The MATLAB documentation for nchoosek says. P = perms(v) returns a matrix containing all permutations of the elements of vector v in reverse lexicographic order.Each row of P contains a different permutation of the n elements in v.Matrix P has the same data type as v, and it has n! '; toc; %' Elapsed time is 12.523955 seconds. C = nchoosek(v,k) is only practical for situations where length(v) is less than about 15. rows and n columns. 1. C = nchoosek(n,k) C = nchoosek(v,k) Description. No. nchoosek(1:100,10) is absolutely vast, far bigger than any typical machine could hold in memory. C = nchoosek(v,k) returns a matrix containing all possible combinations of the elements of vector v taken k at a time. I was kind of surprised, until I looked at the code for NCHOOSEK (by typing type nchoosek in the MATLAB command window). How can I apply this function to all the rows of the matrix or at least, for the above vector. Matrix C has k columns and n!/(k! (n - k)!) When you post the code you want to apply, more detailed suggestions are possible. And why does the variable a appear in the first and second input? Nchoosek is not written in any way to allow you to choose only some reduced subset. Therefore the readers cannot guess, what you expect as output. rows, where n is length(v).In this syntax, k must be a nonnegative integer. The most Matlab commands can handle a matrix input and process the operations for the subvectors automatically. In addition the meaning of 0 is unclear: Choose 0 elements from the vector a? nchoosek accepts scalar variables as 2nd input only. The second input, k, cannot have type int64 or uint64. C = nchoosek(v,k), where v is a row vector of length n, creates a matrix whose rows consist of all possible combinations of the elements of v taken at a time. Matrix C has k columns and n!/(k! rows, where n is length(v).In this syntax, k must be a nonnegative integer. When you want to access the contents of a cell, use the curly braces: A{1} etc. Or you can download the pre-compiled files and install the required runtime libraries of MSVC 2008. I want to use nchoosek function to find the combinations of (total number of 1's in a row) -1. I've tried this with perms,nchoosek,repelem,repmat,for-loops,unique,matrix concatenations,everything but i couldn't be able to find and algorithm. Octave and Matlab âwatâ matrix/vector inconsistencies. >> tic; pairs = nchoosek(1:N,2). When the first input, x, is a vector, nchoosek treats it as a set. You're not really going to be able to do this. C = nchoosek(v,k) returns a matrix containing all possible combinations of the elements of vector v taken k at a time. Searching the FEX is always a good idea. There you find FEX: VChooseK.mex.I think, this is the fastest implementation, but it needs a compilation. (n - k)!) 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