Re: Saving matrices in octave binary format from f90

[David Bateman]

address@hidden wrote:

> Dear all,
> I would like to know if (and how) it is possible to save complex vectors and 
> complex matrices in octave binary format directly from fortran90.
> I use intel fortran compiler (waiting for the release of GCC4.0 and gfortran) 
> under Debian.
> Best
> regards
>
>
>
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Paul Laub sent a c code snippet to save in a matrix in the binary 
format. See the message

http://www.octave.org/mailing-lists/help-octave/2004/2623

In the following messages in the thread I explained the bits of this 
format he was uncertain of. See

http://www.octave.org/mailing-list/help-octave/205/2634

That is the four-bytes, FE FF FF FF that he was unsure of is the value 
-2 in little-endian, as the file is marked with the header "Octave-1-L". 
If he'd marked it with a "B" instead of an "L", the -2 would have to be 
in big-endan format. The absolute value of the -2 is the number of 
dimensions in the matrix, and the following values are the dimensions.

As for the other byte that Paul couldn't identify, it comes from the 
file data-conv.h that defines the data type used to save the values in 
the file. Paul's code forces them to be doubles, but in some cases they 
might be floats or integers, and flagged differently as specificed in 
data-conv.h

In any case Paul's message above will give you a good start on saving to 
a binary format.

Regards
David



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Octave is freely available under the terms of the GNU GPL.

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