From help-octave-request at bevo dot che dot wisc dot edu Mon Jan 20 00:05:48 2003
Subject: Saving variable of type 'file'
From: "Dmitri A. Sergatskov" <dima at coffee dot phys dot unm dot edu>
To: help-octave at bevo dot che dot wisc dot edu
Date: Sun, 19 Jan 2003 22:59:39 -0700 (MST)

Apparently octave does not like saving variables of type 'file'.
I think it is a feature (one shall not have a valid fid if 
actual file has not been opened), but I also think that the way octave
handles it is at least confusing (mostly for 'save -binary'). Here is an 
example:

GNU Octave, version 2.1.42 (i686-pc-linux-gnu).
...
octave:1> fid=fopen('00README')
fid =
{
  id = 3
  name = 00README
  mode = r
  arch = native
  status = open
}
octave:2> t=(1:100);
octave:3> x=sin(t);
octave:4> save -binary test222.bin
warning: save: wrong type argument `file'
octave:5> save -ascii test222.txt
warning: save: wrong type argument `file'
octave:6> save -hdf5 test222.txt
warning: save: wrong type argument `file'
error: save: error while writing `fid' to hdf5 file
octave:6> whos

*** local user variables:

prot  type                       rows   cols  name
====  ====                       ====   ====  ====
 rwd  file                          -      -  fid
 rwd  range                         1    100  t
 rwd  matrix                        1    100  x

octave:7> quit
---
Now if I try to load files back, ascii and hdf5 work fine, but
binary gives an error message (though it does appear to load other 
variables correctly):

octave:1> load test222.txt
octave:2> whos

*** local user variables:

prot  type                       rows   cols  name
====  ====                       ====   ====  ====
 rwd  range                         1    100  t
 rwd  matrix                        1    100  x

octave:3> clear *
octave:4> whos
octave:5> load test222.bin
error: load: trouble reading binary file `test222.bin'
octave:5> whos

*** local user variables:

prot  type                       rows   cols  name
====  ====                       ====   ====  ====
 rwd  range                         1    100  t
 rwd  matrix                        1    100  x

----------------------------------------------------

What troubles me is the fact that it gives me an error message
that binary file is corrupted. Though in this example I can
verify that t and x is what expected, I do not know if it is
true in general case. 

Sincerely,

Dmitri. 




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