Octave Error: SparseMatrix::solve numeric factorization failed

Question

I have a large equation system to solve. The coefficients are stored in a sparse matrix CM of the dimension 320001 x 320001 elements, of which 18536032 are non-zero. The result vector B is 320001 elements long.

When executing

I=CM\\B

Octave Error: SparseMatrix::solve numeric factorization failed

I get the above error message. A brief look into the source code did not give me a clue.

Does anyone know what is causing that error?

BTW: when solving the same problem with a smaller matrix (eg 180001x180001) the program runs fine.

Johannes

Answer 1

Octave uses UMFPACK library to solve sparse linear systems. Inspecting the source shows that the error message is due to an error status with a negative value. List of error codes can be found in the user's guide . One of them is related to lack of enough memory:

UMFPACK ERROR out of memory, (-1): Not enough memory. The ANSI C malloc or realloc routine failed.