Can't read complex 64 bit ints with Octave?

[John Cognetti]

I modified the sample program from section 2.3.1, Writing numeric arrays, of the documentation to write int64_t (MAT_T_INT64) to a file. Upon reading the file from Octave, I get the error:

error: load: reading imaginary matrix data for 'z'

Is anyone else having this problem? Is this just a problem with Octave?

[tbeu]

Can you please attach the created MAT file and the modified sample code here. Thanks.

[tbeu]

Sorry, cannot reproduce.

[John Cognetti]

Sorry for the delay. Here's the source code, a screenshot of the error from Octave, and the mat file that was produced by the code.

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

int
main(int argc,char **argv)
{
    mat_t    *matfp;
    matvar_t *matvar;
    size_t    dims[2] = {10,1};
    int64_t   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 \"test.mat\"\n");
        return EXIT_FAILURE;
    }

    matvar = Mat_VarCreate("x",MAT_C_INT64,MAT_T_INT64,2,dims,x,0);
    if ( NULL == matvar ) {
        fprintf(stderr,"Error creating variable for 'x'\n");
    } else {
        Mat_VarWrite(matfp,matvar,MAT_COMPRESSION_NONE);
        Mat_VarFree(matvar);
    }

    matvar = Mat_VarCreate("y",MAT_C_INT64,MAT_T_INT64,2,dims,y,0);
    if ( NULL == matvar ) {
        fprintf(stderr,"Error creating variable for 'y'\n");
    } else {
        Mat_VarWrite(matfp,matvar,MAT_COMPRESSION_NONE);
        Mat_VarFree(matvar);
    }

    matvar = Mat_VarCreate("z",MAT_C_INT64,MAT_T_INT64,2,dims,&z,
                 MAT_F_COMPLEX);
    if ( NULL == matvar ) {
        fprintf(stderr,"Error creating variable for 'z'\n");
    } else {
        Mat_VarWrite(matfp,matvar,MAT_COMPRESSION_NONE);
        Mat_VarFree(matvar);
    }

    Mat_Close(matfp);
    return EXIT_SUCCESS;
}

[tbeu]

Well, test.mat is a valid v5 MAT file that both MATLAB and matio/matdump 1.5.8 are able to load/read. I am afraid you need to ask Octave developers why it cannot be read. It is likely that Octave links to an outdated libmatio which could not read such complex int64 arrays.

[John Cognetti]

Will do, thanks for the help. :-)

[tbeu]

Any news from the Octave team?