Anton - look closely at the function signature, and in particular the last input parameter
const mxArray * prhs[]
So prhs is an array of pointers to mxArray types. So trying
mexPrintf("%d \n", prhs[0]);
will write out the address of the mxArray that the first pointer in the array is pointing to.
If you want to access the values, then you could do something like the following, assuming that the first input parameter is a double
#include "mex.h"
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
double* A = 0;
size_t m = 0;
size_t n = 0;
int u = 0;
int v = 0;
// initialize the double pointer
A = mxGetPr(prhs[0]);
// get the dimensions of the first parameter
m = mxGetM(prhs[0]);
n = mxGetN(prhs[0]);
// write out the input
for (u=0;u<m;++u)
{
for (v=0;v<n;++v)
{
mexPrintf("%f ", A[u + v*m]);
}
mexPrintf("\n");
}
}
The above code assumes just one input parameter, which could be a scalar, array, or matrix, of type double. The A pointer is initialized with the address of the first element of the input (double) data via the mxGetPr function. We determine the dimension of this input, obtaining the number of rows with mxGetM, and the number of columns with mxGetN. We then write out the data.
Save the above function in a file named writeInput.c and compile as
mex writeInput.c
Test with the following examples
writeInput(1)
writeInput(1:4)
writeInput((1:4)')
writeInput(eye(4))
writeInput(eye(3,4))
writeInput(magic(6))
Using the above as a guide, it is relatively easy to handle multiple inputs of different data types.
EDIT
Changed above code so that it could compile with 'lcc-win32', 'Microsoft Windows SDK 7.1 (C)' and 'Xcode with Clang'. The difference is that all local variables must be declared together at the start of the function, rather than declaring (for example) the looping integers in the for block.
