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MAT_VARCREATESTRUCT(3) Library Functions Manual MAT_VARCREATESTRUCT(3)

NAME

Mat_VarCreateStruct
Creates a structure variable.

SYNOPSIS

#include <matio.h>

matvar_t *
Mat_VarCreateStruct(const char *name, int rank, size_t *dims, const char **fields, unsigned nfields);

DESCRIPTION

The Mat_VarCreateStruct() function creates a structure variable named name that can be written to a MAT file.

RETURN VALUES

If the structure variable was successfully created, a pointer to the variable is returned. Otherwise NULL is returned. The structure variable pointer should be free'd when no longer needed using Mat_VarFree(). The names of the fields are copied in the function, and thus should be released after calling the function if necessary.

EXAMPLES

This example program opens a MAT file named by the first argument to the program, and writes a structure named a to the file.
#include "matio.h"

int
main(int argc, char **argv)
{
    mat_t    *matfp;
    matvar_t *matvar;
    matvar_t *field;
    const char *fields[2] = {"field1", "field2"};
    double       data1 = 1, data2 = 2;
    size_t       dims[2] = {1, 1};

    matfp = Mat_Open(argv[1], MAT_ACC_RDWR);
    if ( NULL == matfp ) {
        fprintf(stderr, "Error opening MAT file %s0, argv[1]);
        return EXIT_FAILURE;
    }

    dims[0] = 1; dims[1] = 1;
    matvar = Mat_VarCreateStruct("a", 2, dims, fields, 2);
    if ( NULL == matvar ) {
        Mat_Close(matfp);
        return EXIT_FAILURE;
    }

    field = Mat_VarCreate(NULL, MAT_C_DOUBLE, MAT_T_DOUBLE, 2, dims, &data1,
                MAT_F_DONT_COPY_DATA);
    Mat_VarSetStructFieldByName(matvar, "field1", 0, field);

    field = Mat_VarCreate(NULL, MAT_C_DOUBLE, MAT_T_DOUBLE, 2, dims, &data2,
                MAT_F_DONT_COPY_DATA);
    Mat_VarSetStructFieldByName(matvar, "field2", 0, field);

    Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_NONE);
    Mat_VarFree(matvar);

    Mat_Close(matfp);
    return EXIT_SUCCESS;
}

SEE ALSO

Mat_VarCreate(3), Mat_VarSetStructFieldByName(3)
September 12, 2019 Linux 4.19.0-17-amd64