Hello,
I am trying to call mex function in other mex functions as below.
I need matrix multiplication but I realized I have to define it before I use it inside mexfunction.
Define 'matrixmultiplication.c' first and then use matrix multiplication inside 'calculation.c'
But I don't think this works.
Is there anyway I can call mexfunction in other mex functions? Or should I make a joint mex function of these two?
Any help would be appreciated
Thanks in advance
1. matrixmultiplication.c (I just downloaded from Matlab example file)
#if !defined(_WIN32)
#define dgemm dgemm_
#endif
#include "mex.h"
#include "blas.h"
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
double *A, *B, *C; /* pointers to input & output matrices*/
size_t m,n,p; /* matrix dimensions */
/* form of op(A) & op(B) to use in matrix multiplication */
char *chn = "N";
/* scalar values to use in dgemm */
double one = 1.0, zero = 0.0;
A = mxGetPr(prhs[0]); /* first input matrix */
B = mxGetPr(prhs[1]); /* second input matrix */
/* dimensions of input matrices */
m = mxGetM(prhs[0]);
p = mxGetN(prhs[0]);
n = mxGetN(prhs[1]);
if (p != mxGetM(prhs[1])) {
mexErrMsgIdAndTxt("MATLAB:matrixMultiply:matchdims",
"Inner dimensions of matrix multiply do not match.");
}
/* create output matrix C */
plhs[0] = mxCreateDoubleMatrix(m, n, mxREAL);
C = mxGetPr(plhs[0]);
/* Pass arguments to Fortran by reference */
dgemm(chn, chn, &m, &n, &p, &one, A, &m, B, &p, &zero, C, &m);
}
2. calculation.c (Version for practice)
#if !defined(_WIN32)
#define dgemm dgemm_
#endif
#include "mex.h"
#include "blas.h"
void secondfn(double *As, double *Bs, int m, int n, int p, double *Ds, double *Ps){
Ds = matrixmultiplication(As,Bs); // HERE I USED matrixmultiplication.c !!!!!!!
for (size_t i = 0; i < m*n; i++){
Ps[i] = Ds[i];
}
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
double *A, *B, *D, *P; /* pointers to input & output matrices*/
size_t m,n,p; /* matrix dimensions */
A = mxGetPr(prhs[0]); /* first input matrix */
B = mxGetPr(prhs[1]); /* second input matrix */
m = mxGetM(prhs[0]); /* dimensions of input matrices */
p = mxGetN(prhs[0]);
n = mxGetN(prhs[1]);
plhs[0] = mxCreateDoubleMatrix(m, n, mxREAL);
P = mxGetPr(plhs[0]);
D = (double *) mxMalloc(m*n*sizeof(*D));
secondfn(A, B, m, n, p, D, P);
mxFree(D);
}
mex matrixmultiplication.c calculation.c -lmwblas
