From help-octave-request at bevo dot che dot wisc dot edu  Mon Jul 24 17:00:54 1995
Subject: Re: image command help?!
From: Ted dot Harding at nessie dot mcc dot ac dot uk (Ted Harding)
To: fcwang at ktaadn dot com (Feng Chi Wang)
Cc: help-octave at bevo dot che dot wisc dot edu
Date: Mon, 24 Jul 1995 22:36:16 +0200 (BST)

( Re Message From: Feng Chi Wang )
> If I have a simple 3x3 matrix called x, shouldn't I be able to
> get a grey scale image of it by simply doing a
> 
>     image (x)
> 
> ???
> 
> Actually I have a 512x512 matrix, but I couldn't get the 3x3 to
> plot. Either I get a Segmentation fault or 
> 
> warning: save: no such variable 'image.1627.img'
> octtopnm: unable to open input file

I think you have fallen foul of a typo in the file

          /usr/local/lib/octave/1.1.1/m/image/saveimage.m

as follows

          # Save image in octave image file format

          # The following line is buggy
          # eval (['save -asciii ', oct_file, ' map X']);
            eval (['save -ascii ', oct_file, ' map X']);

where oct_file is a string which is intended to be a filename of the form
"image.xxxx.img", where "xxxx" is four random digits. Because the flag
"-ascii" is mis-spelt, the save command executed is
          save -asciii image.xxxx.img map X
which tries to save variables 'image.xxxx.img', 'map' and 'X' to the file
'-asciii'. Hence the result.  If you make the correction given above, it
should work. (By the way, delete the file '-asciii' in your directory.)

Ted.                                    (Ted dot Harding at nessie dot mcc dot ac dot uk)