How to make two mxArray* scalar multiply each other?

Hi,

I have a simple step of multiplying two double scalar variables in mex. Why not the type "mxDouble" support multiply? Must I convert the mxDouble to double in c? My sample code is as below. I don't know much about the mx* type data. Thank you.

mxDouble* x = mxGetPr(prhs[0]);
mxDouble* y = mxGetPr(prhs[1]);
plhs[0] = mxCreateDoubleScalar (x*y);
 % expression must have arithmetic or unscoped enum type

Answer 1

[James Tursa]

x and y are pointers, so you need to dereference them to get at the double values they point to. So your code should be:

plhs[0] = mxCreateDoubleScalar (*x * *y);