MATLAB: MexSet for accessing CData

Question

I'm trying to plot data out from a MEX file (C language). To do this fast, I would like to use what corresponds to the following Matlab code:

 figure; imagehandle = imagesc(rand(500));
new_CData = rand(500);
set(newCData,imagehandle);

For this, the command mexSet() should be working. Ideally, I want something like this

mex plotX.c
figure; imagehandle = imagesc(rand(500)); 
A = rand(500);
plotX(A,imagehandle)

with a mex-Function plotX. Here is my tryout:

 #include "mex.h"
 void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
 {
    double *x, imagehandle;
    (void) plhs;
    x = mxGetPr(prhs[0]);
    imagehandle = mxGetScalar(prhs[1]);
    mexSet(imagehandle,"Cdata",x);
 }

This can be compiled, but I get the following error: "Error using plotX. Numeric or logical matrix required for image CData".

What am I doing wrong? I've asked the same question at Stackoverflow, but got no answer.

Best, Peter

Answer 1

Using another compiler (under Linux) made me aware of more details of the problem, and I could solve it like this:

 #include "mex.h"
 void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
 {
    double imagehandle;
    (void) plhs;
    imagehandle = mxGetScalar(prhs[1]);
    mexSet(imagehandle,"Cdata",prhs[0]);
 }

Seems so easy now ...