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  • PHP: parse $_FILES[] data in multidimesional array

    - by superUntitled
    I having been looking around for an answer to this and have not found an answer anywhere, I am hoping someone has done this before! I have a form that allows for dynamic duplication of the form fields. The form allows for file uploads and text input, so the data is sent in both $_POST and $_FILES arrays. The the initial set of inputs look like this: <input type="text" name="primary[1][text]" /> <input type="file" name="primary[1][file]" /> <input type="text" class="a" name="secondary[1][text][]" /> <input type="file" name="secondary[1][file][]" /> When duplicated the fields are incremented, they look like this: <input type="text" name="primary[2][text]" /> <input type="file" name="primary[2][file]" /> <input type="text" class="a" name="secondary[2][text][]" /> <input type="file" name="secondary[2][file][]" /> To complicate matters, the "secondary" form fields can also be duplicated (thus the [] at the end of the secondary name array. How can I parse the posted $_FILES array? I have tried something like this: foreach ($_FILES['question'] as $f_num) { echo $f['file']['name']; } but I get an "Undefined index: file... " error.

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  • C Map String to Function

    - by Scriptonaut
    So, I'm making a Unix minishell, and have come to a roadblock. I need to be able to execute built-in functions, so I made a function: int exec_if_built_in(char **args) It takes an array of strings(the first being the command, and the rest being arguments). For non built-in commands I simply use something like execvp, however I need to find a way to map the first string to a function. I was thinking of making two arrays, one of strings, and another with their corresponding function pointers. However, since many of these functions will be different(return and accept different things), this approach won't work. I also thought of making an array of structs with a name property and a function pointer property, however once again due to the varied nature of the functions I'll be using, this won't work. So, what's the best way to execute a function based on the input of a string? How do I map a string to a certain function? I'm not very familiar with function pointers so I may be missing something. Thank you guys for the help :)

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  • PHP: parse $_FILES[] data in multidimesional array

    - by superUntitled
    Example form here: http://jsfiddle.net/superuntitled/uaTtx/1/ I have a form that allows for dynamic duplication of the form fields. The form allows for file uploads and text input, so the data is sent in both $_POST and $_FILES arrays. The the initial set of inputs look like this: <input type="text" name="question[1][text]" /> <input type="file" name="question[1][file]" /> <input type="text" class="a" name="answer[1][text][]" /> <input type="file" name="answer[1][file][]" /> When duplicated the fields are incremented, they look like this: <input type="text" name="question[2][text]" /> <input type="file" name="question[2][file]" /> <input type="text" class="a" name="answer[2][text][]" /> <input type="file" name="answer[2][file][]" /> To complicate matters, the "answer" form fields can also be duplicated (thus the [] at the end of the 'answer' name array. How can I parse the posted $_FILES array? I have tried something like this: foreach ($_FILES['question'] as $p_num) { echo $p_num['file']['name']; foreach ($_FILES['answer'] as $a_num) { echo $a_num['file']['name']; } } but I get an "Undefined index: file... " error. How can I parse out the posted values.

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  • Error logging/handling on application basis?

    - by Industrial
    Hi everybody, We have a web server that we're about to launch a number of applications on. On the server-level we have managed to work out the error handling with the help of Hyperic to notify the person who is in charge in the event of a database/memcached server is going down. However, we are still in the need of handling those eventual error and log events that happen on application level to improve the applications for our customers, before the customers notices. So, what's then a good solution to do this? Utilizing PHP:s own error log would quickly become cloggered if we would run a big number of applications at the same time. It's probably isn't the best option if you like structure. One idea is to build a off-site lightweight error-handling application that has a REST/JSON API that receives encrypted and serialized arrays of error messages and stores them into a database. Maybe it could, depending on the severity of the error also be directly inputted into our bug tracker. Could be a few well spent hours, but it seems like a quite fragile solution and I am sure that there's better more-reliable alternatives out there already. Thanks,

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  • looping array inside list in c#

    - by 3yoon af
    I have a list of array that contains multiple arrays. each array has 2 index .. First, I want to loop the list. Then i want to loop the array inside the list .. How can i do that ? I try to use this way, but it doesn't work ! foreach (string[] s in ArrangList1) { int freq1 = int.Parse(s[1]); foreach (string[] s1 in ArrangList) { int freq2 = int.Parse(s1[1]); if (freq1 < freq2) { backup = s; index1 = ArrangList1.IndexOf(s); index2 = ArrangList.IndexOf(s1); ArrangList[index1] = s1; ArrangList[index2] = s; } backup = null; } } it give me error in line 4.. I try to do the loop using other way .. but i don't know how to continue ! for (int i = 0; i < ArrangList1.Count; i++) { for (int j = 0; j < ArrangList1[i].Length; j++) { ArrangList1[i][1]; } } I use C# language .. Can someone help me, please?

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  • How to easily apply a function to a collection in C++

    - by Jesse Beder
    I'm storing images as arrays, templated based on the type of their elements, like Image<unsigned> or Image<float>, etc. Frequently, I need to perform operations on these images; for example, I might need to add two images, or square an image (elementwise), and so on. All of the operations are elementwise. I'd like get as close as possible to writing things like: float Add(float a, float b) { return a+b; } Image<float> result = Add(img1, img2); and even better, things like complex ComplexCombine(float a, float b) { return complex(a, b); } Image<complex> result = ComplexCombine(img1, img2); or struct FindMax { unsigned currentMax; FindMax(): currentMax(0) {} void operator(unsigned a) { if(a > currentMax) currentMax = a; } }; FindMax findMax; findMax(img); findMax.currentMax; // now contains the maximum value of 'img' Now, I obviously can't exactly do that; I've written something so that I can call: Image<float> result = Apply(img1, img2, Add); but I can't seem to figure out a generic way for it to detect the return type of the function/function object passed, so my ComplexCombine example above is out; also, I have to write a new one for each number of arguments I'd like to pass (which seems inevitable). Any thoughts on how to achieve this (with as little boilerplate code as possible)?

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

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

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  • Beginnerquestion: How to count amount of each number drawn in a Lottery and output it in a list?

    - by elementz
    I am writing this little Lottery application. Now the plan is, to count how often each number has been drawn during each iteration of the Lottery, and store this somewhere. My guess is that I would need to use a HashMap, that has 6 keys and increments the value by one everytime the respective keys number is drawn. But how would I accomplish this? My code so far: public void numberCreator() { // creating and initializing a Random generator Random rand = new Random(); // A HashMap to store the numbers picked. HashMap hashMap = new HashMap(); // A TreeMap to sort the numbers picked. TreeMap treeMap = new TreeMap(); // creating an ArrayList which will store the pool of availbale Numbers List<Integer>numPool = new ArrayList<Integer>(); for (int i=1; i<50; i++){ // add the available Numbers to the pool numPool.add(i); hashMap.put(nums[i], 0); } // array to store the lotto numbers int [] nums = new int [6]; for (int i =0; i < nums.length; i++){ int numPoolIndex = rand.nextInt(numPool.size()); nums[i] = numPool.get(numPoolIndex); // check how often a number has been called and store the new amount in the Map int counter = hashMap.get numPool.remove(numPoolIndex); } System.out.println(Arrays.toString(nums)); } Maybe someone can tell me if I have the right idea, or even how I would implement the map properly?

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  • [Rails3] How to do multiple many to many relationships between the same two tables.

    - by Kurt
    Hi. I have a model of a club where I want to model the two entities Meeting and Member. There are actually two many-to-many relationships between these entities though, as for any meeting a Member can either be a Speaker or a Guest. Now I am an OO thinker, so would normally just create the two classes and each one would just have two arrays of the other inside, but rails is making me think a bit more data centric here, so I realise I need to break these M2M relationships up with join tables Speakers and Guests which I have done, but now I am having trouble describing the relationships in the models. The two join table models both have "belongs_to :meeting" and "belongs_to :member" and I think that should be sufficient. I am not however sure about the Meeting and Member models though. Each one has "has_many :guests" and "has_many: speakers" but I am not sure if I also want to go: has_many :members, :through = :guests has_many :members, :through = :speakers But I suspect that this is like declaring two "members" that will clash. I also thought about: has_many :guests, :through = :guests has_many :speakers, :through = :speakers Does that make sense? How would ActiveRecord know that they are in fact Members? I have found heaps of examples of polymorphic m2m relationships and m2m relationships where 1 table references itself, but no good examples to help me mode this situation where two separate tables have two different m2m relationships. Anyone got any tips?

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  • Applying a function that may fail to all values in a list

    - by Egwor
    I want to apply a function f to a list of values, however function f might randomly fail (it is in effect making a call out to a service in the cloud). I thought I'd want to use something like map, but I want to apply the function to all elements in the list and afterwards, I want to know which ones failed and which were successful. Currently I am wrapping the response objects of the function f with an error pair which I could then effectively unzip afterwards i.e. something like g : (a->b) -> a -> [ b, errorBoolean] f : a-> b and then to run the code ... map g (xs) Is there a better way to do this? The other alternative approach was to iterate over the values in the array and then return a pair of arrays, one which listed the successful values and one which listed the failures. To me, this seems to be something that ought to be fairly common. Alternatively I could return some special value. What's the best practice in dealing with this??

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  • Optimizing near-duplicate value search

    - by GApple
    I'm trying to find near duplicate values in a set of fields in order to allow an administrator to clean them up. There are two criteria that I am matching on One string is wholly contained within the other, and is at least 1/4 of its length The strings have an edit distance less than 5% of the total length of the two strings The Pseudo-PHP code: foreach($values as $value){ foreach($values as $match){ if( ( $value['length'] < $match['length'] && $value['length'] * 4 > $match['length'] && stripos($match['value'], $value['value']) !== false ) || ( $match['length'] < $value['length'] && $match['length'] * 4 > $value['length'] && stripos($value['value'], $match['value']) !== false ) || ( abs($value['length'] - $match['length']) * 20 < ($value['length'] + $match['length']) && 0 < ($match['changes'] = levenshtein($value['value'], $match['value'])) && $match['changes'] * 20 <= ($value['length'] + $match['length']) ) ){ $matches[] = &$match; } } } I've tried to reduce calls to the comparatively expensive stripos and levenshtein functions where possible, which has reduced the execution time quite a bit. However, as an O(n^2) operation this just doesn't scale to the larger sets of values and it seems that a significant amount of the processing time is spent simply iterating through the arrays. Some properties of a few sets of values being operated on Total | Strings | # of matches per string | | Strings | With Matches | Average | Median | Max | Time (s) | --------+--------------+---------+--------+------+----------+ 844 | 413 | 1.8 | 1 | 58 | 140 | 593 | 156 | 1.2 | 1 | 5 | 62 | 272 | 168 | 3.2 | 2 | 26 | 10 | 157 | 47 | 1.5 | 1 | 4 | 3.2 | 106 | 48 | 1.8 | 1 | 8 | 1.3 | 62 | 47 | 2.9 | 2 | 16 | 0.4 | Are there any other things I can do to reduce the time to check criteria, and more importantly are there any ways for me to reduce the number of criteria checks required (for example, by pre-processing the input values), since there is such low selectivity?

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  • Problem using find function in Matlab

    - by Peter Etchells
    Hi all, I have two arrays of data that I'm trying to amalgamate. One contains actual latencies from an experiment in the first column (e.g. 0.345, 0.455... never more than 3 decimal places), along with other data from that experiment. The other contains what is effectively a 'look up' list of latencies ranging from 0.001 to 0.500 in 0.001 increments, along with other pieces of data. Both data sets are X-by-Y doubles. What I'm trying to do is something like... for i = 1:length(actual_latency) row = find(predicted_data(:,1) == actual_latency(i) full_set(i,1:4) = [actual_latency(i) other_info(i) predicted_info(row,2)... predicted_info(row,3)]; end ...in order to find the relevant row in predicted_data where the look up latency corresponds to the actual latency. I then use this to created an amalgamated data set, full_set. I figured this would be really simple, but the find function keeps failing by throwing up an empty matrix when looking for an actual latency that I know is in predicted_data(:,1) (as I've double-checked during debugging). Moreover, if I replace find with a for loop to do the same job, I get a similar error. It doesn't appear to be systematic - using different participant data sets throws it up in different places. Furthermore, during debugging mode, if I use find to try and find a hard-coded value of actual_latency, it doesn't always work. Sometimes yes, sometimes no. I'm really scratching my head over this, so if anyone has any ideas about what might be going on, I'd be really grateful.

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  • OpenType Font Parsing for Pleasure and Profit (anyone understand these damn tables?)

    - by mustISignUp
    So, this is mainly for fun, I'm poking around and trying to find my way inside a few fonts and i have a few questions i'd reeally appreciate some help on if anyone has done this kind of stuff. cmap table The fonts i am testing with contain several cmap subtables of different formats. I can read them, but i don't understand which i should be using. ie. what is the strategy for choosing the most appropriate subtable? Does this even make sense? glyf table This is really making my head hurt. I'm going by what is on here. Looking at the second table on that page.. I've got 'n' endPtsOfContours, 'n' instructions and 'n' flags but it is not clear to me if i have the same number of flags as contours (i know how many contours i have). Then, to make matters worse..(fun!) i have an array of xCoords and an array of yCoords. These arrays seem to be of indeterminate length and may contain data of either BYTE or SHORT but we are not going to tell you which.. Thanks to anyone willing to shed some light.

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  • Java servlet's request parameter's name set to entire json object

    - by Geren White
    I'm sending a json object through ajax to a java servlet. The json object is key-value type with three keys that point to arrays and a key that points to a single string. I build it in javascript like this: var jsonObject = {"arrayOne": arrayOne, "arrayTwo": arrayTwo, "arrayThree": arrThree, "string": stringVar}; I then send it to a java servlet using ajax as follows: httpRequest.open('POST', url, true); httpRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); httpRequest.setRequestHeader("Connection", "close"); var jsonString = jsonObject.toJSONString(); httpRequest.send(jsonString); This will send the string to my servlet, but It isn't showing as I expect it to. The whole json string gets set to the name of one of my request's parameters. So in my servlet if I do request.getParameterNames(); It will return an enumeration with one of the table entries' key's to be the entire object contents. I may be mistaken, but my thought was that it should set each key to a different parameter name. So I should have 4 parameters, arrayOne, arrayTwo, arrayThree, and string. Am I doing something wrong or is my thinking off here? Any help is appreciated. Thanks

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  • Array Intersect giving wrong output

    - by Pankaj Khurana
    Hi, I need to find common elements between two arrays. My code is: $sql="SELECT DISTINCT fk_paytbl_discounts_discountid as discountid from paytbl_discounts_students WHERE fk_vtiger_cf_601='".$categoryid."'"; $discountstudentinfo=$objdb->customQuery($sql,false); $sql1="SELECT DISTINCT fk_paytbl_discounts_discountid as discountid from paytbl_discounts_variants WHERE fk_vtiger_products_productid='".$variantid."'"; $discountvariantinfo=$objdb->customQuery($sql1,false); $commondiscount=array_intersect($discountvariantinfo,$discountstudentinfo); First array Array ( [0] => Array ( [discountid] => 2 ) [1] => Array ( [discountid] => 8 ) [2] => Array ( [discountid] => 5 ) [3] => Array ( [discountid] => 4 ) ) Second array Array ( [0] => Array ( [discountid] => 1 ) [1] => Array ( [discountid] => 5 ) ) Common array Array ( [0] => Array ( [discountid] => 1 ) [1] => Array ( [discountid] => 5 ) ) Common array should have only discountid 5 but its showing 1 also. Please help me on this Thanks

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  • Scan file contents into an array of a structure.

    - by ZaZu
    Hello, I have a structure in my program that contains a particular array. I want to scan a random file with numbers and put the contents into that array. This is my code : ( NOTE : This is a sample from a bigger program, so I need the structure and arrays as declared ) The contents of the file are basically : 5 4 3 2 5 3 4 2 #include<stdio.h> #define first 500 #define sec 500 struct trial{ int f; int r; float what[first][sec]; }; int trialtest(trial *test); main(){ trial test; trialtest(&test); } int trialtest(trial *test){ int z,x,i; FILE *fin; fin=fopen("randomfile.txt","r"); for(i=0;i<5;i++){ fscanf(fin,"%5.2f\t",(*test).what[z][x]); } fclose(fin); return 0; } But the problem is, whenever this I run this code, I get this error : (25) : warning 508 - Data of type 'double' supplied where a pointer is required I tried adding do{ for(i=0;i<5;i++){ q=fscanf(fin,"%5.2f\t",(*test).what[z][x]); } }while(q!=EOF); But that didnt work either, it gives the same error. Does anyone have a solution to this problem ?

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  • Using MPI_Type_Vector and MPI_Gather, in C.

    - by Goloneg
    Hi, I am trying to multiply square matrices in parallele with MPI. I use a MPI_Type_vector to send square submatrixes (arrays of float) to the processes, so they can calculate subproducts. Then, for the next iterations, these submatrices are send to neighbours processes as MPI_Type_contiguous (the whole submatrix is sent). This part is working as expected, and local results are corrects. Then, I use MPI_Gather with the contiguous types to send all local results back to the root process. The problem is, the final matrix is build (obviously, by this method) line by line instead of submatrix by submatrix. I wrote an ugly procedure rearranging the final matrix, but I would like to know if there is a direct way of performing the "inverse" operation of sending MPI_Type_vectors (i.e., sending an array of values and directly arranging it in a subarray form in the receiving array). An example, to try and clarify my long text : A[16] and B[16] are 4x4 matrices to be multiplied ; C[16] will contain the result ; 4 processes are used (Pi with i from 0 to 3) : Pi gets two 2x2 submatrices : subAi[4] and subBi[4] ; their product is stored locally in subCi[4]. For instance, P0 gets : subA0[4] containing A[0], A[1], A[4] and A[5] ; subB0[4] containing B[0], B[1], B[4] and B[5]. After everything is calculed, root process gathers all subCi[4]. Then C[16] contains : [ subC0[0], subC0[1], subC0[2], subC0[3], subC1[0], subC1[1], subC1[2], subC1[3], subC2[0], subC2[1], subC2[2], subC2[3], subC3[0], subC3[1], subC3[2], subC3[3]] and I would like it to be : [ subC0[0], subC0[1], subC1[0], subC1[1], subC0[2], subC0[3], subC1[2], subC1[3], subC2[0], subC2[1], subC3[0], subC3[1], subC2[2], subC2[3], subC3[2], subC3[3]] without further operation. Does someone know a way ? Thanks for your advices.

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  • Value types of variable size

    - by YellPika
    I'm trying to code a small math library in C#. I wanted to create a generic vector structure where the user could define the element type (int, long, float, double, etc.) and dimensions. My first attempt was something like this... public struct Vector<T> { public readonly int Dimensions; public readonly T[] Elements; // etc... } Unfortunately, Elements, being an array, is also a reference type. Thus, doing this, Vector<int> a = ...; Vector<int> b = a; a[0] = 1; b[0] = 2; would result in both a[0] and b[0] equaling 2. My second attempt was to define an interface IVector<T>, and then use Reflection.Emit to automatically generate the appropriate type at runtime. The resulting classes would look roughly like this: public struct Int32Vector3 : IVector<T> { public int Element0; public int Element1; public int Element2; public int Dimensions { get { return 3; } } // etc... } This seemed fine until I found out that interfaces seem to act like references to the underlying object. If I passed an IVector to a function, and changes to the elements in the function would be reflected in the original vector. What I think is my problem here is that I need to be able to create classes that have a user specified number of fields. I can't use arrays, and I can't use inheritance. Does anyone have a solution? EDIT: This library is going to be used in performance critical situations, so reference types are not an option.

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  • Filling in uninitialized array in java? (or workaround!)

    - by AlexRamallo
    Hello all, I'm currently in the process of creating an OBJ importer for an opengles android game. I'm relatively new to the language java, so I'm not exactly clear on a few things. I have an array which will hold the number of vertices in the model(along with a few other arrays as well): float vertices[]; The problem is that I don't know how many vertices there are in the model before I read the file using the inputstream given to me. Would I be able to fill it in as I need to like this?: vertices[95] = 5.004f; //vertices was defined like the example above or do I have to initialize it beforehand? if the latter is the case then what would be a good way to find out the number of vertices in the file? Once I read it using inputstreamreader.read() it goes to the next line until it reads the whole file. The only thing I can think of would be to read the whole file, count the number of vertices, then read it AGAIN the fill in the newly initialized array. Is there a way to dynamically allocate the data as is needed?

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  • STLifying C++ classes

    - by shambulator
    I'm trying to write a class which contains several std::vectors as data members, and provides a subset of vector's interface to access them: class Mesh { public: private: std::vector<Vector3> positions; std::vector<Vector3> normals; // Several other members along the same lines }; The main thing you can do with a mesh is add positions, normals and other stuff to it. In order to allow an STL-like way of accessing a Mesh (add from arrays, other containers, etc.), I'm toying with the idea of adding methods like this: public: template<class InIter> void AddNormals(InIter first, InIter last); Problem is, from what I understand of templates, these methods will have to be defined in the header file (seems to make sense; without a concrete iterator type, the compiler doesn't know how to generate object code for the obvious implementation of this method). Is this actually a problem? My gut reaction is not to go around sticking huge chunks of code in header files, but my C++ is a little rusty with not much STL experience outside toy examples, and I'm not sure what "acceptable" C++ coding practice is on this. Is there a better way to expose this functionality while retaining an STL-like generic programming flavour? One way would be something like this: (end list) class RestrictedVector<T> { public: RestrictedVector(std::vector<T> wrapped) : wrapped(wrapped) {} template <class InIter> void Add(InIter first, InIter last) { std::copy(first, last, std::back_insert_iterator(wrapped)); } private: std::vector<T> wrapped; }; and then expose instances of these on Mesh instead, but that's starting to reek a little of overengineering :P Any advice is greatly appreciated!

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  • jQuery $.each()-problem

    - by Volmar
    Hi, im making a wordpress plugin and i have a function where i import images, this is done with a $.each()-loop that calls a .load()-function every iteration. The load-function page the load-function calls is downloading the image and returns a number. The number is imported into a span-element. The source and destination Arrays is being imported from LI-elemnts of a hidden ULs. this way the user sees a counter counting from zero up to the total number of images being imported. You can se my jQuery code below: jQuery(document).ready(function($) { $('#mrc_imp_img').click(function(){ var dstA = []; var srcA = []; $("#mrc_dst li").each(function() { dstA.push($(this).text()) }); $("#mrc_src li").each(function() { srcA.push($(this).text()) }); $.each(srcA, function (i,v) { $('#mrc_imgimport span.fc').load('/wp-content/plugins/myplugin/imp.php?num='+i+'&dst='+dstA[i]+'&src='+srcA[i]); }); }); }); This works pretty good but sometimes it looks like the load function isn't updating the DOM as fast as it should because sometimes the numbers that the span is updated with is lower than the previous and almost everytime a lower number is replacing the last number in the end. How can i prevent this from happening and how can i make it hide '#mrc_imp_img' when the $.each-loop is ready?

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  • Correct way to initialize dynamic Array in C++

    - by mef
    Hey guys, I'm currently working on a C++ project, where dynamic arrays often appear. I was wondering, what could be the correct way to initialize a dynamic array using the new-operator? A colleague of mine told me that it's a no-no to use new within the constructor, since a constructor is a construct that shouldn't be prone to errors or shouldn't fail at all, respectively. Now let's consider the following example: We have two classes, a more or less complex class State and a class StateContainer, which should be self-explained. class State { private: unsigned smth; public: State(); State( unsigned s ); }; class StateContainer { private: unsigned long nStates; State *states; public: StateContainer(); StateContainer( unsigned long n ); virtual ~StateContainer(); }; StateContainer::StateContainer() { nStates = SOME_DEFINE_N_STATES; states = new State[nStates]; if ( !states ) { // Error handling } } StateContainer::StateContainer( unsigned long n ) { nStates = n; try { states = new State[nStates] } catch ( std::bad_alloc &e ) { // Error handling } } StateContainer::~StateContainer() { if ( states ) { delete[] states; states = 0; } } Now actually, I have two questions: 1.) Is it ok, to call new within a constructor, or is it better to create an extra init()-Method for the State-Array and why? 2.) Whats the best way to check if new succeeded: if (!ptr) std::cerr << "new failed." or try { /*new*/ } catch (std::bad_alloc) { /*handling*/ } 3.) Ok its three questions ;o) Under the hood, new does some sort of ptr = (Struct *)malloc(N*sizeof(Struct)); And then call the constructor, right?

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  • android nested lists

    - by Raogrimm
    i'm new to programming android and i have found some useful things for my app, but i can't seem to find how to make a list filled with an string array display a new list that is going to be populated with a string array. i would like to have the user choose an item from the top_menu list and from there go to the desired area and have that array appear. this is what i have so far: public class HelloListActivity extends ListActivity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); String[] top_menu = getResources().getStringArray(R.array.top_menu); setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, top_menu)); ListView lv = getListView(); lv.setTextFilterEnabled(true); lv.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> parent, View view, int position, long id) { ??? } }); } all my arrays are working fine, i just don't know how to repopulate a new list with the other array depending on the choice the user made. any help is greatly appreciated

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  • Need Explanation of couchdb reduce function

    - by Alan
    From http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views The couchdb reduce function is defined as function (key, values, rereduce) { return sum(values); } key will be an array whose elements are arrays of the form [key,id] values will be an array of the values emitted for the respective elements in keys i.e. reduce([ [key1,id1], [key2,id2], [key3,id3] ], [value1,value2,value3], false) I am having trouble understanding when/why the array of keys would contain different key values. If the array of keys does contain different key values, how would I deal with it? As an example, assume that my database contains movements between accounts of the form. {"amount":100, "CreditAccount":"account_number", "DebitAccount":"account_number"} I want a view that gives the balance of an account. My map function does: emit( doc.CreditAccount, doc.amount ) emit( doc.DebitAccount, -doc.amount ) My reduce function does: return sum(values); I seem to get the expected results, however I can't reconcile this with the possibility that my reduce function gets different key values. Is my reduce function supposed to group key values first? What kind of result would I return in that case?

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  • java class that simulates a simple database table

    - by ericso
    I have a collection of heterogenous data that I pull from a database table mtable. Then, for every unique value uv in column A, I compute a function of (SELECT * FROM mtable WHERE A=uv). Then I do the same for column B, and column C. There are rather a lot of unique values, so I don't want to hit the db repeatedly - I would rather have a class that replicates some of the functionality (most importantly some version of SELECT WHERE). Additionally, I would like to abstract the column names away from the class definition, if that makes any sense - the constructor should take a list of names as a parameter, and also, I suppose, a list of types (right now this is just a String[], which seems hacky). I'm getting the initial data from a RowSet. I've more or less done this by using a hashmap that maps Strings to lists/arrays of Objects, but I keep getting bogged down in comparisons and types, and am thinking that my current implementation really isn't as clean and clear as it could be. I'm pretty new to java, also, and am not sure if I'm not going down a completely incorrect path. Does anyone have any suggestions?

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