1. 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. 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! I want to use nchoosek function to find the combinations of (total number of 1's in a row) -1. This is the number of combinations of things taken at a time. (n - k)!) Learn more about nchoosek, combinations, vector The MATLAB documentation for nchoosek says. Matrix C has k columns and n!/(k! Octave and Matlab “wat” matrix/vector inconsistencies. In this case, x can have type int64 or uint64. Searching the FEX is always a good idea. (n - k)!) There you find FEX: VChooseK.mex.I think, this is the fastest implementation, but it needs a compilation. rows and n columns. Here, n= 3, k=n-1=2 (always k=n-1). When you want to access the contents of a cell, use the curly braces: A{1} etc. >> tic; pairs = nchoosek(1:N,2). Or you can download the pre-compiled files and install the required runtime libraries of MSVC 2008. In addition the meaning of 0 is unclear: Choose 0 elements from the vector a? C = nchoosek(v,k) is only practical for situations where length(v) is less than about 15. rows, where n is length(v).In this syntax, k must be a nonnegative integer. 2. nchoosek(1:100,10) is absolutely vast, far bigger than any typical machine could hold in memory. matlab matrix vector. C = nchoosek(n,k) C = nchoosek(v,k) Description. When you post the code you want to apply, more detailed suggestions are possible. C = nchoosek(v,k) returns a matrix containing all possible combinations of the elements of vector v taken k at a time. Matrix C has k columns and n!/(k! You're not really going to be able to do this. And why does the variable a appear in the first and second input? nchoosek accepts scalar variables as 2nd input only. No. C = nchoosek(v,k) returns a matrix containing all possible combinations of the elements of vector v taken k at a time. See Variable-Sizing Restrictions for Code Generation of Toolbox Functions (MATLAB Coder). C = nchoosek(n,k) where n and k are nonnegative integers, returns . 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. The most Matlab commands can handle a matrix input and process the operations for the subvectors automatically. 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. In fact, the set of 200 bit binary numbers has a HUGE number of subsets with 5 bits set. nchoosek help. 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