Fwd: out of memory or dimension too large for Octave's index type

[Nicholas Jankowski]

(please reply all to keep the help list and everyone else in the conversation)

---------- Forwarded message ---------
From: Jiang, Yanda [E CPE] <yandaj@iastate.edu>
Date: Wed, Oct 26, 2022 at 12:30 PM
Subject: Re: out of memory or dimension too large for Octave's index type
To: Nicholas Jankowski <jankowski.nicholas@gmail.com>

On Wed, Oct 26, 2022, 12:02 Jiang, Yanda [E CPE] <yandaj@iastate.edu> wrote:

Yes, I tried this method and it got resolved.

Btw, may I check another issue, Nick?

Which method? There were two proposed which is why in asked again.

This method. 

  if (any (isinf (A(:))) || any (isnan(A(:))))

    error ("glpk: The values in A must be finite");

  endif

If the sentence below gave me the previous error message, does that mean the problem is not caused by index type, but out of memory? Kindly let me know your thoughts.

debug> size(Bf(:, noref))

ans =

   84450   67518

debug> size(Bbus(noslack, noref))

ans =

   67518   67518

Assuming Bf and Bbus are themselves not sparse arrays, then yes, it appears to be an out of memory problem. If they are 8 byte data types, then 

Bf = 84450 x 67518 =5.7e elements x 8 bytes = 46.5e9 bytes = 42.5GB

Bbus = 67518 x 67518 = 4.5e9 elements x 8 bytes = 36.5e9bytes = 34GB 

Bf and Bbus are sparse. But I guess the inverse of Bbus is not sparse anymore. Will it be different?

And is this an Octave problem or computer problem?