How to protect MEX file from empty inputs

Question

Francesco 2013-10-21

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90993-how-to-protect-mex-file-from-empty-inputs

回答： dpb 2013-10-21

Hello,

I have a function of the form:

void nodal_connectivity(double *links, int maxconnections,
                        int size_rn, int size_links,
                        double *node_connectivity);
void mexFunction(int nlhs, mxArray *plhs[],
                 int nrhs, const mxArray *prhs[])
{
  double *links;
  double *node_connectivity;
  int maxconnections,size_rn,size_links;
    if (nrhs!=4) mexErrMsgTxt("4 inputs required: links and maxconnections, size_rn, size_links!");
    if (nlhs!=1) mexErrMsgTxt("Only one output given, node_connectivity");
    links=mxGetPr(prhs[0]);
    maxconnections=mxGetScalar(prhs[1]);
    size_rn=mxGetScalar(prhs[2]);
    size_links=mxGetScalar(prhs[3]);
    plhs[0]=mxCreateDoubleMatrix(size_rn*maxconnections,1,mxREAL);
    node_connectivity=mxGetPr(plhs[0]);
    nodal_connectivity(links,maxconnections,size_rn,size_links,node_connectivity);
}

When I call the function, I would like to protect Matlab if the "links" array is empty. This may occur in my Matlab program. I know that I can simply put a not(isempty(links)) condition prior to execution of the MEX file, but to make it a bit more robust (i.e. in case I forget), is there a test in mxFunction that tests for empty inputs and if so, exits with a given return value for example?

Thank you!

F