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Problem with MexFunction and MexGetPr

Asked by Michael Negosanti on 14 Jul 2019
Latest activity Edited by James Tursa
on 15 Jul 2019
Good morning,
I can't solve the problem of assignment from incompatible pointer type for the x and y pointer. The error that develops in Matlab, could be caused by the wrong use of the mxGetPr function for the x and y matrix pointers, but I don't know how to proceed.
Someone could give me directions.
thank you.
void mexFunction( int nlhs, mxArray *plhs[],int nrhs, const mxArray*prhs[] )
{
double **x;
double *z;
double *p;
double **y;
int i = 2;
int j = 5;
plhs[0]= mxCreateDoubleMatrix((mwSize)i, (mwSize)j, mxREAL);
x = mxGetPr(prhs[0]);
z = mxGetPr(prhs[1]);
p =mxGetPr(prhs[2]);
y = mxGetPr(plhs[0]);
functionsum(y,x,z,p);
return;
}

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1 Answer

Answer by James Tursa
on 15 Jul 2019
Edited by James Tursa
on 15 Jul 2019
 Accepted Answer

Impossible to answer without seeing the code for the functionsum( ) function. Maybe you could post that? Maybe all you need to do is this (but this is just a guess w/o seeing your code):
double *x;
double *z;
double *p;
double *y;
What version of MATLAB are you using?
Btw, you don't need to explicitly cast the i and j arguments since C has automatic type promotion. This would suffice:
plhs[0]= mxCreateDoubleMatrix( i, j, mxREAL);

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