1: /*
2: MFN routines related to the solution process.
4: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
5: SLEPc - Scalable Library for Eigenvalue Problem Computations
6: Copyright (c) 2002-2015, Universitat Politecnica de Valencia, Spain
8: This file is part of SLEPc.
10: SLEPc is free software: you can redistribute it and/or modify it under the
11: terms of version 3 of the GNU Lesser General Public License as published by
12: the Free Software Foundation.
14: SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
15: WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
16: FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
17: more details.
19: You should have received a copy of the GNU Lesser General Public License
20: along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
21: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
22: */
24: #include <slepc/private/mfnimpl.h> /*I "slepcmfn.h" I*/
28: /*@
29: MFNSolve - Solves the matrix function problem. Given a vector b, the
30: vector x = f(A)*b is returned.
32: Collective on MFN 34: Input Parameters:
35: + mfn - matrix function context obtained from MFNCreate()
36: - b - the right hand side vector
38: Output Parameter:
39: . x - the solution (this may be the same vector as b, then b will be
40: overwritten with the answer)
42: Options Database Keys:
43: + -mfn_view - print information about the solver used
44: . -mfn_view_mat binary - save the matrix to the default binary viewer
45: . -mfn_view_rhs binary - save right hand side vector to the default binary viewer
46: . -mfn_view_solution binary - save computed solution vector to the default binary viewer
47: - -mfn_converged_reason - print reason for convergence, and number of iterations
49: Notes:
50: The matrix A is specified with MFNSetOperator().
51: The function f is specified with MFNSetFN().
53: Level: beginner
55: .seealso: MFNCreate(), MFNSetUp(), MFNDestroy(), MFNSetTolerances(),
56: MFNSetOperator(), MFNSetFN()
57: @*/
58: PetscErrorCode MFNSolve(MFN mfn,Vec b,Vec x) 59: {
68: VecLocked(x,3);
70: /* call setup */
71: MFNSetUp(mfn);
72: mfn->its = 0;
74: MFNMonitor(mfn,mfn->its,0);
75: MFNViewFromOptions(mfn,NULL,"-mfn_view_pre");
77: /* call solver */
78: PetscLogEventBegin(MFN_Solve,mfn,b,x,0);
79: VecLockPush(b);
80: (*mfn->ops->solve)(mfn,b,x);
81: VecLockPop(b);
82: PetscLogEventEnd(MFN_Solve,mfn,b,x,0);
84: if (!mfn->reason) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_PLIB,"Internal error, solver returned without setting converged reason");
86: if (mfn->errorifnotconverged && mfn->reason < 0) SETERRQ(PetscObjectComm((PetscObject)mfn),PETSC_ERR_NOT_CONVERGED,"MFNSolve has not converged");
88: /* various viewers */
89: MFNViewFromOptions(mfn,NULL,"-mfn_view");
90: MFNReasonViewFromOptions(mfn);
91: MatViewFromOptions(mfn->A,(PetscObject)mfn,"-mfn_view_mat");
92: VecViewFromOptions(b,(PetscObject)mfn,"-mfn_view_rhs");
93: VecViewFromOptions(x,(PetscObject)mfn,"-mfn_view_solution");
94: return(0);
95: }
99: /*@
100: MFNGetIterationNumber - Gets the current iteration number. If the
101: call to MFNSolve() is complete, then it returns the number of iterations
102: carried out by the solution method.
104: Not Collective
106: Input Parameter:
107: . mfn - the matrix function context
109: Output Parameter:
110: . its - number of iterations
112: Level: intermediate
114: Note:
115: During the i-th iteration this call returns i-1. If MFNSolve() is
116: complete, then parameter "its" contains either the iteration number at
117: which convergence was successfully reached, or failure was detected.
118: Call MFNGetConvergedReason() to determine if the solver converged or
119: failed and why.
121: .seealso: MFNGetConvergedReason(), MFNSetTolerances()
122: @*/
123: PetscErrorCode MFNGetIterationNumber(MFN mfn,PetscInt *its)124: {
128: *its = mfn->its;
129: return(0);
130: }
134: /*@
135: MFNGetConvergedReason - Gets the reason why the MFNSolve() iteration was
136: stopped.
138: Not Collective
140: Input Parameter:
141: . mfn - the matrix function context
143: Output Parameter:
144: . reason - negative value indicates diverged, positive value converged
146: Possible values for reason:
147: + MFN_CONVERGED_TOL - converged up to tolerance
148: . MFN_DIVERGED_ITS - required more than its to reach convergence
149: - MFN_DIVERGED_BREAKDOWN - generic breakdown in method
151: Note:
152: Can only be called after the call to MFNSolve() is complete.
154: Level: intermediate
156: .seealso: MFNSetTolerances(), MFNSolve(), MFNConvergedReason, MFNSetErrorIfNotConverged()
157: @*/
158: PetscErrorCode MFNGetConvergedReason(MFN mfn,MFNConvergedReason *reason)159: {
163: *reason = mfn->reason;
164: return(0);
165: }