MAT_VARCREATE(3) BSD Library Functions Manual MAT_VARCREATE(3)NAMEMat_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 exmaple, 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 typi‐
cally 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,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,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,COMPRESSION_NONE);
Mat_VarFree(matvar);
}
Mat_Close(matfp);
return EXIT_SUCCESS;
}
SEE ALSOMat_VarCreateStruct(3), Mat_VarFree(3), Mat_VarWrite(3)BSD March 18, 2012 BSD
