Closed bharswami closed 11 months ago
Could you be more specific please? To which code/test are you referring to?
In fortran code ssids.f90 subroutine: spral_ssids_factor_ptr32 The return variable cinform%NUM_NEG, after deeper function calls, stores the number of negative pivots. Just wanted confirmation that it is being computed correctly.
As far as we are aware yes.
What does the number of negative pivots actually refer to? Mathematically?
As the documentation states (see https://www.numerical.rl.ac.uk/spral/doc/latest/C/ssids.html):
int num_neg Number of negative eigenvalues of the matrix D after factorize phase.
i.e. the number of negative eigenvalues of D in the LDLT factorisation.
Can you please check if the number of negative pivots (NUM_NEG) is being computed correctly?