Question

Hi I want to send a value from my matlab to my mex function. The value is generally about 10 digits long and i have used unsigned long long data type.

But i have difficulty accessing it from the mexfile.
mxGetPr returns double type, so is there some type conversion i have to do?

Answer 1

Yes, I just encountered this. You shouldn’t use mxGetPr anymore in general. The better way to do it is to first check the type like this:

if(!mxIsClass(prhs[0],"double"))
{
    mexErrMsgTxt("Data must be of type double!!!\n");
}

Then access the data through (double *)mxGetData(prhs[0]) or in your case (unsigned long long int*)mxGetData(prhs[0])

You can look up mxIsClass and mxGetData for more info.

Edit: Also here’s a list of the different types for mxIsClass