/* *  writemat.c - Create a binary MAT file. * *  Mastering MATLAB 7 C MAT-file Example 1 * */#include "mat.h"int makemat(const char *filename,             double *data, int m, int n,             char *mmstr) {  MATFile *mfile;  mxArray *mdata, *mstr;    /* Open the MAT file for writing. */  mfile = matOpen(filename, "w");  if (mfile == NULL) {    printf("Cannot open %s for writing.\n", filename);    return(EXIT_FAILURE);  }  /* Create the mxArray to hold the numeric data.     */  /* Note that the array dimensions are reversed.     */  /* C uses row order while MATLAB uses column order. */  /* The data array will be transposed in MATLAB.     */  mdata = mxCreateDoubleMatrix(n,m,mxREAL);  /* Copy the data to the mxArray. Note that mxGetData is */  /* similar to mxGetPr in that it returns a void pointer */  /* while mxGetPr returns a pointer to a double.         */  memcpy((void *)(mxGetData(mdata)), (void *)data,                   m*n*sizeof(double));    /* Create the string array. */  mstr = mxCreateString(mmstr);  /* Write the mxArrays to the MAT file. */  matPutVariable(mfile, "mydata", mdata);  matPutVariable(mfile, "mystr", mstr);  /* Free the mxArray memory. */  mxDestroyArray(mdata);  mxDestroyArray(mstr);  /* Close the MAT file. */  if (matClose(mfile) != 0) {    printf("Cannot close %s.\n",filename);    return(EXIT_FAILURE);  }    return(EXIT_SUCCESS);}int main(){   int status;  char *mmstr = "Mastering MATLAB Rocks!";  double data[3][4] = {{  1.0,  2.0,  3.0,  4.0 },                       {  5.5,  6.6,  7.7,  8.8 },                       { -4.0, -3.0, -2.0, -1.0 }};   status = makemat("mmtest.mat", *data, 3, 4, mmstr);  return(status);}