matthiasm@8: #include <stdio.h>
matthiasm@8: #include "mex.h"
matthiasm@8: 
matthiasm@8: /*
matthiasm@8: out = colop(M, v)
matthiasm@8: 
matthiasm@8: Apply binary operator to a vector v and to each column of M in turn
matthiasm@8: to produce a matrix the same size as M.
matthiasm@8: 
matthiasm@8: This is equivalent to
matthiasm@8: 
matthiasm@8: out = zeros(size(M));
matthiasm@8: for col=1:size(M,2)
matthiasm@8:   out(:,col) = op(M(:,col), v);
matthiasm@8: end
matthiasm@8: 
matthiasm@8: The code needs to be modified for each different operator 'op'.
matthiasm@8: eg op = '.*'
matthiasm@8: 
matthiasm@8: In vectorized form:
matthiasm@8: 
matthiasm@8: out = M .* repmat(v(:), 1, size(M,2))
matthiasm@8: 
matthiasm@8: (This function was formerly called repmat_and_mult.c)
matthiasm@8: 
matthiasm@8: */
matthiasm@8: 
matthiasm@8: /* M(i,j) = M(i + nrows*j) since Matlab uses Fortran layout. */
matthiasm@8: 
matthiasm@8:  
matthiasm@8: #define INMAT(i,j) M[(i)+nrows*(j)]
matthiasm@8: #define OUTMAT(i,j) out[(i)+nrows*(j)]
matthiasm@8: 
matthiasm@8: void mexFunction(
matthiasm@8:                  int nlhs,       mxArray *plhs[],
matthiasm@8:                  int nrhs, const mxArray *prhs[]
matthiasm@8: 		 )
matthiasm@8: {
matthiasm@8:   double *out, *M, *v;
matthiasm@8:   int nrows, ncols, r, c;
matthiasm@8:   
matthiasm@8:   /* read the input args */
matthiasm@8:   M = mxGetPr(prhs[0]);
matthiasm@8:   nrows = mxGetM(prhs[0]);
matthiasm@8:   ncols = mxGetN(prhs[0]);
matthiasm@8: 
matthiasm@8:   v = mxGetPr(prhs[1]);
matthiasm@8: 
matthiasm@8:   plhs[0] = mxCreateDoubleMatrix(nrows, ncols, mxREAL);
matthiasm@8:   out = mxGetPr(plhs[0]); 
matthiasm@8: 
matthiasm@8:   for (c=0; c < ncols; c++) {
matthiasm@8:     for (r=0; r < nrows; r++) {
matthiasm@8:       OUTMAT(r,c) = INMAT(r,c) * v[r]; 
matthiasm@8:       /* printf("r=%d, c=%d, M=%f, v=%f\n", r, c, INMAT(r,c), v[r]);  */
matthiasm@8:     }
matthiasm@8:   }
matthiasm@8: 
matthiasm@8: }
matthiasm@8: 
matthiasm@8: 
matthiasm@8: