Returning a vector from C++ to matalb through mex?

HI, I am trying to return a vector back to matlab using the mex function. I declare a return pointer as, double *retPtr = NULL;

Then the return code is as follows: plhs[0] = mxCreateDoubleMatrix(N, 1, mxREAL); retPtr = mxGetPr(plhs[0]);

for (int i = 0; i < N; i++) { retPtr[i] = forest->predictLabel(&(testData[i*M]), M); }

The return type is a vector<int> , but I keep on getting the error: Error 1 error C2440: '=' : cannot convert from 'std::vector<_Ty>' to 'double'

I there a problem the way I declare the pointer. Any help would be appreciated.

Regards, Eric