Re: how to save matrix from an oct file

[Carlo de Falco]

On 11 May 2010, at 12:54, Carlo de Falco wrote:

> Hi,
> for debugging an oct file I am working on, I would like to save a  
> SparseMatrix to a file so that I can later load it in octave and  
> inspect it.
>
> I naively tried the following:
>
> 1) for ascii format
>
> SparseMatrix mat;
>
> ....
>
> std::ofstream os ("mat.txt");
> octave_value (mat).save_ascii (os);
> os.close();
>
> which seems to work but saves the matrix entries in IJV format and I  
> have to later convert them with spconvert.
>
> 2) for binary format
>
> std::ofstream os ("mat.mat");
> bool boolvar(false);
> octave_value (mat).save_binary (os, boolvar);
> os.close();
>
> which doesn't seem to work correctly as
>
> >> load mat.mat
> error: load: mat.mat: inconsistent number of columns near line 2
> error: load: unable to extract matrix size from file `mat.mat'
>
> What is the correct way to do this?
> Thanks in advance,
> c.


To (partly) respond to my own question, the following seems to work in  
3.2.3:

#include <octave/ls-oct-ascii.h>
SparseMatrix mat;
...
std::ofstream os ("mat.mat");
bool boolvar(false);
save_ascii_data (os, octave_value (mat),
                 std::string("mat"),
                 boolvar, boolvar);
os.close();

But the equivalent for binary format still fails:

#include <octave/ls-oct-binary.h>
SparseMatrix mat;
...
std::ofstream os ("mat.mat");
bool boolvar(false);
save_binary_data (os, octave_value (mat),
                  std::string("mat"), std::string(""),
                  boolvar, boolvar);
os.close();

>> load mat.mat
error: load: mat.mat: inconsistent number of columns near line 2
error: load: unable to extract matrix size from file `mat.mat'