save and load bug.

[GARY FORBIS]

> Date: Sun, 28 Dec 2008 18:55:56 +0100> From: highegg at gmail.com> To: forbisgaryg at msn.com> Subject: Re: save and load bug.> CC: dbateman at dbateman.org; soren at hauberg.org; help at octave.org> > On Sun, Dec 28, 2008 at 6:09 PM, GARY FORBIS <forbisgaryg at msn.com> wrote:> > Thanks all. Eliminating one issue lets me focus better.> >> > I'm still looking. I'm very new to Octave even though I tried> > loading it in the spring of 2008. I didn't get as far as I've gotten now> > when> > trying to run the software I was using to learn more about ANNs and MathLab> > at the same time. I gave up quickly.> >> > I don't understand the structure of the files on sourceforge.> > I'm having a bit of trouble getting started. It's one more thing to learn.> > I saved octave-forge-bundle-20080831.tar.gz to my cygwin home directory,> > unzipped,> > and untarred it. It looks like the various pieces are tarred and zipped> > inside the package.> >> > I guess I can just recursively unzip an untar the files. Is there some> > documentation about> > where things are in the source files?> >> > I'm confused; maybe we both are. What are you trying to do? 
 
I'm trying to run a program written in mathlab that won't run on 
my computer under Octave.  I tracked down the problem to load not
working with a file produced by a save.  I discovered that Octave
uses an ascii file to do the save and I tracked down the minimum 
file that would fail.  I found the scalar that was in the last position
in the matrix that failed.  I wrote a simple program that kept adding
instances of that scalar to an array until the load of the array failed.
I created another program that only did two saves and two load to 
demonstrate that on my machine Octave 3.0.3 loaded with the windows
installer failed predictably.  I can find other numbers that will fail predictable
after different occurrances and as far as I can tell there's nothing remarkable
about the numbers or the number of occurrances of any of the characters
or digits in the record. 
 
> You can> get the latest stable Octave sources from> ftp://ftp.gnu.org/pub/gnu/octave/ or one of the GNU mirrors.> ftp.octave.org should also still work. I guess that building them on> Cygwin should be as simple as unpacking and doing configure&make,> provided you have the prerequisities.> If you have problems with compiling OctaveForge packages, you should> probably report the issue on the OctaveForge mailing list.
I don't particularly want to compile Octave.  I want to track down the  problem
and propose a solution.  Since other installations do not produce this problem, 
it looks like I'll have to dig deep enough into the code to see what limits exist.
I found dmlread earlier.  I'm assuming load uses a similar algorithm.  I was right
about reading a records at a time:
 
      while (getline (file, line))
 
While this sets an upper limit on the size of a record in characters it's much 
bigger than where I am encountering a problem.
> > My first guess was that the file was read a record at a time then parsed and> > I had hit a> > 16 bit limit. This didn't make much sense to me so I tried positive numbers> > and I was able> > to write records with many more numbers in them and load them back in.> > Negative number> > with few significant digits had less poblems as well.> >> > It's hard to tell what can cause your problem, especially as nobody> seems to be able to reproduce it. So, if you wish it to be> investigated further, you need to carry out more experiments and tell> us the results.
Well, as I said the small program works find on the cygwin octave 
version 3.0.2 so the problem is specific to the windows version 3.0.3
dated  (2008-11-22 11:55) 
 
It isn't a problem with 3.1.50 either so I'll just us that until I find some other problem
I have to deal with.
> regards> > -- > RNDr. Jaroslav Hajek> computing expert> Aeronautical Research and Test Institute (VZLU)> Prague, Czech Republic> url: www.highegg.matfyz.cz
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www-old.cae.wisc.edu/pipermail/help-octave/attachments/20081228/8bd9c246/attachment.html