1 /*$Id: smg.c,v 1.24 2001/08/07 03:03:36 balay Exp $*/ 2 /* 3 Additive Multigrid V Cycle routine 4 */ 5 #include "src/ksp/pc/impls/mg/mgimpl.h" 6 7 /* 8 MGACycle_Private - Given an MG structure created with MGCreate() runs 9 one cycle down through the levels and back up. Applys 10 the smoothers in an additive manner. 11 12 Iput Parameters: 13 . mg - structure created with MGCreate(). 14 15 */ 16 #undef __FUNCT__ 17 #define __FUNCT__ "MGACycle_Private" 18 int MGACycle_Private(MG *mg) 19 { 20 int i,l = mg[0]->levels,ierr; 21 PetscScalar zero = 0.0; 22 23 PetscFunctionBegin; 24 /* compute RHS on each level */ 25 for (i=l-1; i>0; i--) { 26 ierr = MatRestrict(mg[i]->restrct,mg[i]->b,mg[i-1]->b);CHKERRQ(ierr); 27 } 28 /* solve seperately on each level */ 29 for (i=0; i<l; i++) { 30 ierr = VecSet(&zero,mg[i]->x);CHKERRQ(ierr); 31 if (mg[i]->eventsolve) {ierr = PetscLogEventBegin(mg[i]->eventsolve,0,0,0,0);CHKERRQ(ierr);} 32 ierr = KSPSetRhs(mg[i]->smoothd,mg[i]->b);CHKERRQ(ierr); 33 ierr = KSPSetSolution(mg[i]->smoothd,mg[i]->x);CHKERRQ(ierr); 34 ierr = KSPSolve(mg[i]->smoothd);CHKERRQ(ierr); 35 if (mg[i]->eventsolve) {ierr = PetscLogEventEnd(mg[i]->eventsolve,0,0,0,0);CHKERRQ(ierr);} 36 } 37 for (i=1; i<l; i++) { 38 ierr = MatInterpolateAdd(mg[i]->interpolate,mg[i-1]->x,mg[i]->x,mg[i]->x);CHKERRQ(ierr); 39 } 40 PetscFunctionReturn(0); 41 } 42