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  • compare two following values in numpy array

    - by Billy Mitchell
    What is the best way to touch two following values in an numpy array? example: npdata = np.array([13,15,20,25]) for i in range( len(npdata) ): print npdata[i] - npdata[i+1] this looks really messed up and additionally needs exception code for the last iteration of the loop. any ideas? Thanks!

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  • Java - get index of key in HashMap?

    - by llm
    In java if I am looping over the keySet() of a HashMap, how do I (inside the loop), get the numerical index of that key? Basically, as I loop through the map, I want to be able to get 0,1,2...I figure this would be cleaner than declaring an int and incrementing with each iteration. Thanks.

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  • Feedback on iterating over type-safe enums

    - by Sumant
    In response to the earlier SO question "Enumerate over an enum in C++", I came up with the following reusable solution that uses type-safe enum idiom. I'm just curious to see the community feedback on my solution. This solution makes use of a static array, which is populated using type-safe enum objects before first use. Iteration over enums is then simply reduced to iteration over the array. I'm aware of the fact that this solution won't work if the enumerators are not strictly increasing. template<typename def, typename inner = typename def::type> class safe_enum : public def { typedef typename def::type type; inner val; static safe_enum array[def::end - def::begin]; static bool init; static void initialize() { if(!init) // use double checked locking in case of multi-threading. { unsigned int size = def::end - def::begin; for(unsigned int i = 0, j = def::begin; i < size; ++i, ++j) array[i] = static_cast<typename def::type>(j); init = true; } } public: safe_enum(type v = def::begin) : val(v) {} inner underlying() const { return val; } static safe_enum * begin() { initialize(); return array; } static safe_enum * end() { initialize(); return array + (def::end - def::begin); } bool operator == (const safe_enum & s) const { return this->val == s.val; } bool operator != (const safe_enum & s) const { return this->val != s.val; } bool operator < (const safe_enum & s) const { return this->val < s.val; } bool operator <= (const safe_enum & s) const { return this->val <= s.val; } bool operator > (const safe_enum & s) const { return this->val > s.val; } bool operator >= (const safe_enum & s) const { return this->val >= s.val; } }; template <typename def, typename inner> safe_enum<def, inner> safe_enum<def, inner>::array[def::end - def::begin]; template <typename def, typename inner> bool safe_enum<def, inner>::init = false; struct color_def { enum type { begin, red = begin, green, blue, end }; }; typedef safe_enum<color_def> color; template <class Enum> void f(Enum e) { std::cout << static_cast<unsigned>(e.underlying()) << std::endl; } int main() { std::for_each(color::begin(), color::end(), &f<color>); color c = color::red; }

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  • Is recursion ever faster than looping?

    - by Carson Myers
    I know that recursion is sometimes a lot cleaner than looping, and I'm not asking anything about when I should use recursion over iteration, I know there are lots of questions about that already. What I'm asking is, is recursion ever faster than a loop? To me it seems like, you would always be able to refine a loop and get it to perform more quickly than a recursive function because the loop is absent constantly setting up new stack frames. I'm specifically looking for whether recursion is faster in applications where recursion is the right way to handle the data, such as in some sorting functions, in binary trees, etc.

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  • (C#) iterate over read-only private collection member

    - by DGH
    I have a class which has two HashSet collections as private members. Other classes in my code would like to be able to iterate over those HashSets and read their contents. I don't want to write a standard getter because another class could still do something like myClass.getHashSet().Clear(); Is there any other way to expose the elements of my HashSets to iteration without exposing the reference to the HashSet itself? I'd love to be able to do this in a way that is compatible with for-each loops.

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  • Lua - Iterate Through Table With nil Values

    - by Tony Trozzo
    My lua function receives a table that is of the array form: { field1, field2, nil, field3, } No keys, only values. I'm trying to convert this to a pseudo CSV form by grabbing all the fields and concatenating them into a string. Here is my function: function ArenaRewind:ConvertToCSV(tableName) csvRecord = "\n" for i,v in pairs(tableName) do if v == nil then v = "nil" end csvRecord = csvRecord .. "\"" .. v .. "\"" if i ~= #tableName then csvRecord = csvRecord .. "," end end return csvRecord end Not the prettiest code by any means, but it seems to iterate through them and grab all the non-nil values. The other table iteration function is ipairs() which stops as soon as it hits a nil value. Is there any easy way to grab all of these fields including the nil values? The tables are various sizes, so I hope to refrain from accessing each part like an array [i.e., tableName[1] through tableName[4]) and just grabbing the nil values that way. Thanks in advance.

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  • What statistics can be maintained for a set of numerical data without iterating?

    - by Dan Tao
    Update Just for future reference, I'm going to list all of the statistics that I'm aware of that can be maintained in a rolling collection, recalculated as an O(1) operation on every addition/removal (this is really how I should've worded the question from the beginning): Obvious Count Sum Mean Max* Min* Median** Less Obvious Variance Standard Deviation Skewness Kurtosis Mode*** Weighted Average Weighted Moving Average**** OK, so to put it more accurately: these are not "all" of the statistics I'm aware of. They're just the ones that I can remember off the top of my head right now. *Can be recalculated in O(1) for additions only, or for additions and removals if the collection is sorted (but in this case, insertion is not O(1)). Removals potentially incur an O(n) recalculation for non-sorted collections. **Recalculated in O(1) for a sorted, indexed collection only. ***Requires a fairly complex data structure to recalculate in O(1). ****This can certainly be achieved in O(1) for additions and removals when the weights are assigned in a linearly descending fashion. In other scenarios, I'm not sure. Original Question Say I maintain a collection of numerical data -- let's say, just a bunch of numbers. For this data, there are loads of calculated values that might be of interest; one example would be the sum. To get the sum of all this data, I could... Option 1: Iterate through the collection, adding all the values: double sum = 0.0; for (int i = 0; i < values.Count; i++) sum += values[i]; Option 2: Maintain the sum, eliminating the need to ever iterate over the collection just to find the sum: void Add(double value) { values.Add(value); sum += value; } void Remove(double value) { values.Remove(value); sum -= value; } EDIT: To put this question in more relatable terms, let's compare the two options above to a (sort of) real-world situation: Suppose I start listing numbers out loud and ask you to keep them in your head. I start by saying, "11, 16, 13, 12." If you've just been remembering the numbers themselves and nothing more, and then I say, "What's the sum?", you'd have to think to yourself, "OK, what's 11 + 16 + 13 + 12?" before responding, "52." If, on the other hand, you had been keeping track of the sum yourself while I was listing the numbers (i.e., when I said, "11" you thought "11", when I said "16", you thought, "27," and so on), you could answer "52" right away. Then if I say, "OK, now forget the number 16," if you've been keeping track of the sum inside your head you can simply take 16 away from 52 and know that the new sum is 36, rather than taking 16 off the list and them summing up 11 + 13 + 12. So my question is, what other calculations, other than the obvious ones like sum and average, are like this? SECOND EDIT: As an arbitrary example of a statistic that (I'm almost certain) does require iteration -- and therefore cannot be maintained as simply as a sum or average -- consider if I asked you, "how many numbers in this collection are divisible by the min?" Let's say the numbers are 5, 15, 19, 20, 21, 25, and 30. The min of this set is 5, which divides into 5, 15, 20, 25, and 30 (but not 19 or 21), so the answer is 5. Now if I remove 5 from the collection and ask the same question, the answer is now 2, since only 15 and 30 are divisible by the new min of 15; but, as far as I can tell, you cannot know this without going through the collection again. So I think this gets to the heart of my question: if we can divide kinds of statistics into these categories, those that are maintainable (my own term, maybe there's a more official one somewhere) versus those that require iteration to compute any time a collection is changed, what are all the maintainable ones? What I am asking about is not strictly the same as an online algorithm (though I sincerely thank those of you who introduced me to that concept). An online algorithm can begin its work without having even seen all of the input data; the maintainable statistics I am seeking will certainly have seen all the data, they just don't need to reiterate through it over and over again whenever it changes.

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  • How can I iterate over a recordset within a stored procedure?

    - by David
    I need to iterate over a recordset from a stored procedure and execute another stored procedure using each fields as arguments. I can't complete this iteration in the code. I have found samples on the internets, but they all seem to deal with a counter. I'm not sure if my problem involved a counter. I need the T-SQL equivalent of a foreach Currently, my first stored procedure stores its recordset in a temp table, #mytemp. I assume I will call the secondary stored procedure like this: while (something) execute nameofstoredprocedure arg1, arg2, arg3 end

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  • In JSF, how to handle repeating over a list that mutates

    - by Jon
    Hello, In a JSF page, I am iterating over a list of items provided by a session-scoped backing bean. The list needs to be kept up-to-date, so it is replaced with a fresh list every X minutes by a thread (in a thread-safe way). On my page, for each item I provide some text inputs and an "Update" button. If the list is refreshed before I hit "Update", the update does not happen (which is my problem). I happen to be using a4j:repeat, but I think this could also apply to other methods of iteration, including using dataTables. Any thoughts on how I can do this in a non-hackish way? Thanks!

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  • Python performance: iteration and operations on nested lists

    - by J.J.
    Problem Hey folks. I'm looking for some advice on python performance. Some background on my problem: Given: A mesh of nodes of size (x,y) each with a value (0...255) starting at 0 A list of N input coordinates each at a specified location within the range (0...x, 0...y) Increment the value of the node at the input coordinate and the node's neighbors within range Z up to a maximum of 255. Neighbors beyond the mesh edge are ignored. (No wrapping) BASE CASE: A mesh of size 1024x1024 nodes, with 400 input coordinates and a range Z of 75 nodes. Processing should be O(x*y*Z*N). I expect x, y and Z to remain roughly around the values in the base case, but the number of input coordinates N could increase up to 100,000. My goal is to minimize processing time. Current results I have 2 current implementations: f1, f2 Running speed on my 2.26 GHz Intel Core 2 Duo with Python 2.6.1: f1: 2.9s f2: 1.8s f1 is the initial naive implementation: three nested for loops. f2 is replaces the inner for loop with a list comprehension. Code is included below for your perusal. Question How can I further reduce the processing time? I'd prefer sub-1.0s for the test parameters. Please, keep the recommendations to native Python. I know I can move to a third-party package such as numpy, but I'm trying to avoid any third party packages. Also, I've generated random input coordinates, and simplified the definition of the node value updates to keep our discussion simple. The specifics have to change slightly and are outside the scope of my question. thanks much! f1 is the initial naive implementation: three nested for loops. 2.9s def f1(x,y,n,z): rows = [] for i in range(x): rows.append([0 for i in xrange(y)]) for i in range(n): inputX, inputY = (int(x*random.random()), int(y*random.random())) topleft = (inputX - z, inputY - z) for i in xrange(max(0, topleft[0]), min(topleft[0]+(z*2), x)): for j in xrange(max(0, topleft[1]), min(topleft[1]+(z*2), y)): if rows[i][j] <= 255: rows[i][j] += 1 f2 is replaces the inner for loop with a list comprehension. 1.8s def f2(x,y,n,z): rows = [] for i in range(x): rows.append([0 for i in xrange(y)]) for i in range(n): inputX, inputY = (int(x*random.random()), int(y*random.random())) topleft = (inputX - z, inputY - z) for i in xrange(max(0, topleft[0]), min(topleft[0]+(z*2), x)): l = max(0, topleft[1]) r = min(topleft[1]+(z*2), y) rows[i][l:r] = [j+1 for j in rows[i][l:r] if j < 255]

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  • Fastest image iteration in Python

    - by Greg
    I am creating a simple green screen app with Python 2.7.4 but am getting quite slow results. I am currently using PIL 1.1.7 to load and iterate the images and saw huge speed-ups changing from the old getpixel() to the newer load() and pixel access object indexing. However the following loop still takes around 2.5 seconds to run for an image of around 720p resolution: def colorclose(Cb_p, Cr_p, Cb_key, Cr_key, tola, tolb): temp = math.sqrt((Cb_key-Cb_p)**2+(Cr_key-Cr_p)**2) if temp < tola: return 0.0 else: if temp < tolb: return (temp-tola)/(tolb-tola) else: return 1.0 .... for x in range(width): for y in range(height): Y, cb, cr = fg_cbcr_list[x, y] mask = colorclose(cb, cr, cb_key, cr_key, tola, tolb) mask = 1 - mask bgr, bgg, bgb = bg_list[x,y] fgr, fgg, fgb = fg_list[x,y] pixels[x,y] = ( (int)(fgr - mask*key_color[0] + mask*bgr), (int)(fgg - mask*key_color[1] + mask*bgg), (int)(fgb - mask*key_color[2] + mask*bgb)) Am I doing anything hugely inefficient here which makes it run so slow? I have seen similar, simpler examples where the loop is replaced by a boolean matrix for instance, but for this case I can't see a way to replace the loop. The pixels[x,y] assignment seems to take the most amount of time but not knowing Python very well I am unsure of a more efficient way to do this. Any help would be appreciated.

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  • Removing an Entity from an EntitySet during Iteration...

    - by Gregorius
    I've got this code... seems nice and elegant, but apparently the framework don't like it when i mess with a collection while iterating through it: foreach (KitGroup kg in ProductToTransfer.KitGroups) { // Remove kit groups that have been excluded by the user if (inKitGroupExclusions != null && inKitGroupExclusions.Contains(kg.KitGroupID)) ProductToTransfer.KitGroups.Remove(kg); else { // Loop through the kit items and do other stuff //... } } The error it throws when it iterates to the 2nd object in the collection is: "EntitySet was modified during enumeration" I know i could create a new collection of KitGroup objects (or even just IDs) that i want to remove, and then another loop afterwards to loop through these, and remove them from the collection, but this just seems like unnecessary extra code... can anybody suggest a more elegant way of achieving the same thing? Cheers Greg

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  • Iteration speed of int vs long

    - by jqno
    I have the following two programs: long startTime = System.currentTimeMillis(); for (int i = 0; i < N; i++); long endTime = System.currentTimeMillis(); System.out.println("Elapsed time: " + (endTime - startTime) + " msecs"); and long startTime = System.currentTimeMillis(); for (long i = 0; i < N; i++); long endTime = System.currentTimeMillis(); System.out.println("Elapsed time: " + (endTime - startTime) + " msecs"); Note: the only difference is the type of the loop variable (int and long). When I run this, the first program consistently prints between 0 and 16 msecs, regardless of the value of N. The second takes a lot longer. For N == Integer.MAX_VALUE, it runs in about 1800 msecs on my machine. The run time appears to be more or less linear in N. So why is this? I suppose the JIT-compiler optimizes the int loop to death. And for good reason, because obviously it doesn't do anything. But why doesn't it do so for the long loop as well? A colleague thought we might be measuring the JIT compiler doing its work in the long loop, but since the run time seems to be linear in N, this probably isn't the case.

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  • Changing POST data used by Apache Bench per iteration

    - by Alabaster Codify
    I'm using ab to do some load testing, and it's important that the supplied querystring (or POST) parameters change between requests. I.e. I need to make requests to URLs like: http://127.0.0.1:9080/meth?param=0 http://127.0.0.1:9080/meth?param=1 http://127.0.0.1:9080/meth?param=2 ... to properly exercise the application. ab seems to only read the supplied POST data file once, at startup, so changing its content during the test run is not an option. Any suggestions?

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  • Beginner - C# iteration through directory to produce a file list

    - by dassouki
    The end goal is to have some form of a data structure that stores a hierarchal structure of a directory to be stored in a txt file. I'm using the following code and so far, and I'm struggling with combining dirs, subdirs, and files. /// <summary> /// code based on http://msdn.microsoft.com/en-us/library/bb513869.aspx /// </summary> /// <param name="strFolder"></param> public static void TraverseTree ( string strFolder ) { // Data structure to hold names of subfolders to be // examined for files. Stack<string> dirs = new Stack<string>( 20 ); if ( !System.IO.Directory.Exists( strFolder ) ) { throw new ArgumentException(); } dirs.Push( strFolder ); while ( dirs.Count > 0 ) { string currentDir = dirs.Pop(); string[] subDirs; try { subDirs = System.IO.Directory.GetDirectories( currentDir ); } catch ( UnauthorizedAccessException e ) { MessageBox.Show( "Error: " + e.Message ); continue; } catch ( System.IO.DirectoryNotFoundException e ) { MessageBox.Show( "Error: " + e.Message ); continue; } string[] files = null; try { files = System.IO.Directory.GetFiles( currentDir ); } catch ( UnauthorizedAccessException e ) { MessageBox.Show( "Error: " + e.Message ); continue; } catch ( System.IO.DirectoryNotFoundException e ) { MessageBox.Show( "Error: " + e.Message ); continue; } // Perform the required action on each file here. // Modify this block to perform your required task. /* foreach ( string file in files ) { try { // Perform whatever action is required in your scenario. System.IO.FileInfo fi = new System.IO.FileInfo( file ); Console.WriteLine( "{0}: {1}, {2}", fi.Name, fi.Length, fi.CreationTime ); } catch ( System.IO.FileNotFoundException e ) { // If file was deleted by a separate application // or thread since the call to TraverseTree() // then just continue. MessageBox.Show( "Error: " + e.Message ); continue; } } */ // Push the subdirectories onto the stack for traversal. // This could also be done before handing the files. foreach ( string str in subDirs ) dirs.Push( str ); foreach ( string str in files ) MessageBox.Show( str ); }

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  • android circulate gallery iteration with 10 items.

    - by Faisal khan
    I am using the following customize gallery. I am having static 10 images, i want circulatery gallery which should circlate always should never ends after last item it should auto start by 1 or after first it should auto start from end. public class SizingGallery extends Gallery{ public SizingGallery(Context context, AttributeSet attrs) { super(context, attrs); } @Override protected boolean getChildStaticTransformation(View child, Transformation t) { t.clear(); ImageView selectedChild = (ImageView)getSelectedView(); ImageView iv =(ImageView)child; BrowseMapCategoryRow cr = (BrowseMapCategoryRow)iv.getTag(); if (iv == selectedChild) { selectedChild.setImageResource(cr.getSelectedImgSrc()); }else{ iv.setImageResource(cr.getUnSelectedImgSrc()); } return true; } @Override protected int getChildDrawingOrder(int childCount, int i) { return super.getChildDrawingOrder(childCount, i); } }

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  • Exception during iteration on collection and remove items from that collection

    - by Muhammad Kashif Nadeem
    I remove item from ArrayList in foreach loop and get follwing exception. Collection was modified; enumeration operation may not execute. How can I remove items in foreach Following is my code: /* * Need to remove all items from 'attachementsFielPath' which does not exist in names array. */ try { string attachmentFileNames = txtAttachment.Text.Trim(); // Textbox having file names. string[] names = attachmentFileNames.Split(new char[] { ';' }); int index = 0; // attachmentsFilePath is ArrayList holding full path of fiels user selected at any time. foreach (var fullFilePath in attachmentsFilePath) { bool isNeedToRemove = true; // Extract filename from full path. string fileName = fullFilePath.ToString().Substring(fullFilePath.ToString().LastIndexOf('\\') + 1); for (int i = 0; i < names.Length; i++) { // If filename found in array then no need to check remaining items. if (fileName.Equals(names[i].Trim())) { isNeedToRemove = false; break; } } // If file not found in names array, remove it. if (isNeedToRemove) { attachmentsFilePath.RemoveAt(index); isNeedToRemove = true; } index++; } } catch (Exception ex) { throw ex; }

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  • How to simply a foreach iteration using reflection

    - by Priya
    Consider that I have to get the overall performance of X. X has Y elements and Y in turn has Z elements which inturn has some N elements. To get the performance of X I do this: List<double> XQ = new List<double>(); foreach (Elem Y in X.Y){ List<double> YQ = new List<double>(); foreach (Elem Z in Y.Z){ List<double> ZQ = new List<double>(); foreach (Elem N in Z.N){ ZQ.Add(GetPerformance(N)); } YQ.Add(AVG(ZQ)); } XQ.Add(AVG(YQ)); } AVG of XQ list gives the performance of X. The performance can be calculated for either X or Y or for Z. X, Y and Z share the same base class. So depending on the item given the foreach loop has to be executed. Currently I have a switch case to determine each item (X or Y or Z) and the foreach loop is repeated in the code pertaining to the item (eg. If Y foreach starts from Y.Z). Is is possible to convert this whole code generic using reflection instead of having to repeat it in each switch case? Thanks

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  • Writing more efficient xquery code (avoiding redundant iteration)

    - by Coquelicot
    Here's a simplified version of a problem I'm working on: I have a bunch of xml data that encodes information about people. Each person is uniquely identified by an 'id' attribute, but they may go by many names. For example, in one document, I might find <person id=1>Paul Mcartney</person> <person id=2>Ringo Starr</person> And in another I might find: <person id=1>Sir Paul McCartney</person> <person id=2>Richard Starkey</person> I want to use xquery to produce a new document that lists every name associated with a given id. i.e.: <person id=1> <name>Paul McCartney</name> <name>Sir Paul McCartney</name> <name>James Paul McCartney</name> </person> <person id=2> ... </person> The way I'm doing this now in xquery is something like this (pseudocode-esque): let $ids := distinct-terms( [all the id attributes on people] ) for $id in $ids return <person id={$id}> { for $unique-name in distinct-values ( for $name in ( [all names] ) where $name/@id=$id return $name ) return <name>{$unique-name}</name> } </person> The problem is that this is really slow. I imagine the bottleneck is the innermost loop, which executes once for every id (of which there are about 1200). I'm dealing with a fair bit of data (300 MB, spread over about 800 xml files), so even a single execution of the query in the inner loop takes about 12 seconds, which means that repeating it 1200 times will take about 4 hours (which might be optimistic - the process has been running for 3 hours so far). Not only is it slow, it's using a whole lot of virtual memory. I'm using Saxon, and I had to set java's maximum heap size to 10 GB (!) to avoid getting out of memory errors, and it's currently using 6 GB of physical memory. So here's how I'd really like to do this (in Pythonic pseudocode): persons = {} for id in ids: person[id] = set() for person in all_the_people_in_my_xml_document: persons[person.id].add(person.name) There, I just did it in linear time, with only one sweep of the xml document. Now, is there some way to do something similar in xquery? Surely if I can imagine it, a reasonable programming language should be able to do it (he said quixotically). The problem, I suppose, is that unlike Python, xquery doesn't (as far as I know) have anything like an associative array. Is there some clever way around this? Failing that, is there something better than xquery that I might use to accomplish my goal? Because really, the computational resources I'm throwing at this relatively simple problem are kind of ridiculous.

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  • Pair-wise iteration in C# or sliding window enumerator

    - by f3lix
    If I have an IEnumerable like: string[] items = new string[] { "a", "b", "c", "d" }; I would like to loop thru all the pairs of consecutive items (sliding window of size 2). Which would be ("a","b"), ("b", "c"), ("c", "d") My solution was is this public static IEnumerable<Pair<T, T>> Pairs(IEnumerable<T> enumerable) { IEnumerator<T> e = enumerable.GetEnumerator(); e.MoveNext(); T current = e.Current; while ( e.MoveNext() ) { T next = e.Current; yield return new Pair<T, T>(current, next); current = next; } } // used like this : foreach (Pair<String,String> pair in IterTools<String>.Pairs(items)) { System.Out.PrintLine("{0}, {1}", pair.First, pair.Second) } When I wrote this code, I wondered if there are already functions in the .NET framework that do the same thing and do it not just for pairs but for any size tuples. IMHO there should be a nice way to do this kind of sliding window operations. I use C# 2.0 and I can imagine that with C# 3.0 (w/ LINQ) there are more (and nicer) ways to do this, but I'm primarily interested in C# 2.0 solutions. Though, I will also appreciate C# 3.0 solutions.

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  • Basic Array Iteration in Ruby

    - by michaelmichael
    What's a better way to traverse an array while iterating through another array? For example, if I have two arrays like the following: names = [ "Rover", "Fido", "Lassie", "Calypso"] breeds = [ "Terrier", "Lhasa Apso", "Collie", "Bulldog"] Assuming the arrays correspond with one another - that is, Rover is a Terrier, Fido is a Lhasa Apso, etc. - I'd like to create a dog class, and a new dog object for each item: class Dog attr_reader :name, :breed def initialize(name, breed) @name = name @breed = breed end end I can iterate through names and breeds with the following: index = 0 names.each do |name| dog = Dog.new("#{name}", "#{breeds[index]}") index = index.next end However, I get the feeling that using the index variable is the wrong way to go about it. What would be a better way?

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  • Python line file iteration and strange characters

    - by muckabout
    I have a huge gzipped text file which I need to read, line by line. I go with the following: for i, line in enumerate(codecs.getreader('utf-8')(gzip.open('file.gz'))): print i, line At some point late in the file, the python output diverges from the file. This is because lines are getting broken due to weird special characters that python thinks are newlines. When I open the file in 'vim', they are correct, but the suspect characters are formatted weirdly. Is there something I can do to fix this? I've tried other codecs including utf-16, latin-1. I've also tried with no codec. I looked at the file using 'od'. Sure enough, there are \n characters where they shouldn't be. But, the "wrong" ones are prepended by a weird character. I think there's some encoding here with some characters being 2-bytes, but the trailing byte being a \n if not viewed properly. If I replace: gzip.open('file.gz') With: os.popen('zcat file.gz') It works fine (and actually, quite faster). But, I'd like to know where I'm going wrong.

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  • Backbone.js Collection Iteration Using .each()

    - by the_archer
    I've been doing some Backbone.js coding and have come across a particular problem where I am having trouble iterating over the contents of a collection. The line Tasker_TodoList.each(this.addOne, this);in the addAll function in AppView is not executing properly for some reason, throwing the error: Uncaught TypeError: undefined is not a function the code in question is: $(function() { var Todo = Backbone.Model.extend({ defaults: { title: "Some Title...", status: 0 //not completed } }); var TodoList = Backbone.Collection.extend({ model: Todo, localStorage: new Store('tasker') }); var Tasker_TodoList = new TodoList(); var TodoView = Backbone.View.extend({ tagName: 'li', template: _.template($('#todoTemplate').html()), events: { 'click .delbtn': 'delTodo' }, initialize: function(){ console.log("a new todo initialized"); //this.model.on('change', this.render, this); }, render: function(){ this.$el.html(this.template(this.model.toJSON())); return this; }, delTodo: function(){ console.log("deleted todo"); } }); var AppView = Backbone.View.extend({ el: 'body', events: { 'click #addBtn': 'createOnClick' }, initialize: function(){ Tasker_TodoList.fetch(); Tasker_TodoList.on('add', this.addAll); console.log(Tasker_TodoList); }, addAll: function(){ $('#tasksList').html(''); console.log("boooooooma"); Tasker_TodoList.each(this.addOne, this); }, addOne: function(todo){ console.log(todo); }, createOnClick: function(){ Tasker_TodoList.create(); } }); var Tasker = new AppView(); }); can somebody help me in finding out what I am doing wrong? Thank you all for your help :-)

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  • AJAX XML reply node value iteration

    - by XpiritO
    Hi there, guys. I would really appreciate to get your help on this, as I can't seem to detect and solve the problem I'm having with an AJAX functionality on a site that I'm currently developing. I have a webform that makes an asynchronous call to a handler (.ashx) that delivers a XML response that is later processed by a Javascript client-side function that places it's contents into the user-interface. I'm attaching an example of the response generated by my handler, and what I would like to know is how can I get all the <body> element innerHTML (with the text and child nodes) contents to append it to a <span> element on the user-interface. Can anyone help me out with this? XML Response returned by the handler (checked via Firebug): <message> <content> <messageId>2</messageId> <from>Barack Obama</from> <fromMail>[email protected]</fromMail> <subject>Yes, we can... get World Peace</subject> <body>Hello, dear citizen. I'm sending you this message to invite you to join us! <a href="http://www.whitehouse.gov">Test link</a> Thank you for your time.</body> </content> </message> Client-side Javascript function to affect the user-interface innerHTML property with the data returned via AJAX: function GetMessageContentsCallback(args, resp) { //XML Parser try { //Internet Explorer xmlDoc = new ActiveXObject("Microsoft.XMLDOM"); xmlDoc.async = "false"; xmlDoc.loadXML(resp); } catch (e) { parser = new DOMParser(); xmlDoc = parser.parseFromString(resp, "text/xml"); } var msgReply = xmlDoc.getElementsByTagName('message')[0]; var ajaxRespondeBodyInnerHTML = msgReply.getElementsByTagName(body)[0].firstChild.nodeValue; //this currently only delivers inner text content, without the <a href... bit and subsequent text document.getElementById("bodySpan").innerHTML = ajaxRespondeBodyInnerHTML; }

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