Hello PETSc users, I am currently trying to build a 1-D Schrodinger solver. I have built my hamiltonian matrix (of size 121 x 121) and i'm trying to find the eigenvalues. I have the following lines of code for the solver:
*call EPSCreate(PETSC_COMM_WORLD,eps,ierr)* *call EPSSetOperators(eps,ham,S,ierr)call EPSSetProblemType(eps,EPS_GHEP,ierr)* *call EPSSetFromOptions(eps,ierr)call EPSSetDimensions(eps,10,PETSC_DEFAULT_INTEGER,PETSC_DEFAULT_INTEGER,ierr)call EPSSolve(eps,ierr)call EPSDestroy(eps,ierr)* At the EPSSolve line, i get the following error: *[0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------[0]PETSC ERROR: Floating point exception[0]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite at end of function: Parameter number 3[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html <http://www.mcs.anl.gov/petsc/documentation/faq.html> for trouble shooting.[0]PETSC ERROR: Petsc Release Version 3.11.1, Apr, 12, 2019* I am using the options *-st_pc_factor_shift_type NONZERO -st_pc_factor_shift_amount 1* ( else I end up getting the "zero pivot in LU factorization" error ). I outputted my matrix to matlab and confirmed that the null space is empty and the matrix is not singular. I am not sure why I'm getting this error. Could you provide me a hint as to how to solve this problem. Sincerely, Pranay.
