NAME

       Mat_VarCreate — Creates a MAT variable structure.

SYNOPSIS

       #include <matio.h>

       matvar_t *
       Mat_VarCreate(const char *name,   enum matio_classes class_type,   enum matio_types data_type,  int rank,
           size_t *dims, void *data, int opt);

DESCRIPTION

       The Mat_VarCreate() function creates a MAT structure variable named name that can be  written  to  a  MAT
       file.   The class_type argument specifies the class of the variable, and the data_type argument specifies
       the type of the data.  For example, a double-precision class would use MAT_C_DOUBLE for  the  class  type
       and  MAT_T_DOUBLE for the data type.  In some instances, the data type may not match the class type.  For
       example, an array of integers can be written in the  double-precision  class  by  using  MAT_T_INT32  for
       data_type.

       The  rank  argument  specifies  how  many dimensions the data has.  The minimum rank is 2.  The number of
       elements in each dimension is specified in the array dims.

       The data argument is a pointer to the variable data.  The pointer is typically a  pointer  to  a  numeric
       array  (e.g.  double,  float,  int,  etc.)  for  real variables.  For complex variables, the pointer is a
       pointer to a mat_complex_split_t which contains pointers to the real and imaginary data as fields of  the
       structure.  For sparse variables, the pointer should be a mat_sparse_t *.

RETURN VALUES

       If  the  variable  was  successfully  created,  a pointer to the variable is returned.  Otherwise NULL is
       returned.  The variable should be free'd when no longer needed using Mat_VarFree().

EXAMPLES

       The example program below creates a MAT file named test.mat, and writes two real numeric variables x  and
       y and a complex variable z to the file.

       #include <stdlib.h>
       #include <stdio.h>
       #include "matio.h"

       int
       main(int argc,char **argv)
       {
           mat_t    *matfp;
           matvar_t *matvar;
           size_t    dims[2] = {10,1};
           double    x[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9,10},
                     y[10] = {11,12,13,14,15,16,17,18,19,20};
           struct mat_complex_split_t z = {x, y};

           matfp = Mat_CreateVer("test.mat", NULL, MAT_FT_DEFAULT);
           if ( NULL == matfp ) {
               fprintf(stderr, "Error creating MAT file
               return EXIT_FAILURE;
           }

           matvar = Mat_VarCreate("x", MAT_C_DOUBLE, MAT_T_DOUBLE, 2, dims, x, 0);
           if ( NULL == matvar ) {
               fprintf(stderr, "Error creating variable for 'x'0);
           } else {
               Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_NONE);
               Mat_VarFree(matvar);
           }

           matvar = Mat_VarCreate("y", MAT_C_DOUBLE, MAT_T_DOUBLE, 2, dims, y, 0);
           if ( NULL == matvar ) {
               fprintf(stderr, "Error creating variable for 'y'0);
           } else {
               Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_NONE);
               Mat_VarFree(matvar);
           }

           matvar = Mat_VarCreate("z", MAT_C_DOUBLE, MAT_T_DOUBLE, 2, dims, &z,
                        MAT_F_COMPLEX);
           if ( NULL == matvar ) {
               fprintf(stderr, "Error creating variable for 'z'0);
           } else {
               Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_NONE);
               Mat_VarFree(matvar);
           }

           Mat_Close(matfp);
           return EXIT_SUCCESS;
       }

SEE ALSO

       Mat_VarCreateStruct(3), Mat_VarFree(3), Mat_VarWrite(3)

Debian                                         September 12, 2019                               MAT_VARCREATE(3)