity I am only wrapping 3 images //Create an array and add elements to it NSMutableArray *anArray = [[NSMutableArray alloc] init]; [anArray addObject:@"image1.jpg"]; [anArray addObject:@"image2.jpg"]; [anArray addObject:@"image3.jpg"]; //Use a for each loop to iterate through the array for (NSString *s in anArray) { UIImageView *wrappedImgInView=[self wrapImage:s]; [containerView addSubview:wrappedImgInView]; NSLog(s); } //Release the array [anArray release]; I have 2 general questions 1-Is my approach correct?, ie following best practices, for what I am trying to do (load a multiple number of images(jpgs, pngs, etc.) and adding them to a container view) 2-For this to work properly with a large number of images, do I need to keep my array creation separate from my method invocation? Any other suggestions welcome!

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  • LINQ Joins - Performance

    - by Meiscooldude
    I am curious on how exactly LINQ (not LINQ to SQL) is performing is joins behind the scenes in relation to how Sql Server performs joins. Sql Server before executing a query, generates an Execution Plan. The Execution Plan is basically an Expression Tree on what it believes is the best way to execute the query. Each node provides information on whether to do a Sort, Scan, Select, Join, ect. On a 'Join' node in our execution plan, we can see three possible algorithms; Hash Join, Merge Join, and Nested Loops Join. Sql Server will choose which algorithm to for each Join operation based on expected number of rows in Inner and Outer tables, what type of join we are doing (some algorithms don't support all types of joins), whether we need data ordered, and probably many other factors. Join Algorithms: Nested Loop Join: Best for small inputs, can be optimized with ordered inner table. Merge Join: Best for medium to large inputs sorted inputs, or an output that needs to be ordered. Hash Join: Best for medium to large inputs, can be parallelized to scale linearly. LINQ Query: DataTable firstTable, secondTable; ... var rows = from firstRow in firstTable.AsEnumerable () join secondRow in secondTable.AsEnumerable () on firstRow.Field<object> (randomObject.Property) equals secondRow.Field<object> (randomObject.Property) select new {firstRow, secondRow}; SQL Query: SELECT * FROM firstTable fT INNER JOIN secondTable sT ON fT.Property = sT.Property Sql Server might use a Nested Loop Join if it knows there are a small number of rows from each table, a merge join if it knows one of the tables has an index, and Hash join if it knows there are a lot of rows on either table and neither has an index. Does Linq choose its algorithm for joins? or does it always use one?

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  • finding common prefix of array of strings

    - by bumperbox
    I have an array like this $sports = array( 'Softball - Counties', 'Softball - Eastern', 'Softball - North Harbour', 'Softball - South', 'Softball - Western' ); and i would like to find the longest common part of the string so in this instance, it would be 'Softball - '; I am thinking that I would follow the this process $i = 1; // loop to the length of the first string while ($i < strlen($sports[0]) { // grab the left most part up to i in length $match = substr($sports[0], 0, $i); // loop through all the values in array, and compare if they match foreach ($sports as $sport) { if ($match != substr($sport, 0, $i) { // didn't match, return the part that did match return substr($sport, 0, $i-1); } } // foreach // increase string length $i++; } // while // if you got to here, then all of them must be identical Questions is there a built in function or much simpler way of doing this ? for my 5 line array that is probably fine, but if i were to do several thousand line arrays, there would be a lot of overhead, so i would have to be move calculated with my starting values of $i, eg $i = halfway of string, if it fails, then $i/2 until it works, then increment $i by 1 until we succeed. so that we are doing the least number of comparisons to get a result If there a formula/algorithm out already out there for this kind of problem ? thanks alex

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  • asp file system object

    - by sushant
    i am using this code to access files and folders. <%@ Language=VBScript %<% option explicit dim sRoot, sDir, sParent, objFSO, objFolder, objFile, objSubFolder, sSize % <% sRoot = "D:Raghu" sDir = Request("Dir") sDir = sDir & "\" Response.Write "" & sDir & "" & vbCRLF Set objFSO = CreateObject("Scripting.FileSystemObject") on error resume next Set objFolder = objFSO.GetFolder(sRoot & sDir) if err.number < 0 then Response.Write "Could not open folder" Response.End end if on error goto 0 sParent = objFSO.GetParentFolderName(objFolder.Path) ' Remove the contents of sRoot from the front. This gives us the parent ' path relative to the root folder ' eg. if parent folder is "c:webfilessubfolder1subfolder2" then we just want "subfolder1subfolder2" sParent = mid(sParent, len(sRoot) + 1) Response.Write "" ' Give a link to the parent folder. This is just a link to this page only pssing in ' the new folder as a parameter Response.Write "Parent folder" & vbCRLF ' Now we want to loop through the subfolders in this folder For Each objSubFolder In objFolder.SubFolders ' And provide a link to them Response.Write "" & objSubFolder.Name & "" & vbCRLF Next ' Now we want to loop through the files in this folder For Each objFile In objFolder.Files if Clng(objFile.Size) < 1024 then sSize = objFile.Size & " bytes" else sSize = Clng(objFile.Size / 1024) & " KB" end if ' And provide a link to view them. This is a link to show.asp passing in the directory and the file ' as parameters Response.Write "" & objFile.Name & "" & sSize & "" & objFile.Type & "" & vbCRLF Next Response.Write "" % it works fine. but when i try to access something on shred path like: "\cvrdd0110:share" it gives error. how to access these files?

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  • Using Loops for prompts with If/Else/Esif

    - by Dante
    I started with: puts "Hello there, and what's your favorite number?" favnum = gets.to_i puts "Your favorite number is #{favnum}?" " A better favorite number is #{favnum + 1}!" puts "Now, what's your favorite number greater than 10?" favnumOverTen = gets.to_i if favnumOverTen < 10 puts "Hey! I said GREATER than 10! Try again buddy." else puts "Your favorite number great than 10 is #{favnumOverTen}?" puts "A bigger and better number over 10 is #{favnumOverTen * 10}!" puts "It's literally 10 times better!" end That worked fine, but if the user entered a number less than 10 the program ended. I want the user to be prompted to try again until they enter a number greater than 10. Am I supposed to do that with a loop? Here's what I took a swing at, but clearly it's wrong: puts "Hello there, and what's your favorite number?" favnum = gets.to_i puts "Your favorite number is #{favnum}?" " A better favorite number is #{favnum + 1}!" puts "Now, what's your favorite number greater than 10?" favnumOverTen = gets.to_i if favnumOverTen < 10 loop.do puts "Hey! I said GREATER than 10! Try again buddy." favnumOverTen = gets.to_i until favnumOverTen > 10 else puts "Your favorite number great than 10 is #{favnumOverTen}?" puts "A bigger and better number over 10 is #{favnumOverTen * 10}!" puts "It's literally 10 times better!" end

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  • Having trouble parsing XML with jQuery

    - by Jack
    Hi Guys, I'm trying to parse some XML data using jQuery, and as it stands I have extracted the 'ID' attribute of the required nodes and stored them in an array, and now I want to run a loop for each array member and eventually grab more attributes from the notes specific to each ID. The problem currently is that once I get to the 'for' loop, it isn't looping, and I think I may have written the xml path data incorrectly. It runs once and I recieve the 'alert(arrayIds.length);' only once, and it only loops the correct amount of times if I remove the subsequent xml path code. Here is my function: var arrayIds = new Array(); $(document).ready(function(){ $.ajax({ type: "GET", url: "question.xml", dataType: "xml", success: function(xml) { $(xml).find("C").each(function(){ $("#attr2").append($(this).attr('ID') + "<br />"); arrayIds.push($(this).attr('ID')); }); for (i=0; i<arrayIds.length; i++) { alert(arrayIds.length); $(xml).find("C[ID='arrayIds[i]']").(function(){ // pass values alert('test'); }); } } }); }); Any ideas?

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  • Pymedia video encoding failed

    - by user1474837
    I am using Python 2.5 with Windows XP. I am trying to make a list of pygame images into a video file using this function. I found the function on the internet and edited it. It worked at first, than it stopped working. This is what it printed out: Making video... Formating 114 Frames... starting loop making encoder Frame 1 process 1 Frame 1 process 2 Frame 1 process 2.5 This is the error: Traceback (most recent call last): File "ScreenCapture.py", line 202, in <module> makeVideoUpdated(record_files, video_file) File "ScreenCapture.py", line 151, in makeVideoUpdated d = enc.encode(da) pymedia.video.vcodec.VCodecError: Failed to encode frame( error code is 0 ) This is my code: def makeVideoUpdated(files, outFile, outCodec='mpeg1video', info1=0.1): fw = open(outFile, 'wb') if (fw == None) : print "Cannot open file " + outFile return if outCodec == 'mpeg1video' : bitrate= 2700000 else: bitrate= 9800000 start = time.time() enc = None frame = 1 print "Formating "+str(len(files))+" Frames..." print "starting loop" for img in files: if enc == None: print "making encoder" params= {'type': 0, 'gop_size': 12, 'frame_rate_base': 125, 'max_b_frames': 90, 'height': img.get_height(), 'width': img.get_width(), 'frame_rate': 90, 'deinterlace': 0, 'bitrate': bitrate, 'id': vcodec.getCodecID(outCodec) } enc = vcodec.Encoder(params) # Create VFrame print "Frame "+str(frame)+" process 1" bmpFrame= vcodec.VFrame(vcodec.formats.PIX_FMT_RGB24, img.get_size(), # Covert image to 24bit RGB (pygame.image.tostring(img, "RGB"), None, None) ) print "Frame "+str(frame)+" process 2" # Convert to YUV, then codec da = bmpFrame.convert(vcodec.formats.PIX_FMT_YUV420P) print "Frame "+str(frame)+" process 2.5" d = enc.encode(da) #THIS IS WHERE IT STOPS print "Frame "+str(frame)+" process 3" fw.write(d.data) print "Frame "+str(frame)+" process 4" frame += 1 print "savng file" fw.close() Could somebody tell me why I have this error and possibly how to fix it? The files argument is a list of pygame images, outFile is a path, outCodec is default, and info1 is not used anymore. UPDATE 1 This is the code I used to make that list of pygame images. from PIL import ImageGrab import time, pygame pygame.init() f = [] #This is the list that contains the images fps = 1 for n in range(1, 100): info = ImageGrab.grab() size = info.size mode = info.mode data = info.tostring() info = pygame.image.fromstring(data, size, mode) f.append(info) time.sleep(fps)

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  • Display two array's in the same table

    - by Naeem Ahmed
    $row = $query->fetchAll(PDO::FETCH_ASSOC); $num_rows = count($row); for ($i = 0; $i < $num_rows; $i++) { $title = htmlspecialchars($row[$i]['title']); $author =htmlspecialchars($row[$i]['author']); $school =htmlspecialchars($row[$i]['school']); $solution = $row[$i]['solution']; $notes = $row[$i]['notes']; $ad = array($title, $price, $author, $school, $contact, $content, $date); $inlcude = array($solutions, $notes); $field = 0; echo "<table border='1'>"; // foreach($inlcude as $in) This failled miserably foreach ($ad as $post) { if ($field < 3) //The first three values are placed in the first row { echo "<td>$post</td>"; } if ($field >= 3) { echo "<tr><td>$post</td><td>$in</td></tr>"; } $field++; } echo '</table>'; } I have two arrays and I would like to display them in different columns in my table. $ad displays perfectly fine but I'm having trouble displaying the contents in $inlcude in the second column. I've tried putting another foreach loop to iterate through contents of the second array but that really screws up my table by placing random values in different places on the table. Besides the foreach loop, I don't know of any other way to iterate through the array. Any suggestions would be appreciated.Thanks!

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  • Python : How to close a UDP socket while is waiting for data in recv ?

    - by alexroat
    Hello, let's consider this code in python: import socket import threading import sys import select class UDPServer: def __init__(self): self.s=None self.t=None def start(self,port=8888): if not self.s: self.s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM) self.s.bind(("",port)) self.t=threading.Thread(target=self.run) self.t.start() def stop(self): if self.s: self.s.close() self.t.join() self.t=None def run(self): while True: try: #receive data data,addr=self.s.recvfrom(1024) self.onPacket(addr,data) except: break self.s=None def onPacket(self,addr,data): print addr,data us=UDPServer() while True: sys.stdout.write("UDP server> ") cmd=sys.stdin.readline() if cmd=="start\n": print "starting server..." us.start(8888) print "done" elif cmd=="stop\n": print "stopping server..." us.stop() print "done" elif cmd=="quit\n": print "Quitting ..." us.stop() break; print "bye bye" It runs an interactive shell with which I can start and stop an UDP server. The server is implemented through a class which launches a thread in which there's a infinite loop of recv/*onPacket* callback inside a try/except block which should detect the error and the exits from the loop. What I expect is that when I type "stop" on the shell the socket is closed and an exception is raised by the recvfrom function because of the invalidation of the file descriptor. Instead, it seems that recvfrom still to block the thread waiting for data even after the close call. Why this strange behavior ? I've always used this patter to implements an UDP server in C++ and JAVA and it always worked. I've tried also with a "select" passing a list with the socket to the xread argument, in order to get an event of file descriptor disruption from select instead that from recvfrom, but select seems to be "insensible" to the close too. I need to have a unique code which maintain the same behavior on Linux and Windows with python 2.5 - 2.6. Thanks.

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  • MS Access Bulk Insert exits app

    - by Brij
    In the web service, I have to bulk insert data in MS Access database. First, There was single complex Insert-Select query,There was no error but app exited after inserting some records. I have divided the query to make it simple and using linq to remove complexity of query. now I am inserting records using for loop. there are approx 10000 records. Again, same problem. I put a breakpoint after loop, but No hit. I have used try catch, but no error found. For Each item In lstSelDel Try qry = String.Format("insert into Table(Id,link,file1,file2,pID) values ({0},""{1}"",""{2}"",""{3}"",{4})", item.WebInfoID, item.Links, item.Name, item.pName, pDateID) DAL.ExecN(qry) Catch ex As Exception Throw ex End Try Next Public Shared Function ExecN(ByVal SQL As String) As Integer Dim ret As Integer = -1 Dim nowConString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + System.AppDomain.CurrentDomain.BaseDirectory + "DataBase\\mydatabase.mdb;" Dim nowCon As System.Data.OleDb.OleDbConnection nowCon = New System.Data.OleDb.OleDbConnection(nowConString) Dim cmd As New OleDb.OleDbCommand(SQL, nowCon) nowCon.Open() ret = cmd.ExecuteNonQuery() nowCon.Close() nowCon.Dispose() cmd.Dispose() Return ret End Function After exiting app, I see w3wp.exe uses more than 50% of Memory. Any idea, What is going wrong? Is there any limitation of MS Access?

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  • iPhone crashing when presenting modal view controller

    - by Michael Waterfall
    I'm trying to display a modal view straight after another view has been presented modally (the second is a loading view that appears). - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; // Show load LoadViewController *loader = [[LoadViewController alloc] init]; [self presentModalViewController: loader animated:NO]; [loader release]; } But when I do this I get a "Program received signal: "EXC_BAD_ACCESS"." error. The stack trace is: 0 0x30b43234 in -[UIWindowController transitionViewDidComplete:fromView:toView:] 1 0x3095828e in -[UITransitionView notifyDidCompleteTransition:] 2 0x3091af0d in -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] 3 0x3091ad7c in -[UIViewAnimationState animationDidStop:finished:] 4 0x0051e331 in run_animation_callbacks 5 0x0051e109 in CA::timer_callback 6 0x302454a0 in CFRunLoopRunSpecific 7 0x30244628 in CFRunLoopRunInMode 8 0x32044c31 in GSEventRunModal 9 0x32044cf6 in GSEventRun 10 0x309021ee in UIApplicationMain 11 0x00002154 in main at main.m:14 Any ideas? I'm totally stumped! The loading view is empty so there's definitely nothing going on in there that's causing the error. Is it something to do with launching 2 views modally in the same event loop or something? Thanks, Mike Edit: Very strange... I have modified it slightly so that the loading view is shown after a tiny delay, and this works fine! So it appears to be something within the same event loop! - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; // Show load [self performSelector:@selector(doit) withObject:nil afterDelay:0.1]; } - (void)doit { [self presentModalViewController:loader animated:YES]; }

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  • [C#] Two System.Drawing methods manifest slow drawing or flickery: Solutions? or Other Options?

    - by Luke Mcneice
    Hi all, I am doing a little graphing via the System.Drawing and im having a few problems. I'm holding data in a Queue and i'm drawing(graphing) out that data onto three picture boxes this method fills the picture box then scrolls the graph across. so not to draw on top of the previous drawings (and graduly looking messier) i found 2 solutions to draw the graph. Call plot.Clear(BACKGOUNDCOLOR) before the draw loop [block commented] although this causes a flicker to appear from the time it takes to do the actual drawing loop. call plot.DrawLine(channelPen[5], j, 140, j, 0); just before each drawline [commented] although this causes the drawing to start ok then slow down very quickly to a crawl as if a wait command had been placed before the draw command. Here is the Code for reference: /*plotx.Clear(BACKGOUNDCOLOR) ploty.Clear(BACKGOUNDCOLOR) plotz.Clear(BACKGOUNDCOLOR)*/ for (int j = 1; j < 599; j++) { if (j > RealTimeBuffer.Count - 1) break; QueueEntity past = RealTimeBuffer.ElementAt(j - 1); QueueEntity current = RealTimeBuffer.ElementAt(j); if (j == 1) { //plotx.DrawLine(channelPen[5], 0, 140, 0, 0); //ploty.DrawLine(channelPen[5], 0, 140, 0, 0); //plotz.DrawLine(channelPen[5], 0, 140, 0, 0); } //plotx.DrawLine(channelPen[5], j, 140, j, 0); plotx.DrawLine(channelPen[0], j - 1, (((past.accdata.X - 0x7FFF) / 256) + 64), j, (((current.accdata.X - 0x7FFF) / 256) + 64)); //ploty.DrawLine(channelPen[5], j, 140, j, 0); ploty.DrawLine(channelPen[1], j - 1, (((past.accdata.Y - 0x7FFF) / 256) + 64), j, (((current.accdata.Y - 0x7FFF) / 256) + 64)); //plotz.DrawLine(markerPen, j, 140, j, 0); plotz.DrawLine(channelPen[2], j - 1, (((past.accdata.Z - 0x7FFF) / 256) + 94), j, (((current.accdata.Z - 0x7FFF) / 256) + 94)); } Is there any tricks to avoid these overheads? If not would there be any other/better solutions?

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  • Real Time Progress Indicator

    - by jignesh
    I am trying to get the real time progress indicator. In the code snippet below,i am trying to set the width of DIV on the basis of the Number of Items retrieve from the Web Service Call Back Function. for (i = 0; i < data.length; i++) { table += '<tr>'; table += '<td>' + data[i].ItemId + '</td>'; table += '<td></td>'; table += '<td>' + data[i].Name + '</td>'; table += '<td>' + data[i].Unit + '</td>'; table += '<td><input type=text value=' + data[i].Quantity + '></td>'; table += '<td>' + data[i].Brands + '</td>'; table += '<td><img border=0 src=../images/Delete_icon.gif></td>'; table += '</tr>'; $('#divProgressIndicator').width((100 * (i / data.length)) + '%'); } As shown in the code above,after the for loop is executed i only see the divProgressIndicator filled with the background color and I am not able to see the progress. Can I achieve this in a for loop or i need to use some thing else. Regards

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  • How do you use stl's functions like for_each?

    - by thomas-gies
    I started using stl containers because they came in very handy when I needed functionality of a list, set and map and had nothing else available in my programming environment. I did not care much about the ideas behind it. STL documentations were only interesting up to the point where it came to functions, etc. Then I skipped reading and just used the containers. But yesterday, still being relaxed from my holidays, I just gave it a try and wanted to go a bit more the stl way. So I used the transform function (can I have a little bit of applause for me, thank you). From an academic point of view it really looked interesting and it worked. But the thing that boroughs me is that if you intensify the use of those functions, you need 10ks of helper classes for mostly everything you want to do in your code. The hole logic of the program is sliced in tiny pieces. This slicing is not the result of god coding habits. It's just a technical need. Something, that makes my life probably harder not easier. And I learned the hard way, that you should always choose the simplest approach that solves the problem at hand. And I can't see what, for example, the for_each function is doing for me that justifies the use of a helper class over several simple lines of code that sit inside a normal loop so that everybody can see what is going on. I would like to know, what you are thinking about my concerns? Did you see it like I do when you started working this way and have changed your mind when you got used to it? Are there benefits that I overlooked? Or do you just ignore this stuff as I did (and will go an doing it, probably). Thanks. PS: I know that there is a real for_each loop in boost. But I ignore it here since it is just a convenient way for my usual loops with iterators I guess.

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  • How do I return the value of the owner and id attributes respectively from an XML result set using P

    - by pharma_joe
    I am using PHP to iterate over the following result set, the aim is to build a hyperlink for each result using a foreach loop. I have stored the XML result in $images, and have constructed this loop: foreach ($images as $image) { //Build link to each photo returned //base URL $flickrPhotoUrl = 'http://www.flickr.com/photos/'; //Append user ID $flickrPhotoUrl .= ""; echo $flickrPhotoUrl; } Here is a sample result from Flickr: <photos page="1" pages="10982" perpage="10" total="109813"> <photo id="4616840471" owner="47823583@N03" secret="1b83173bc0" server="4013" farm="5" title="Strawberry Bears" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4616612597" owner="12658756@N08" secret="f626214382" server="4059" farm="5" title="Yarn Chef Minestrone - Grickle Grass" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4616469567" owner="26284268@N00" secret="6911a66838" server="4022" farm="5" title="P5130121.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4617076736" owner="26284268@N00" secret="8b990acba4" server="4047" farm="5" title="P5130106.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4616470013" owner="26284268@N00" secret="44600b3836" server="4036" farm="5" title="P5130125.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4616466147" owner="26284268@N00" secret="554eab8667" server="4052" farm="5" title="P5130116.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4617082398" owner="26284268@N00" secret="4a2b663442" server="3350" farm="4" title="P5130118.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4617078272" owner="26284268@N00" secret="357737017b" server="4013" farm="5" title="P5130109.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4617081446" owner="26284268@N00" secret="1f87726497" server="4048" farm="5" title="P5130117.JPG" ispublic="1" isfriend="0" isfamily="0"></photo> <photo id="4617077676" owner="26284268@N00" secret="77ca9f754a" server="3330" farm="4" title="P5130108.JPG" ispublic="1" isfriend="0" isfamily="0"></photo>

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  • How to check if a number is a power of 2

    - by configurator
    Today I needed a simple algorithm for checking if a number is a power of 2. The algorithm needs to be: Simple Correct for any ulong value. I came up with this simple algorithm: private bool IsPowerOfTwo(ulong number) { if (number == 0) return false; for (ulong power = 1; power > 0; power = power << 1) { // this for loop used shifting for powers of 2, meaning // that the value will become 0 after the last shift // (from binary 1000...0000 to 0000...0000) then, the for // loop will break out if (power == number) return true; if (power > number) return false; } return false; } But then I thought, how about checking if log2x is an exactly round number? But when I checked for 2^63+1, Math.Log returned exactly 63 because of rounding. So I checked if 2 to the power 63 is equal to the original number - and it is, because the calculation is done in doubles and not in exact numbers: private bool IsPowerOfTwo_2(ulong number) { double log = Math.Log(number, 2); double pow = Math.Pow(2, Math.Round(log)); return pow == number; } This returned true for the given wrong value: 9223372036854775809. Does anyone have any suggestion for a better algorithm?

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  • java number exceeds long.max_value - how to detect?

    - by jurchiks
    I'm having problems detecting if a sum/multiplication of two numbers exceeds the maximum value of a long integer. Example code: long a = 2 * Long.MAX_VALUE; System.out.println("long.max * smth > long.max... or is it? a=" + a); This gives me -2, while I would expect it to throw a NumberFormatException... Is there a simple way of making this work? Because I have some code that does multiplications in nested IF blocks or additions in a loop and I would hate to add more IFs to each IF or inside the loop. Edit: oh well, it seems that this answer from another question is the most appropriate for what I need: http://stackoverflow.com/a/9057367/540394 I don't want to do boxing/unboxing as it adds unnecassary overhead, and this way is very short, which is a huge plus to me. I'll just write two short functions to do these checks and return the min or max long. Edit2: here's the function for limiting a long to its min/max value according to the answer I linked to above: /** * @param a : one of the two numbers added/multiplied * @param b : the other of the two numbers * @param c : the result of the addition/multiplication * @return the minimum or maximum value of a long integer if addition/multiplication of a and b is less than Long.MIN_VALUE or more than Long.MAX_VALUE */ public static long limitLong(long a, long b, long c) { return (((a > 0) && (b > 0) && (c <= 0)) ? Long.MAX_VALUE : (((a < 0) && (b < 0) && (c >= 0)) ? Long.MIN_VALUE : c)); } Tell me if you think this is wrong.

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  • How can I do something when a runloop event is done processing?

    - by quixoto
    I have some processing in my Cocoa app that sometimes ends up calling through a hierarchy of data to do a bunch of work as the result of an event. Each small piece creates and destroys some resources. I don't want those resources around most of the time, but I would like to find a smart way of creating them before all the work and killing them at the end. Short of making those buffers etc available globally from the "parent" or elsewhere, is there a way to know locally in some code when an event loop run has ended? Then I could create them if they're not there, and keep them until the run loop ends, reusing them for any subsequent calls before that time. EDIT: I'm not looking for suggestions on how to restructure my code, which I may do anyways. This issue just brought up the question for me of how to know when the runloop is done. If I were writing in, I dunno, Javascript, I'd use a setTimeout with zero to accomplish end-event cleanup. I suppose an NSTimer with an interval of zero might accomplish this too, but wondering if there's something cleaner. Thanks.

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  • Dynamic evaluation of a table column within an insert before trigger

    - by Tim Garver
    HI All, I have 3 tables, main, types and linked. main has an id column and 32 type columns. types has id, type linked has id, main_id, type_id I want to create an insert before trigger on the main table. It needs to compare its 32 type columns to the values in the types table if the main table column has an 'X' for its value and insert the main_id and types_id into the linked table. i have done a lot of searching, and it looks like a prepared statement would be the way to go, but i wanted to ask the experts. The issue, is i dont want to write 32 IF statements, and even if i did, i need to query the types table to get the ID for that type, seems like a huge waist of resources. Ideally i want to do this inside of my trigger: BEGIN DECLARE @types results_set -- (not sure if this is a valid type); -- (iam sure my loop syntax is all wrong here)... SET @types = (select * from types) for i=0;i<types.records;i++ { IF NEW.[i.type] = 'X' THEN insert into linked (main_id,type_id) values (new.ID, i.id); END IF; } END; Anyway, This is what i was hoping to do, maybe there is a way to dynamically set the field name inside of a results loop, but i cant find a good example of this. Thanks in advance Tim

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  • Findbugs and comparing

    - by Rob Goodwin
    I recently started using the findbugs static analysis tool in a java build I was doing. The first report came back with loads of High Priority warnings. Being the obsessive type of person, I was ready to go knock them all out. However, I must be missing something. I get most of the warnings when comparing things. Such as the following code: public void setSpacesPerLevel(int value) { if( value >= 0) { ... produces a high priority warning at the if statement that reads. File: Indenter.java, Line: 60, Type: BIT_AND_ZZ, Priority: High, Category: CORRECTNESS Check to see if ((...) & 0) == 0 in sample.Indenter.setSpacesPerLevel(int) I am comparing an int to an int, seems like a common thing. I get quite a few of that type of error with similar simple comparisons. I have alot of other high priority warnings on what appears to be simple code blocks. Am I missing something here? I realize that static analysis can produce false positives, but the errors I am seeing seem too trivial of a case to be a false positive. This one has me scratching my head as well. for(int spaces = 0;spaces < spacesPerLevel;spaces++){... Which gives the following findbugs warning: File: Indenter.java, Line: 160, Type: IL_INFINITE_LOOP, Priority: High, Category: CORRECTNESS There is an apparent infinite loop in sample.Indenter.indent() This loop doesn't seem to have a way to terminate (other than by perhaps throwing an exception). Any ideas? So basically I have a handful of files and 50-60 high priority warnings similar to the ones above. I am using findbugs 1.3.9 and calling it from the findbugs ant task

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  • one key multiple values from different sources c#

    - by user2964034
    I am trying to make a c# program that will compare two files for me, and tell me the differences of specific parts. I have been able to get the parts I need into variables while looping through, but I now want to add these to a key with 3 values per file, so a key with 6 values overall which I will then compare to eachother later on. But I can only add 3 values at a time using the loop I have, so I need to be able to add the last 3 values to the key without overwriting the first 3. example of data from file: [\Advanced\Rules\Correlation Rules\Suspect_portscan\]; CheckDescription =S Detect Port scans; Enabled =B 0; Priority =L 3; I have managed to get what I need into variables so I have: string SigName would be "Suspect_portscan" Int Enabled, Priority, Blocking as 0 3 and null respectivly. I then want to make a dictionary type thing, with a key which would be the SigName and the first 3 values as enabled, priority, blocking. Then when looping through the second file, I want to add the 2nd files settings for the enabled, priority, blocking for the same SigName (so to the key) in the last 3 value slots. I will then compare this against itself, like 'if signame(0) != signame(3)' so if file 1 enabled is not the same as file two enabled make a note and tell me. But the problem I have is not being able to get the data into a dictionary or lookup, I'm completely stumped. It seems like I should use a dictionary with a list for the values but I cant get it working on the second loop through. Thanks.

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  • Clarification on Threads and Run Loops In Cocoa

    - by dubbeat
    I'm trying to learn about threading and I'm thoroughly confused. I'm sure all the answers are there in the apple docs but I just found it really hard to breakdown and digest. Maybe somebody could clear a thing or 2 up for me. 1)performSelectorOnMainThread Does the above simply register an event in the main run loop or is it somehow a new thread even though the method says "mainThread"? If the purpose of threads is to relieve processing on the main thread how does this help? 2) RunLoops Is it true that if I want to create a completely seperate thread I use "detachNewThreadSelector"? Does calling start on this initiate a default run loop for the thread that has been created? If so where do run loops come into it? 3) And Finally , I've seen examples using NSOperationQueue. Is it true to say that If you use performSelectorOnMainThread the threads are in a queue anyway so NSOperation is not needed? 4) Should I forget about all of this and just use the Grand Central Dispatch instead?

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  • How to copy a variable in JavaScript?

    - by Michael Stum
    I have this JavaScript code: for (var idx in data) { var row = $("<tr></tr>"); row.click(function() { alert(idx); }); table.append(row); } So I'm looking through an array, dynamically creating rows (the part where I create the cells is omitted as it's not important). Important is that I create a new function which encloses the idx variable. However, idx is only a reference, so at the end of the loop, all rows have the same function and all alert the same value. One way I solve this at the moment is by doing this: function GetRowClickFunction(idx){ return function() { alert(idx); } } and in the calling code I call row.click(GetRowClickFunction(idx)); This works, but is somewhat ugly. I wonder if there is a better way to just copy the current value of idx inside the loop? While the problem itself is not jQuery specific (it's related to JavaScript closures/scope), I use jQuery and hence a jQuery-only solution is okay if it works.

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  • Terminal-based snake game: input thread manipulates output

    - by enlightened
    I'm writing a snake game for the terminal, i.e. output via print. The following works just fine: while status[snake_monad] do print to_string draw canvas, compose_all([ frame, specs, snake_to_hash(snake[snake_monad]) ]) turn! snake_monad, get_dir move! snake_monad, specs sleep 0.25 end But I don't want the turn!ing to block, of course. So I put it into a new Thread and let it loop: Thread.new do loop do turn! snake_monad, get_dir end end while status[snake_monad] do ... # no turn! here ... end Which also works logically (the snake is turning), but the output is somehow interspersed with newlines. As soon as I kill the input thread (^C) it looks normal again. So why and how does the thread have any effect on my output? And how do I work around this issue? (I don't know much about threads, even less about them in ruby. Input and output concurrently on the same terminal make the matter worse, I guess...) Also (not really important): Wanting my program as pure as possible, would it be somewhat easily possible to get the input non-blockingly while passing everything around? Thank you!

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  • How to properly handle signals when using the worker thread pattern?

    - by ipartola
    I have a simple server that looks something like this: void *run_thread(void *arg) { // Communicate via a blocking socket } int main() { // Initialization happens here... // Main event loop while (1) { new_client = accept(socket, ...); pthread_create(&thread, NULL, &run_thread, *thread_data*); pthread_detach(thread); } // Do cleanup stuff: close(socket); // Wait for existing threads to finish exit(0); ) Thus when a SIGINT or SIGTERM is received I need to break out of the main event loop to get to the clean up code. Moreover most likely the master thread is waiting on the accept() call so it's not able to check some other variable to see if it should break;. Most of the advice I found was along the lines of this: http://devcry.blogspot.com/2009/05/pthreads-and-unix-signals.html (creating a special signal handling thread to catch all the signals and do processing on those). However, it's the processing portion that I can't really wrap my head around: how can I possibly tell the main thread to return from the accept() call and check on an external variable to see if it should break;?

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