Mex transferring a vector from C ++ to matlab from a mex function

I am trying to speed up my Matlab program by writing several functions in C ++ and using the mex interface to integrate them. I got my results in a vector in C ++. I want to pass it to an array in MATLAB. I know that I have to redirect

 plhs[0] to the vector 

but i am not getting how exactly should I do it.

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1 answer

When I did things like this, I manually sorted the data so that it doesn't get freed when the C ++ procedure ends. Here's a basic plan:

#include <vector>
#include "mex.h"

mxArray * getMexArray(const std::vector<double>& v){
    mxArray * mx = mxCreateDoubleMatrix(1,v.size(), mxREAL);
    std::copy(v.begin(), v.end(), mxGetPr(mx));
    return mx;

void mexFunction(int nlhs, mxArray *plhs[ ], int nrhs, const mxArray *prhs[ ]) {
    std::vector<double> v;


    plhs[0] = getMexArray(v);



If I save this as test.cpp

and then open matlab in that directory, I do the following:

>> mex test.cpp
>> test

ans =

      0     1     2     3


which is the expected output. Hopefully this is a good starting point - you might want to embed it, but I'm not sure about that. Btw, if you haven't checked out the help on using matlab mex this is a great resource.