Re: Octave on windows - frequent crashes

[Benjamin Lindner]

> Also, gnuplot will always crash when I run "close all".

Yes this I also see sometimes, not always. I don't know what's
the cause of this, but it is an issue of gnuplot, not octave per se.
Octave also has a continuously evolving builtin plotting backend, based
on fltk. You can switch by executing
  backend("fltk");

> octave-3.2.3.exe:178:~\Desktop\literature review
> > cov(noise)
> error: memory exhausted or requested size too large for range of
> Octave's index type -- trying to return to prompt

Now this should not make you wonder why.
Octave/mingw32 is compiled as 32bit software.
You are trying to create a 40000x40000 matrix which would
require 4*4*10^8 * 4 bytes = 6.4*10^9 bytes (in single prec)
And this is simply not possible. Remember, it's a 32bit software.

You can easily generate this error by starting octave afresh
and try to execute
  t = zeros(40000,40000,"single");


> octave-3.2.3.exe:178:~\Desktop\literature review
> > whos
> Variables in the current scope:
>
>   Attr Name        Size                     Bytes  Class
>   ==== ====        ====                     =====  =====
>        argn        1x5                          5  char
>        n           1x1                          8  double
>    f   x         251x40000               40160000  single
>
> Total is 10040006 elements using 40160013 bytes

This now looks like a bug.
These are the variables local to the scope of the function that
was executed when the out-of-memory exception was thrown.
That can be simply reproduced by:
> foo = 1;
> a = zeros(251,40000);
> b = cov(a);
error: memory exhausted or requested size too large for range of 
Octave's index type -- trying to return to prompt
> whos
Variables in the current scope:

  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       argn        1x1                          1  char
       n           1x1                          8  double
   f   x         251x40000               80320000  double

Total is 10040002 elements using 80320009 bytes

This should be taken to octave's bug mailing list.

benjamin