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  • convert Arabic numerical to English

    - by hamitay
    i am looking for a way to convert the Arabic numerical string "??????????" to an English numerical string "0123456789" Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click dim Anum as string ="??????????" dim Enum as string =get_egnlishNum(Anum) End Sub private function get_egnlishNum(byval _Anum as string) as string '' converting code end function

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  • Importing long numerical identifiers into Excel

    - by Niels Basjes
    I have some data in a database that uses ids that have the form of 16 digit numbers. In some situations i need to export the data in such a way that it can be manipulated in excel. So i export the data into a file and import it into excel. I've tried several file formats and I'm stuck. The problem I'm facing is that when reading a file into excel that has a cell that looks like a number then excel treats it as a number. The catch is that (as far as i can tell) all numerical values in excel are double precision floating point which have a precision of less than 16 digits. So my ids are changed: very often the last digit its changed to a 0. So far I've only been able to convince excel to keep the Id unchanged by breaking it myself: by adding a letter or symbol to the Id. This however means that in order to use the value again it must be "unbroken". Is there a way to create a file where i can specify that excel must treat the value as a text without changing the value? Or its there a way to let excel treat the value as a long (64bit integer)?

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  • Algorithm to generate numerical concept hierarchy

    - by Christophe Herreman
    I have a couple of numerical datasets that I need to create a concept hierarchy for. For now, I have been doing this manually by observing the data (and a corresponding linechart). Based on my intuition, I created some acceptable hierarchies. This seems like a task that can be automated. Does anyone know if there is an algorithm to generate a concept hierarchy for numerical data? To give an example, I have the following dataset: Bangladesh 521 Brazil 8295 Burma 446 China 3259 Congo 2952 Egypt 2162 Ethiopia 333 France 46037 Germany 44729 India 1017 Indonesia 2239 Iran 4600 Italy 38996 Japan 38457 Mexico 10200 Nigeria 1401 Pakistan 1022 Philippines 1845 Russia 11807 South Africa 5685 Thailand 4116 Turkey 10479 UK 43734 US 47440 Vietnam 1042 for which I created the following hierarchy: LOWEST ( < 1000) LOW (1000 - 2500) MEDIUM (2501 - 7500) HIGH (7501 - 30000) HIGHEST ( 30000)

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  • silverlight for .NET / CLR based numerical computing on osx

    - by Jonathan Shore
    I'm interested in using F# for numerical work, but my platforms are not windows based. Mono still has a significant performance penalty for programs that generate a significant amount of short-lived objects (as would be typical for functional languages). Silverlight is available on OSX. I had seen some reference indicating that assemblies compiled in the usual way could not be referenced, but not clear on the details. I'm not interested in UIs, but wondering whether could use the VM bundled with silverlight effectively for execution? I would want to be able to reference a large library of numerical models I already have in java (cross-compiled via IKVM to .NET assemblies) and a new codebase written in F#. My hope would be that the silverlight VM on OSX has good performance and can reference external assemblies and native libraries. Is this doable?

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  • Function lfit in numerical recipes, providing a test function

    - by Simon Walker
    Hi I am trying to fit collected data to a polynomial equation and I found the lfit function from Numerical Recipes. I only have access to the second edition, so am using that. I have read about the lfit function and its parameters, one of which is a function pointer, given in the documentation as void (*funcs)(float, float [], int)) with the help The user supplies a routine funcs(x,afunc,ma) that returns the ma basis functions evaluated at x = x in the array afunc[1..ma]. I am struggling to understand how this lfit function works. An example function I found is given below: void fpoly(float x, float p[], int np) /*Fitting routine for a polynomial of degree np-1, with coe?cients in the array p[1..np].*/ { int j; p[1]=1.0; for (j=2;j<=np;j++) p[j]=p[j-1]*x; } When I run through the source code for the lfit function in gdb I can see no reference to the funcs pointer. When I try and fit a simple data set with the function, I get the following error message. Numerical Recipes run-time error... gaussj: Singular Matrix ...now exiting to system... Clearly somehow a matrix is getting defined with all zeroes. I am going to involve this function fitting in a large loop so using another language is not really an option. Hence why I am planning on using C/C++. For reference, the test program is given here: int main() { float x[5] = {0., 0., 1., 2., 3.}; float y[5] = {0., 0., 1.2, 3.9, 7.5}; float sig[5] = {1., 1., 1., 1., 1.}; int ndat = 4; int ma = 4; /* parameters in equation */ float a[5] = {1, 1, 1, 0.1, 1.5}; int ia[5] = {1, 1, 1, 1, 1}; float **covar = matrix(1, ma, 1, ma); float chisq = 0; lfit(x,y,sig,ndat,a,ia,ma,covar,&chisq,fpoly); printf("%f\n", chisq); free_matrix(covar, 1, ma, 1, ma); return 0; } Also confusing the issue, all the Numerical Recipes functions are 1 array-indexed so if anyone has corrections to my array declarations let me know also! Cheers

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  • Return numerical array in python

    - by khan
    Okay..this is kind of an interesting question. I have a php form through which user enters values for x and y like this: X: [1,3,4] Y: [2,4,5] These values are stored into database as varchars. From there, these are called by a python program which is supposed to use them as numerical (numpy) arrays. However, these are called as plain strings, which means that calculation can not be performed over them. Is there a way to convert them into numerical arrays before processing or is there something else which is wrong? Helpp!!

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  • array_splice() - Numerical Offsets of Associative Arrays

    - by Alix Axel
    I'm trying to do something but I can't find any solution, I'm also having some trouble putting it into works so here is a sample code, maybe it'll be enough to demonstrate what I'm aiming for: $input = array ( 'who' => 'me', 'what' => 'car', 'more' => 'car', 'when' => 'today', ); Now, I want to use array_splice() to remove (and return) one element from the array: $spliced = key(array_splice($input, 2, 1)); // I'm only interested in the key... The above will remove and return 1 element (third argument) from $input (first argument), at offset 2 (second argument), so $spliced will hold the value more. I'll be iterating over $input with a foreach loop, I know the key to be spliced but the problem is I don't know its numerical offset and since array_splice only accepts integers I don't know what to do. A very dull example: $result = array(); foreach ($input as $key => $value) { if ($key == 'more') { // Remove the index "more" from $input and add it to $result. $result[] = key(array_splice($input, 2 /* How do I know its 2? */, 1)); } } I first though of using array_search() but it's pointless since it'll return the associative index.... How do I determine the numerical offset of a associative index?

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  • Reversible numerical calculations in Prolog

    - by user8472
    While reading SICP I came across logic programming chapter 4.4. Then I started looking into the Prolog programming language and tried to understand some simple assignments in Prolog. I found that Prolog seems to have troubles with numerical calculations. Here is the computation of a factorial in standard Prolog: f(0, 1). f(A, B) :- A > 0, C is A-1, f(C, D), B is A*D. The issues I find is that I need to introduce two auxiliary variables (C and D), a new syntax (is) and that the problem is non-reversible (i.e., f(5,X) works as expected, but f(X,120) does not). Naively, I expect that at the very least C is A-1, f(C, D) above may be replaced by f(A-1,D), but even that does not work. My question is: Why do I need to do this extra "stuff" in numerical calculations but not in other queries? I do understand (and SICP is quite clear about it) that in general information on "what to do" is insufficient to answer the question of "how to do it". So the declarative knowledge in (at least some) math problems is insufficient to actually solve these problems. But that begs the next question: How does this extra "stuff" in Prolog help me to restrict the formulation to just those problems where "what to do" is sufficient to answer "how to do it"?

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  • Numerical calculations in Prolog

    - by user8472
    While reading SICP I came across logic programming chapter 4.4. Then I started looking into the Prolog programming language and tried to understand some simple assignments in Prolog. I found that Prolog seems to have troubles with numerical calculations. Here is the computation of a factorial in standard Prolog: f(0, 1). f(A, B) :- A > 0, C is A-1, f(C, D), B is A*D. The issues I find is that I need to introduce two auxiliary variables (C and D), a new syntax (is) and that the problem is non-reversible (i.e., f(5,X) works as expected, but f(X,120) does not). Naively, I expect that at the very least C is A-1, f(C, D) above may be replaced by f(A-1,D), but even that does not work. My question is: Why do I need to do this extra "stuff" in numerical calculations but not in other queries? I do understand (and SICP is quite clear about it) that in general information on "what to do" is insufficient to answer the question of "how to do it". So the declarative knowledge in (at least some) math problems is insufficient to actually solve these problems. But that begs the next question: How does this extra "stuff" in Prolog help me to restrict the formulation to just those problems where "what to do" is sufficient to answer "how to do it"?

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  • How do I assign a number value to a non-numerical value in Excel

    - by Keyslinger
    Greetings I have an some survey responses with values like "VU" for "Very Unlikely" and "S" for Sometimes. Each survey response occupies a cell. For each cell containing a survey response, I want to fill another cell with a corresponding number. For example, for every cell containing "VU" I want to fill a corresponding cell with the number 1. How is this done?

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  • Excel Pivot Tables -- Divide Numerical Column Data into Ranges

    - by ktm5124
    Hi, I have an Excel spreadsheet with a column called "Time Elapsed" that stores the number of days it took to complete a task. I would like to make a pivot table out of this spreadsheet where I divide the "Time Elapsed" column into ranges, e.g., how many tasks took 0 to 4 days to complete how many tasks took 5 to 9 days how many took 10 to 14 days how many took 15+ days Do I have to create new columns in my spreadsheet dedicated to each interval (0 to 4, 5 to 9, etc.) or can I use some feature of pivot tables to separate my one "Time Elapsed" column into intervals? Thanks in advance.

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  • Access element in json having numerical index

    - by hunt
    i have following format of json in which i want to asscess 0.4 , kem , 2 , 2000 values but it seems it doesn't have name index so how one can access it in jquery. when i paste following code in json viewer then i am getting numerical index for 0.4 , kem , 2 "td": [ { "@attributes": { "class": "odd" }, "span": [ "3", "7" ] }, "0.4", "Kem", "24\/04\/2010", "2000", "2", "14000", "Good", "Buckley", "56.0", "2:05.32", "36.65", "54.5" ] }

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  • Java code optimization leads to numerical inaccuracies and errors

    - by rano
    I'm trying to implement a version of the Fuzzy C-Means algorithm in Java and I'm trying to do some optimization by computing just once everything that can be computed just once. This is an iterative algorithm and regarding the updating of a matrix, the clusters x pixels membership matrix U, this is the update rule I want to optimize: where the x are the element of a matrix X (pixels x features) and v belongs to the matrix V (clusters x features). And m is a parameter that ranges from 1.1 to infinity. The distance used is the euclidean norm. If I had to implement this formula in a banal way I'd do: for(int i = 0; i < X.length; i++) { int count = 0; for(int j = 0; j < V.length; j++) { double num = D[i][j]; double sumTerms = 0; for(int k = 0; k < V.length; k++) { double thisDistance = D[i][k]; sumTerms += Math.pow(num / thisDistance, (1.0 / (m - 1.0))); } U[i][j] = (float) (1f / sumTerms); } } In this way some optimization is already done, I precomputed all the possible squared distances between X and V and stored them in a matrix D but that is not enough, since I'm cycling througn the elements of V two times resulting in two nested loops. Looking at the formula the numerator of the fraction is independent of the sum so I can compute numerator and denominator independently and the denominator can be computed just once for each pixel. So I came to a solution like this: int nClusters = V.length; double exp = (1.0 / (m - 1.0)); for(int i = 0; i < X.length; i++) { int count = 0; for(int j = 0; j < nClusters; j++) { double distance = D[i][j]; double denominator = D[i][nClusters]; double numerator = Math.pow(distance, exp); U[i][j] = (float) (1f / (numerator * denominator)); } } Where I precomputed the denominator into an additional column of the matrix D while I was computing the distances: for (int i = 0; i < X.length; i++) { for (int j = 0; j < V.length; j++) { double sum = 0; for (int k = 0; k < nDims; k++) { final double d = X[i][k] - V[j][k]; sum += d * d; } D[i][j] = sum; D[i][B.length] += Math.pow(1 / D[i][j], exp); } } By doing so I encounter numerical differences between the 'banal' computation and the second one that leads to different numerical value in U (not in the first iterates but soon enough). I guess that the problem is that exponentiate very small numbers to high values (the elements of U can range from 0.0 to 1.0 and exp , for m = 1.1, is 10) leads to ver y small values, whereas by dividing the numerator and the denominator and THEN exponentiating the result seems to be better numerically. The problem is it involves much more operations. Am I doing something wrong? Is there a possible solution to get both the code optimized and numerically stable? Any suggestion or criticism will be appreciated.

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  • Math/numerical formula every computer programmer should know

    - by aaa
    This is a follow-up question to What should every programmer know and Is mathematics necessary. So the question is, as a computer programmer, what is the most important/useful mathematical or numerical formula that you use? By Formula I mean anything that involves less obvious manipulations, whenever binomial coefficients or bit hacks. I work with multidimensional arrays and various matrix representations. So for me most commonly used formulas are: A(i,j,k,..) = a[i + j*Dim0 + k*Dim0*Dim1 + ... to map indexes to one dimension ( which is basic address calculation which many people do not seem to know). And triangular number T(i) = (i*i + i)/2 which is related to binomial coefficients, used to calculate address in triangular matrixes and many other things. What is your workhorse formula that you think programmer should know?

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  • Confused about GNU `sort(1)` of a numerical sub field

    - by Chen Levy
    I wish to sort a space separated table, with the numerical value that found on the 2nd field. I can assume that the 2nd field is always fooN but the length of N is unknown: antiq. foo11 girls colleaguing foo2 Leinsdorf Cousy foo0 Montgomeryville bowlegged foo1 pollack Chevrier foo10 ill-conceived candlebomb foo3 seventieths autochthony foo101 re-enable beneficiate foo100 osteometric I read man sort(1) and played with all sort of options. On my system I found the line: sort -n -k2.5 table to work. My question is why? According to the man page: -k, --key=POS1[,POS2] start a key at POS1, end it at POS 2 (origin 1) ... POS is F[.C][OPTS], where F is the field number and C the characterposition in the field. OPTS is one or more single-letter ordering options, which override global ordering options for that key. If no key is given, use the entire line as the key. So why sort -n -k2.4 table don't work and sort -n -k.5 does?

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  • Does Len function only evaluate numerical results?

    - by Mel
    Why does the following code not output "Error" if the form is submitted with a blank field? Does Len only evaluate numerical values? <cfif NOT Len(Trim("Form.myField"))> <cfoutput>Error</cfoutput> </cfif> The following also does not evaluate as expected: <cfif Len(Trim("Form.myField")) IS 0> <cfoutput>Error</cfoutput> </cfif> HTML: <input type="text" name="myField" value="">

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  • Using an int as the numerical representation of a string in C#

    - by bluewall21
    I'm trying to use an integer as the numerical representation of a string, for example, storing "ABCD" as 0x41424344. However, when it comes to output, I've got to convert the integer back into 4 ASCII characters. Right now, I'm using bit shifts and masking, as follows: int value = 0x41424344; string s = new string ( new char [] { (char)(value >> 24), (char)(value >> 16 & 0xFF), (char)(value >> 8 & 0xFF), (char)(value & 0xFF) }); Is there a cleaner way to do this? I've tried various casts, but the compiler, as expected, complained about it.

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  • php: fopen() of an URL breaks for domain names, not for numerical addresses

    - by b0fh
    After hours of trying to debug a third-party application having trouble with fopen(), i finally discovered that php -r 'echo(file_get_contents("http://www.google.com/robots.txt"));' fails, but php -r 'echo(file_get_contents("http://173.194.32.81/robots.txt"));' Succeeds. Note that as the webserver user, I can ping www.google.com and it resolves just fine. I straced both executions of PHP, and they diverge like this: For the numerical v4 URL: socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 connect(3, {sa_family=AF_INET, sin_port=htons(80), sin_addr=inet_addr("173.194 poll([{fd=3, events=POLLOUT}], 1, 0) = 0 (Timeout) ...[bunch of poll/select/recvfrom]... close(3) = 0 For the domain name: socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP) = 3 close(3) = 0 PHP didn't even try to do anything with that socket, it seems. Or even resolve the domain, for that matter. WTF ? Recompiling PHP with or without ipv6 support did not seem to matter. Disabling ipv6 on this system is not desirable. Gentoo Linux, PHP 5.3.14, currently giving a try to PHP 5.4 and see if it helps. Anyone has an idea ? EDIT: php -r 'echo gethostbyname("www.google.com");' Works and yield an ipv4, while php -r 'echo(file_get_contents("http://[2a00:1450:4007:803::1011]/"));' Seems to return a blank result. EDIT 2: I didn't even notice the first time, that the v6 socket opened when the name is used is a SOCK_DGRAM.

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  • Algorithms for finding a numerical record in a list of ordered numbers

    - by Ankur
    I have a list of incomplete ordered numbers. I want to find a particular number with as few steps as possible. Are there any improvements on this algorithm, I assume you can count the set size without difficulty - it will be stored and updated every time a new item is added. Your object is to get your cursor over the value x The first number (smallest) is s, and the last number (greatest) is g. Take the midpoint m1 of the set: calculate is x < m1, If yes then s <= x < m1 If no then m1 < x <= g If m1 = x then you're done. Keep repeating till you find x. Basically dividing the set into two parts with each iteration till you hit x. The purpose is to retrieve a numerical id from a very large table to then find the associated other records. I would imagine this is the most trivial kind of indexing available, are there improvements?

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  • Convert a Dynamic[] construct to a numerical list

    - by Leo Alekseyev
    I have been trying to put together something that allows me to extract points from a ListPlot in order to use them in further computations. My current approach is to select points with a Locator[]. This works fine for displaying points, but I cannot figure out how to extract numerical values from a construct with head Dynamic[]. Below is a self-contained example. By dragging the gray locator, you should be able to select points (indicated by the pink locator and stored in q, a list of two elements). This is the second line below the plot. Now I would like to pass q[[2]] to a function, or perhaps simply display it. However, Mathematica treats q as a single entity with head Dynamic, and thus taking the second part is impossible (hence the error message). Can anyone shed light on how to convert q into a regular list? EuclideanDistanceMod[p1_List, p2_List, fac_: {1, 1}] /; Length[p1] == Length[p2] := Plus @@ (fac.MapThread[Abs[#1 - #2]^2 &, {p1, p2}]) // Sqrt; test1 = {{1.`, 6.340196001221532`}, {1.`, 13.78779876355869`}, {1.045`, 6.2634018978377295`}, {1.045`, 13.754947081416544`}, {1.09`, 6.178367702583522`}, {1.09`, 13.72055251752498`}, {1.135`, 1.8183153704413153`}, {1.135`, 6.082497198000075`}, {1.135`, 13.684582525399742`}, {1.18`, 1.6809452373465104`}, {1.18`, 5.971583107298081`}, {1.18`, 13.646996905469383`}, {1.225`, 1.9480537697339537`}, {1.225`, 5.838386922625636`}, {1.225`, 13.607746407088161`}, {1.27`, 2.1183174369679234`}, {1.27`, 5.669799095595362`}, {1.27`, 13.566771130126131`}, {1.315`, 2.2572975468163463`}, {1.315`, 5.444014254828522`}, {1.315`, 13.523998701347882`}, {1.36`, 2.380307009155079`}, {1.36`, 5.153024664297602`}, {1.36`, 13.479342200528283`}, {1.405`, 2.4941312539733285`}, {1.405`, 4.861423833512566`}, {1.405`, 13.432697814928654`}, {1.45`, 2.6028066447609426`}, {1.45`, 4.619367407525507`}, {1.45`, 13.383942212133244`}}; DynamicModule[{p = {1.2, 10}, q = {1.3, 11}}, q := Dynamic@ First@test1[[ Ordering[{#, EuclideanDistanceMod[p, #, {1, .1}]} & /@ test1, 1, #1[[2]] < #2[[2]] &]]]; Grid[{{Show[{ListPlot[test1, Frame -> True, ImageSize -> 300], Graphics@Locator[Dynamic[p]], Graphics@ Locator[q, Appearance -> {Small}, Background -> Pink]}]}, {Dynamic@p}, {q},{q[[2]]}}]]

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  • Retain numerical precision in an R data frame?

    - by David
    When I create a dataframe from numeric vectors, R seems to truncate the value below the precision that I require in my analysis: data.frame(x=0.99999996) returns 1 (see update 1) I am stuck when fitting spline(x,y) and two of the x values are set to 1 due to rounding while y changes. I could hack around this but I would prefer to use a standard solution if available. example Here is an example data set d <- data.frame(x = c(0.668732936336141, 0.95351462456867, 0.994620622127435, 0.999602102672081, 0.999987126195509, 0.999999955814133, 0.999999999999966), y = c(38.3026509783688, 11.5895099585560, 10.0443344234229, 9.86152339768516, 9.84461434575695, 9.81648333804257, 9.83306725758297)) The following solution works, but I would prefer something that is less subjective: plot(d$x, d$y, ylim=c(0,50)) lines(spline(d$x, d$y),col='grey') #bad fit lines(spline(d[-c(4:6),]$x, d[-c(4:6),]$y),col='red') #reasonable fit Update 1 Since posting this question, I realize that this will return 1 even though the data frame still contains the original value, e.g. > dput(data.frame(x=0.99999999996)) returns structure(list(x = 0.99999999996), .Names = "x", row.names = c(NA, -1L), class = "data.frame") Update 2 After using dput to post this example data set, and some pointers from Dirk, I can see that the problem is not in the truncation of the x values but the limits of the numerical errors in the model that I have used to calculate y. This justifies dropping a few of the equivalent data points (as in the example red line).

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