[Octave-bug-tracker] [bug #53390] lu factorization of large sparse matrices often fails

[Marco Caliari]

Follow-up Comment #2, bug #53390 (project octave):

If you set


Control (UMFPACK_PRL) = 3;


before umfpack_report_*, you get some statistics. This one in case it works


Symbolic object: OK
Numeric object:  OK

column-form matrix, n_row 1000 n_col 1000, nz = 1253. OK

column-form matrix, n_row 1000 n_col 1000, nz = 800. OK

permutation vector, n = 1000. OK

permutation vector, n = 1000. OK

UMFPACK V5.6.2 (Apr 25, 2013), Info:
    matrix entry defined as:          double
    Int (generic integer) defined as: SuiteSparse_long
    BLAS library used: Fortran BLAS.  size of BLAS integer: 4
    MATLAB:                           no.
    CPU timer:                        POSIX C clock_getttime ( ) routine.
    number of rows in matrix A:       1000
    number of columns in matrix A:    1000
    entries in matrix A:              1000
    memory usage reported in:         16-byte Units
    size of int:                      4 bytes
    size of SuiteSparse_long:         8 bytes
    size of pointer:                  8 bytes
    size of numerical entry:          8 bytes
[skipped]


This one in case of failure


Symbolic object: OK
UMFPACK V5.6.2 (Apr 25, 2013): ERROR: pattern of matrix (Ap and/or Ai) has
changed

UMFPACK V5.6.2 (Apr 25, 2013), Info:
    matrix entry defined as:          double
    Int (generic integer) defined as: SuiteSparse_long
    BLAS library used: Fortran BLAS.  size of BLAS integer: 4
    MATLAB:                           no.
    CPU timer:                        POSIX C clock_getttime ( ) routine.
    number of rows in matrix A:       1000
    number of columns in matrix A:    1000
    entries in matrix A:              1000
    memory usage reported in:         16-byte Units
    size of int:                      4 bytes
    size of SuiteSparse_long:         8 bytes
    size of pointer:                  8 bytes
    size of numerical entry:          8 bytes
[skipped]


What do you think about the different sizes of SuiteSparse_long and int?

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