PCHPDDMSchurPreType#

Synopsis#

typedef enum {
  PC_HPDDM_SCHUR_PRE_LEAST_SQUARES,
  PC_HPDDM_SCHUR_PRE_GENEO,
} PCHPDDMSchurPreType;

PC_HPDDM_SCHUR_PRE_LEAST_SQUARES (default) - only with a near-zero A11 block and A10 = A01^T; a preconditioner for solving A01^T A00^-1 A01 x = b is built by approximating the Schur complement with (inv(sqrt(diag(A00))) A01)^T (inv(sqrt(diag(A00))) A01) and by considering the associated linear least squares problem
PC_HPDDM_SCHUR_PRE_GENEO - only with A10 = A01^T, PCHPDDMSetAuxiliaryMat() called on the PC of the A00 block, and if A11 is nonzero, then PCHPDDMSetAuxiliaryMat() must be called on the associated PC as well (it is built automatically for the user otherwise); the Schur complement PC is set internally to PCKSP, with the prefix -fieldsplit_1_pc_hpddm_; the operator associated to the PC is spectrally equivalent to the original Schur complement

advanced