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  • Crystal Reports Programmatic Image Resizing... Scale?

    - by C. Griffin
    I'm working with a Crystal Reports object in Visual Studio 2008 (C#). The report is building fine and the data is binding correctly. However, when I try to resize an IBlobFieldObject from within the source, the scale is getting skewed. Two notes about this scenario. Source image is 1024x768, my max width and height are 720x576. My math should be correct that my new image size will be 720x540 (to fit within the max width and height guidelines). The ratio is wrong when I do this though: img = Image.FromFile(path); newWidth = img.Size.Width; newHeight = img.Size.Height; if ((img.Size.Width > 720) || (img.Size.Height > 576)) { double ratio = Convert.ToDouble(img.Size.Width) / Convert.ToDouble(img.Size.Height); if (ratio > 1.25) // Adjust width to 720, height will fall within range { newWidth = 720; newHeight = Convert.ToInt32(Convert.ToDouble(img.Size.Height) * 720.0 / Convert.ToDouble(img.Size.Width)); } else // Adjust height to 576, width will fall within range { newHeight = 576; newWidth = Convert.ToInt32(Convert.ToDouble(img.Size.Width) * 576.0 / Convert.ToDouble(img.Size.Height)); } imgRpt.Section3.ReportObjects["image"].Height = newHeight; imgRpt.Section3.ReportObjects["image"].Width = newWidth; } I've stepped through the code to make sure that the values are correct from the math, and I've even saved the image file out to make sure that the aspect ratio is correct (it was). No matter what I try though, the image is squashed--almost as if the Scale values are off in the Crystal Reports designer (they're not). Thanks in advance for any help!

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  • Transforming coordinates from an image control to the image source in WPF

    - by Gabriel
    I'm trying to learn WPF, so here's a simple question, I hope: I have a window that contains an Image element bound to a separate data object with user-configurable Stretch property <Image Name="imageCtrl" Source="{Binding MyImage}" Stretch="{Binding ImageStretch}" /> When the user moves the mouse over the image, I would like to determine the coordinates of the mouse with respect to the original image (before stretching/cropping that occurs when it is displayed in the control), and then do something with those coordinates (update the image). I know I can add an event-handler to the MouseMove event over the Image control, but I'm not sure how best to transform the coordinates: void imageCtrl_MouseMove(object sender, MouseEventArgs e) { Point locationInControl = e.GetPosition(imageCtrl); Point locationInImage = ??? updateImage(locationInImage); } Now I know I could compare the size of Source to the ActualSize of the control, and then switch on imageCtrl.Stretch to compute the scalars and offsets on X and Y, and do the transform myself. But WPF has all the information already, and this seems like functionality that might be built-in to the WPF libraries somewhere. So I'm wondering: is there a short and sweet solution? Or do I need to write this myself? EDIT I'm appending my current, not-so-short-and-sweet solution. Its not that bad, but I'd be somewhat suprised if WPF didn't provide this functionality automatically: Point ImgControlCoordsToPixelCoords(Point locInCtrl, double imgCtrlActualWidth, double imgCtrlActualHeight) { if (ImageStretch == Stretch.None) return locInCtrl; Size renderSize = new Size(imgCtrlActualWidth, imgCtrlActualHeight); Size sourceSize = bitmap.Size; double xZoom = renderSize.Width / sourceSize.Width; double yZoom = renderSize.Height / sourceSize.Height; if (ImageStretch == Stretch.Fill) return new Point(locInCtrl.X / xZoom, locInCtrl.Y / yZoom); double zoom; if (ImageStretch == Stretch.Uniform) zoom = Math.Min(xZoom, yZoom); else // (imageCtrl.Stretch == Stretch.UniformToFill) zoom = Math.Max(xZoom, yZoom); return new Point(locInCtrl.X / zoom, locInCtrl.Y / zoom); }

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  • "Permission denied to access property 'href' from a non-chrome context" in JavaScript and OpenLayers

    - by Mark Iliffe
    This is really two questions one leading into the other. Firstly what does 'Permission denied to access property 'href' from a non-chrome context' actually mean? Secondly I am using overlays in OpenLayers and wish to change the opacity of said layers, this is where this error is being thrown the code of which is here... <input id='opacity' value="1.0" onChange="changeOpacity()"> Of which changeOpacity() is the following function... function changeOpacity() { var newOpacity = parseFloat(OpenLayers.Util.getElement('opacity').value); newOpacity = Math.min(1.0, Math.max(0.1, newOpacity)); OpenLayers.Util.getElement('opacity').value = newOpacity; for (var i=0; i<images.length; i++) { layers[images[i]].setOpacity(newOpacity); } } which throws the error at "var href = originalElement.href;" here... function mD(e) { //what is originalElement/srcElement/originalTarget? var originalElement = e.srcElement || e.originalTarget; var href = originalElement.href; if (originalElement.nodeName == "A" && href.match("http://www.openstreetmap.org/browse/")) { href = href.replace('http://www.openstreetmap.org/browse/','http://www.openstreetmap.org/api/0.6/'); if (gml) { map.removeLayer(gml); } //$("status").innerHTML = 'loading'; } gml = new OpenLayers.Layer.GML("OSM", href, {format: OpenLayers.Format.OSM}); map.addLayer(gml); gml.preFeatureInsert = style_osm_feature; var sf = new OpenLayers.Control.SelectFeature(gml, {'onSelect': on_feature_hover}); map.addControl(sf); sf.activate(); return false; } } Any help/ideas is great appreciated! I am using firefox 3.5.9 and firebug 1.5.4

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  • Java random values and duplicates

    - by f-Prime
    I have an array (cards) of 52 cards (13x4), and another array (cardsOut) of 25 cards (5x5). I want to copy elements from the 52 cards into the 25 card array by random. Also, I dont want any duplicates in the 5x5 array. So here's what I have: double row=Math.random() *13; double column=Math.random() *4; boolean[][] duplicates=new boolean[13][4]; pokerGame[][] cardsOut = new pokerGame[5][5]; for (int i=0;i<5;i++) for (int j=0;j<5;j++){ if(duplicates[(int)row][(int)column]==false){ cardsOut[i][j]=cards[(int)row][(int)column]; duplicates[(int)row][(int)column]=true; } } 2 problems in this code. First, the random values for row and column are only generated once, so the same value is copied into the 5x5 array every time. Since the same values are being copied every time, I'm not sure if my duplicate checker is very effective, or if it works at all. How do I fix this?

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  • Saturated addition of two signed Java 'long' values

    - by finnw
    How can one add two long values (call them x and y) in Java so that if the result overflows then it is clamped to the range Long.MIN_VALUE..Long.MAX_VALUE? For adding ints one can perform the arithmetic in long precision and cast the result back to an int, e.g.: int saturatedAdd(int x, int y) { long sum = (long) x + (long) y; long clampedSum = Math.max((long) Integer.MIN_VALUE, Math.min(sum, (long) Integer.MAX_VALUE)); return (int) clampedSum; } or import com.google.common.primitives.Ints; int saturatedAdd(int x, int y) { long sum = (long) x + (long) y; return Ints.saturatedCast(sum); } but in the case of long there is no larger primitive type that can hold the intermediate (unclamped) sum. Since this is Java, I cannot use inline assembly (in particular SSE's saturated add instructions.) It can be implemented using BigInteger, e.g. static final BigInteger bigMin = BigInteger.valueOf(Long.MIN_VALUE); static final BigInteger bigMax = BigInteger.valueOf(Long.MAX_VALUE); long saturatedAdd(long x, long y) { BigInteger sum = BigInteger.valueOf(x).add(BigInteger.valueOf(y)); return bigMin.max(sum).min(bigMax).longValue(); } however performance is important so this method is not ideal (though useful for testing.) I don't know whether avoiding branching can significantly affect performance in Java. I assume it can, but I would like to benchmark methods both with and without branching. Related: http://stackoverflow.com/questions/121240/saturating-addition-in-c

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  • Computer science textbooks

    - by Barrett Conrad
    I would like to try the book question a little bit differently. My goal is to know what the community thinks are the quintessential computer science textbooks. <beginsadstory>I lost all of my computer science and math books from college in Hurricane Katrina in 2005. I greatly miss having my familiar tomes to refer to when topics and problems come up, so I am looking to rebuild my library.<endsadstory> What are your recommendations for the best examples of academic caliber books for the field of computer science and its associated mathematics? I am looking for books on subjects like computational theory, programming languages, compilers, operating systems, algorithms and so on. Don't limit your suggestions to your textbooks only. If there is a book you have read that covers computer science or a related math in a formal way, but is not strictly a textbook, I would be love to hear about them as well. Finally, for the sake of creating a good reference for all of us, may I suggest posting one book per answer so they can be rated individually.

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  • Fuzzy Date algorithm in Objective-C

    - by Brock Woolf
    I would like to write a fuzzy date method for calculating dates in Objective-C for iPhone. There is a popular explanation here: http://stackoverflow.com/questions/11/how-do-i-calculate-relative-time However it contains missing arguments. How could this be used in Objective-C?. Thanks. const int SECOND = 1; const int MINUTE = 60 * SECOND; const int HOUR = 60 * MINUTE; const int DAY = 24 * HOUR; const int MONTH = 30 * DAY; if (delta < 1 * MINUTE) { return ts.Seconds == 1 ? "one second ago" : ts.Seconds + " seconds ago"; } if (delta < 2 * MINUTE) { return "a minute ago"; } if (delta < 45 * MINUTE) { return ts.Minutes + " minutes ago"; } if (delta < 90 * MINUTE) { return "an hour ago"; } if (delta < 24 * HOUR) { return ts.Hours + " hours ago"; } if (delta < 48 * HOUR) { return "yesterday"; } if (delta < 30 * DAY) { return ts.Days + " days ago"; } if (delta < 12 * MONTH) { int months = Convert.ToInt32(Math.Floor((double)ts.Days / 30)); return months <= 1 ? "one month ago" : months + " months ago"; } else { int years = Convert.ToInt32(Math.Floor((double)ts.Days / 365)); return years <= 1 ? "one year ago" : years + " years ago"; }

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  • How can I make an AdvancedDataGrid re-display its labels when the results of the labelFunction chang

    - by Chris R
    I have an AdvancedDataGrid with a custom label function whose value can change based on other form status (specifically, there's a drop down to choose the time display format for some columns). Right now, I have this labelFunction: internal function formatColumnTime(item: Object, column: AdvancedDataGridColumn): String { var seconds: Number = item[column.dataField]; return timeFormat.selectedItem.labelFunction(seconds); } internal function formatTimeAsInterval(time: Number): String { if (isNaN(time)) return ""; var integerTime: int = Math.round(time); var seconds: int = integerTime % 60; integerTime = integerTime / 60; var minutes: int = integerTime % 60; var hours: int = integerTime / 60; return printf("%02d:%02d:%02d", hours, minutes, seconds); } internal function formatTimeAsFractions(time: Number): String { if (isNaN(time)) return ""; var hours: Number = time / 3600.0; return new String(Math.round(hours * 100) / 100); } ... and the timeFormat object is a combo box with items whose labelFunction attributes are formatTimeAsFractions and formatTimeAsInterval. The columns that have time formats have formatColumnTime as their labelFunction value, because extracting the seconds in that function and passing it in to the formatters made for a more testable app (IMHO). So, when the timeFormat.selectedItem value changes, I want to force my grid to re-calculate the labels of these colums. What method must I call on it? invalidateProperties() didn't work, so that's out.

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  • Rendering LaTeX on third-party websites

    - by A. Rex
    There are some sites on the web that render LaTeX into some more readable form, such as Wikipedia, some Wordpress blogs, and MathOverflow. They may use images, MathML, jsMath, or something like that. There are other sites on the web where LaTeX appears inline and is not rendered, such as the arXiv, various math forums, or my email. In fact, it is quite common to see an arXiv paper's abstract with raw LaTeX in it, e.g. this paper. Is there a plugin available for Firefox, or would it be possible to write one, that renders LaTeX within pages that do not provide a rendering mechanism themselves? Some notes: It may be impossible to render some of the code, because authors often copy-paste code directly from their source TeX files, which may contain things like "\cite{foo}" or undefined commands. These should be left alone. This question is a repost of a question from MathOverflow that was closed for not being related to math. I program a lot, but Javascript is not my specialty, so comments along the lines of "look at this library" are not particularly helpful to me (but may be to others).

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  • Use jquery to create a multidimensional array

    - by Simon M White
    I'd like to use jquery and a multidemensional array to show a random quote plus the name of the individual who wrote it as a separate item. I'll then be able to use css to style them differently. The quote will change upon page refresh. So far i have this code which combines the quote and the name and person who wrote it: $(document).ready(function(){ var myQuotes = new Array(); myQuotes[0] = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec in tortor mauris. Peter Jones, Dragons Den"; myQuotes[1] = "Curabitur interdum, nibh et fringilla facilisis, lacus ipsum pulvinar mauris, eu facilisis justo arcu eget diam. Duis id sagittis elit. Theo Pathetis, Dragons Den"; myQuotes[2] = "Vivamus purus purus, tincidunt et porttitor et, euismod sit amet urna. Etiam sollicitudin eros nec metus pretium scelerisque. James Caan, Dragons Den"; var myRandom = Math.floor(Math.random()*myQuotes.length); $('.quote-holder blockquote span').html(myQuotes[myRandom]); }); any help would be greatly appreciated.

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  • define javascript functions on iframe facebook app inside <fb:serverfbml> tag

    - by user233486
    Hi all, How we can define JS function on inside ? I tried to load file javascript on the end tag , but I still can't call the function from javascript file. Here the FBML tag <fb:serverfbml> <script type="text/fbml"> <fb:fbml> <a href="#" id="this" onclick="do_colors(this); return false">Hello World!</a> <script src="http://absolute.path.to/your/javascript/file.js"></script> </fb:fbml> </script> </fb:serverfbml> And here the javacript function on file.js function random_int(lo, hi) { return Math.floor((Math.random() * (hi - lo)) + lo) } function do_colors(obj) { var r = random_int(0, 255), b = random_int(0, 255), g = random_int(0, 255); obj.setStyle({background: 'rgb('+[r, g, b].join(',')+')', color: 'rgb('+[r<128?r+128:r-128, g<128?g+128:g-128, b<128?b+128:b-128].join(',')+')'}); } I use rails and facebooker to develop the application Any idea or suggestion for define javascript functions? Thanks,

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  • What is the best way to parse python script file in C/C++ code

    - by alexpov
    I am embedding python in C/C++ program. What I am trying to do is to parse the python script file from the C/C++ program, break the file to "blocks" so that each "block" is an a valid command in python code. Each block I need to put into std::string. For example: #PythonScript.py import math print "Hello Python" i = 0; while (i < 10): print "i = " , i; i = i + 1; print "GoodBye Python" In this script are 5 different "blocks": the first one is "import math;" the second is "print "Hello Python;" the third is "i = 0;" and the fourth is while (i < 10):\n\tprint "i = " , i;\n\ti = i + 1; My knowledge in python is very basic and I am not familiar with the python code syntax. What is the best way to do this, is there any Python C/C++ API function that supports this? why i need it - for GUI purpose. My program , which is writen in C, uses python to make some calculations. I run from C code , using python C API , python script and what i need is a way to capture python's output in my program. I catch it and evrything is ok, the problem is when the script involves user input. What happens is that i capture python's output after the script is finished , therefore, when there is an input command in the script i get a black screen .... i need to get all the printings before the input command. The first solution i tried is to parss the script to valid commands and run each comand, one after the other , seperatly .... for this i need to pars the script and deside what is a command and what is not ... The question is : what is the best way to do this and if there is somthing that allready does ?

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  • What are some funny loading statements to keep users amused?

    - by Oli
    Nobody likes waiting but unfortunately in the Ajax application I'm working on at the moment, there is one fair-sized pause (1-2 seconds a go) that users have to undergo each and every time they want to load up a chunk of data. I've tried to make the load as interactive as possible. There's an animated GIF alongside a very plain, very dull "Loading..." message. So I thought it might be quite fun to come up with a batch of 50-or-so funny-looking messages and pick from them randomly so the user never knows what they're going to see. The time they would have spent growing impatient is fruitfully used. Here's what I've come up with so far, just to give you an idea. var randomLoadingMessage = function() { var lines = new Array( "Locating the required gigapixels to render...", "Spinning up the hamster...", "Shovelling coal into the server...", "Programming the flux capacitor" ); return lines[Math.round(Math.random()*(lines.length-1))]; } (Yes -- I know some of those are pretty lame -- That's why I'm here :) The funniest I see today will get the prestigious "Accepted Answer" award. Others get votes for participation. Enjoy!!

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  • Project Euler 7 Scala Problem

    - by Nishu
    I was trying to solve Project Euler problem number 7 using scala 2.8 First solution implemented by me takes ~8 seconds def problem_7:Int = { var num = 17; var primes = new ArrayBuffer[Int](); primes += 2 primes += 3 primes += 5 primes += 7 primes += 11 primes += 13 while (primes.size < 10001){ if (isPrime(num, primes)) primes += num if (isPrime(num+2, primes)) primes += num+2 num += 6 } return primes.last; } def isPrime(num:Int, primes:ArrayBuffer[Int]):Boolean = { // if n == 2 return false; // if n == 3 return false; var r = Math.sqrt(num) for (i <- primes){ if(i <= r ){ if (num % i == 0) return false; } } return true; } Later I tried the same problem without storing prime numbers in array buffer. This take .118 seconds. def problem_7_alt:Int = { var limit = 10001; var count = 6; var num:Int = 17; while(count < limit){ if (isPrime2(num)) count += 1; if (isPrime2(num+2)) count += 1; num += 6; } return num; } def isPrime2(n:Int):Boolean = { // if n == 2 return false; // if n == 3 return false; var r = Math.sqrt(n) var f = 5; while (f <= r){ if (n % f == 0) { return false; } else if (n % (f+2) == 0) { return false; } f += 6; } return true; } I tried using various mutable array/list implementations in Scala but was not able to make solution one faster. I do not think that storing Int in a array of size 10001 can make program slow. Is there some better way to use lists/arrays in scala?

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  • Need help figuring out scala compiler errors.

    - by klactose
    Hello all, I have been working on a project in scala, but I am getting some error messages that I don't quite understand. The classes that I am working with are relatively simple. For example: abstract class Shape case class Point(x: Int, y: Int) extends Shape case class Polygon(points: Point*) extends Shape Now suppose that I create a Polygon: val poly = new Polygon(new Point(2,5), new Point(7,0), new Point(3,1)) Then if I attempt to determine the location and size of the smallest possible rectangle that could contain the polygon, I get various errors that I don't quite understand. Below are snippets of different attempts and the corresponding error messages that they produce. val upperLeftX = poly.points.reduceLeft(Math.min(_.x, _.x)) Gives the error: "missing parameter type for expanded function ((x$1) = x$1.x)" val upperLeftX = poly.points.reduceLeft((a: Point, b: Point) => (Math.min(a.x, b.x))) Gives this error: "type mismatch; found : (Point, Point) = Int required: (Any, Point) = Any" I am very confused about both of these error messages. If anyone could explain more clearly what I am doing incorrectly, I would really appreciate it. Yes, I see that the second error says that I need type "Any" but I don't understand exactly how to implement a change that would work as I need it. Obviously simply changing "a: Point" to "a: Any" is not a viable solution, so what am I missing?

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  • Why does Clojure hang after hacing performed my calculations?

    - by Thomas
    Hi all, I'm experimenting with filtering through elements in parallel. For each element, I need to perform a distance calculation to see if it is close enough to a target point. Never mind that data structures already exist for doing this, I'm just doing initial experiments for now. Anyway, I wanted to run some very basic experiments where I generate random vectors and filter them. Here's my implementation that does all of this (defn pfilter [pred coll] (map second (filter first (pmap (fn [item] [(pred item) item]) coll)))) (defn random-n-vector [n] (take n (repeatedly rand))) (defn distance [u v] (Math/sqrt (reduce + (map #(Math/pow (- %1 %2) 2) u v)))) (defn -main [& args] (let [[n-str vectors-str threshold-str] args n (Integer/parseInt n-str) vectors (Integer/parseInt vectors-str) threshold (Double/parseDouble threshold-str) random-vector (partial random-n-vector n) u (random-vector)] (time (println n vectors (count (pfilter (fn [v] (< (distance u v) threshold)) (take vectors (repeatedly random-vector)))))))) The code executes and returns what I expect, that is the parameter n (length of vectors), vectors (the number of vectors) and the number of vectors that are closer than a threshold to the target vector. What I don't understand is why the programs hangs for an additional minute before terminating. Here is the output of a run which demonstrates the error $ time lein run 10 100000 1.0 [null] 10 100000 12283 [null] "Elapsed time: 3300.856 msecs" real 1m6.336s user 0m7.204s sys 0m1.495s Any comments on how to filter in parallel in general are also more than welcome, as I haven't yet confirmed that pfilter actually works.

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  • Flash as3 smooth threshold

    - by arkzai
    hello, I'm building a flash app that pulls images from flickr and removes the white background I'm dong this using threshold and i get a really ragged outcome is there any way to get a better and smoother color key? thanks photoNumber = Math.floor(Math.random() * (photos.length)); loader.load(new URLRequest(photos[photoNumber].path)); loader.contentLoaderInfo.addEventListener(Event.COMPLETE,draw); trace ( "trying to load photo " + photoNumber ); function draw(e:Event) { trace ("show photo " + photoNumber) var W:int=e.target.content.width; var H:int=e.target.content.height; bitmapdata=new BitmapData(W,H); bitmap=new Bitmap(bitmapdata); bitmapdata.draw(e.target.content); var threshold:uint = 0xF9F8F800; var color:uint = 0x00000000; var maskColor:uint = 0x00FF0000; bitmapdata.threshold(bitmapdata,new Rectangle(0,0,W,H),new Point(0,0),">", threshold, color, maskColor, true); bitmap.smoothing = true; //bitmap.scaleX = bitmap.scaleY = 0.99; // <---- imgHolder.addChild(bitmap); } }

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  • Can a function return an object? Objective-C and NSMutableArray

    - by seaworthy
    I have an NSMutableArray. It's members eventually become members of an array instance in a class. I want to put the instantiantion of NSMutable into a function and to return an array object. If I can do this, I can make some of my code easier to read. Is this possible? Here is what I am trying to figure out. //Definition: > function Objects (float a, float b) { > NSMutableArray *array = [[NSMutableArray alloc] init]; > [array addObject:[NSNumber numberWithFloat:a]]; > [array addObject:[NSNumber numberWithFloat:b]]; > //[release array]; ???????? return array; > } //Declaration: Math *operator = [[Math alloc] init]; [operator findSum:Objects(20.0,30.0)]; My code compiles if I instantiate NSMutableArray right before I send the message to the receiver. I know I can have an array argument along with the method. What I have problem seeing is how to use a function and to replace the argument with a function call. Any help is appreciated. I am interested in the concept not in suggestions to replace the findSum method.

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  • Iterative Cartesian Product in Java

    - by akappa
    Hi, I want to compute the cartesian product of an arbitrary number of nonempty sets in Java. I've wrote that iterative code... public static <T> List<Set<T>> cartesianProduct(List<Set<T>> list) { List<Iterator<T>> iterators = new ArrayList<Iterator<T>>(list.size()); List<T> elements = new ArrayList<T>(list.size()); List<Set<T>> toRet = new ArrayList<Set<T>>(); for (int i = 0; i < list.size(); i++) { iterators.add(list.get(i).iterator()); elements.add(iterators.get(i).next()); } for (int j = 1; j >= 0;) { toRet.add(Sets.newHashSet(elements)); for (j = iterators.size()-1; j >= 0 && !iterators.get(j).hasNext(); j--) { iterators.set(j, list.get(j).iterator()); elements.set(j, iterators.get(j).next()); } elements.set(Math.abs(j), iterators.get(Math.abs(j)).next()); } return toRet; } ...but I found it rather inelegant. Someone has a better, still iterative solution? A solution that uses some wonderful functional-like approach? Otherwise... suggestion about how to improve it? Errors? Thanks :)

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  • Rails undefined method 'generated_methods' for nil:NilClass

    - by mike
    Okay so I was just starting this rails app and generated my first model ruby script/generate model Grid req:string class:string ctitle:string credits:float grade:string pass:boolean created my table rake db:migrate (in C:/Users/Michael/InstantRails/rails_apps/studentGrid) == CreateGrids: migrating ==================================================== -- create_table(:grids) - 0.0150s == CreateGrids: migrated (0.0150s) =========================================== and went to the console to add some data to my table Grid = Grid(id: integer, req: string, class: string, ctitle: string, credits: float, grade: string, pass: boolean, created_at: datetime, updated_at: datetime) Grid.create(:req="Math Elective", :class="Math 111", :ctitle="Calculus I", :credits=3.0) Pretty standard I thought, but then I get this error and I don't understand why NoMethodError: undefined method 'generated_methods' for nil:NilClass from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activesup port-2.3.5/lib/active_support/whiny_nil.rb:52:inmethod_missing' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/attribute_methods.rb:352:in respond_to?' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/base.rb:2746:inattributes=' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/base.rb:2742:in each' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/base.rb:2742:inattributes=' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/base.rb:2438:in initialize' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/base.rb:721:innew' from C:/Users/Michael/InstantRails/ruby/lib/ruby/gems/1.8/gems/activerec ord-2.3.5/lib/active_record/base.rb:721:in `create' from (irb):2 from :0

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  • Rendering LaTeX on third-party websites?

    - by A. Rex
    There are some sites on the web that render LaTeX into some more readable form, such as Wikipedia, some Wordpress blogs, and MathOverflow. They may use images, MathML, jsMath, or something like that. There are other sites on the web where LaTeX appears inline and is not rendered, such as the arXiv, various math forums, or my email. In fact, it is quite common to see an arXiv paper's abstract with raw LaTeX in it, e.g. this paper. Is there a plugin available for Firefox, or would it be possible to write one, that renders LaTeX within pages that do not provide a rendering mechanism themselves? (The LaTeX would be enclosed within dollar signs, e.g. $\pi$. See the arXiv link above.) Some notes: It may be impossible to render some of the code, because authors often copy-paste code directly from their source TeX files, which may contain things like "\cite{foo}" or undefined commands. These should be left alone. This question is a repost of a question from MathOverflow that was closed for not being related to math. There is one answer there, which is helpful, but perhaps Stack Overflow can provide better answers. I program a lot, but Javascript is not my specialty, so comments along the lines of "look at this library" are not particularly helpful to me (but may be to others).

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  • Autocompleting \cite{} with emacs + auctex gives "cite: no such database entry"

    - by Alejandro Weinstein
    Hi: I am running Emacs 23.1.1 and AucTeX 11.85 in an Ubuntu 8.10 machine. After opening a tex file, the first time I try to use the autocompletion of the \cite{} command, I get "cite: info not available, use `C-c &' to get it." in the minibuffer. After doing the 'C-c &', I get "byte-code: No BibTeX entry with citation key". Subsequent calls to \cite gives me the message "cite: no such database entry" . I have a \bibliography{library} in my tex file, and the \cite{} entries that I did manually work as expected. I have the following in my .emacs (require 'reftex) (setq-default TeX-master nil) (add-hook 'LaTeX-mode-hook 'TeX-PDF-mode) ;turn on pdf-mode. AUCTeX ;will call pdflatex to ;compile instead of latex. (add-hook 'LaTeX-mode-hook 'LaTeX-math-mode) ;turn on math-mode by ;default (add-hook 'LaTeX-mode-hook 'reftex-mode) ;turn on REFTeX mode by ;default (add-hook 'LaTeX-mode-hook 'flyspell-mode) ;turn on flyspell mode by ;default (setq reftex-plug-into-AUCTeX t) (setq TeX-auto-save t) (setq TeX-save-query nil) (setq TeX-parse-self t) (setq-default TeX-master nil) I also tried the suggestions in http://stackoverflow.com/questions/2699017/suggestion-for-cite-in-emacs-with-auctex, but it didn't work either. Alejandro.

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  • printing out prime numbers from array

    - by landscape
    I'd like to print out all prime numbers from an array with method. I can do it with one int but don't know how to return certain numbers from array. Thanks for help! public static boolean isPrime(int [] tab) { boolean prime = true; for (int i = 3; i <= Math.sqrt(tab[i]); i += 2) if (tab[i] % i == 0) { prime = false; break; } for(int i=0; i<tab.length; i++) if (( tab[i]%2 !=0 && prime && tab[i] > 2) || tab[i] == 2) { return true; } else { return false; } //return prime; } thanks both of you. Seems like its solved: public static void isPrime(int[] tab) { for (int i = 0; i < tab.length; i++) { if (isPrimeNum(tab[i])) { System.out.println(tab[i]); } } } public static boolean isPrimeNum(int n) { boolean prime = true; for (long i = 3; i <= Math.sqrt(n); i += 2) { if (n % i == 0) { prime = false; break; } } if ((n % 2 != 0 && prime && n > 2) || n == 2) { return true; } else { return false; } }

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  • accessing object variables in javascript

    - by user1452370
    So, I just started javascript and everything was working fine till i came to objects. This peace of code is supposed to create a bouncing ball in a html canvas with javascript but it doesn't work. var canvas = document.getElementById("myCanvas"); var ctx = canvas.getContext("2d"); //clear function clear() { ctx.clearRect(0, 0, canvas.width, canvas.height); } here is my ball object //ball var ball = { x: canvas.width / 2, getX: function() { return x; }, setX: function(a) { x = a; }, y: canvas.height / 2, getY: function() { return y; }, setY: function(a) { y = a; }, mx: 2, getMx: function() { return mx; }, my: 4, getMy: function() { return my; }, r: 10, getR: function() { return r; } }; code to draw my ball function drawBall() { ctx.beginPath(); ctx.arc(ball.getX, ball.getY, ball.getR, 0, Math.PI * 2, true); ctx.fillStyle = "#83F52C"; ctx.fill(); } function circle(x, y, r) { ctx.beginPath(); ctx.arc(x, y, r, 0, Math.PI * 2, true); ctx.fillStyle = "#83F52C"; ctx.fill(); } //draws ball and updates x,y cords function draw() { clear(); drawBall(); if (ball.getX() + ball.getMx() >= canvas.width || ball.getX()+ ball.getMx() <= 0) { ball.setMx(-ball.getMx()); } if (ball.getY() + ball.getMy() >= canvas.height|| ball.getY()+ ball.getMy() <= 0) { ball.setMy(-ball.getMy()); } ball.setX(ball.getX() + ball.getMx()); ball.setY(ball.getY() + ball.getMy()); } set interval function init() { return setInterval(draw, 10); } init();

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  • Getting started with massive data

    - by Max
    I'm a math guy and occasionally do some statistics/machine learning analysis consulting projects on the side. The data I have access to are usually on the smaller side, at most a couple hundred of megabytes (and almost always far less), but I want to learn more about handling and analyzing data on the gigabyte/terabyte scale. What do I need to know and what are some good resources to learn from? Hadoop/MapReduce is one obvious start. Is there a particular programming language I should pick up? (I primarily work now in Python, Ruby, R, and occasionally Java, but it seems like C and Clojure are often used for large-scale data analysis?) I'm not really familiar with the whole NoSQL movement, except that it's associated with big data. What's a good place to learn about it, and is there a particular implementation (Cassandra, CouchDB, etc.) I should get familiar with? Where can I learn about applying machine learning algorithms to huge amounts of data? My math background is mostly on the theory side, definitely not on the numerical or approximation side, and I'm guessing most of the standard ML algorithms don't really scale. Any other suggestions on things to learn would be great!

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