Actual source code: test5.c
slepc-3.7.1 2016-05-27
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain
6: This file is part of SLEPc.
8: SLEPc is free software: you can redistribute it and/or modify it under the
9: terms of version 3 of the GNU Lesser General Public License as published by
10: the Free Software Foundation.
12: SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
13: WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14: FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15: more details.
17: You should have received a copy of the GNU Lesser General Public License
18: along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
19: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
20: */
22: static char help[] = "Test matrix rational function.\n\n";
24: #include <slepcfn.h>
28: /*
29: Compute matrix rational function B = q(A)\p(A)
30: */
31: PetscErrorCode TestMatRational(FN fn,Mat A,PetscViewer viewer,PetscBool verbose,PetscBool inplace)
32: {
34: PetscBool set,flg;
35: PetscInt n;
36: Mat F;
37: Vec v,f0;
38: PetscReal nrm;
41: MatGetSize(A,&n,NULL);
42: MatCreateSeqDense(PETSC_COMM_SELF,n,n,NULL,&F);
43: PetscObjectSetName((PetscObject)F,"F");
44: /* compute square root */
45: if (inplace) {
46: MatCopy(A,F,SAME_NONZERO_PATTERN);
47: MatIsHermitianKnown(A,&set,&flg);
48: if (set && flg) { MatSetOption(F,MAT_HERMITIAN,PETSC_TRUE); }
49: FNEvaluateFunctionMat(fn,F,NULL);
50: } else {
51: FNEvaluateFunctionMat(fn,A,F);
52: }
53: if (verbose) {
54: PetscPrintf(PETSC_COMM_WORLD,"Matrix A - - - - - - - -\n");
55: MatView(A,viewer);
56: PetscPrintf(PETSC_COMM_WORLD,"Computed f(A) - - - - - - -\n");
57: MatView(F,viewer);
58: }
59: /* print matrix norm for checking */
60: MatNorm(F,NORM_1,&nrm);
61: PetscPrintf(PETSC_COMM_WORLD,"The 1-norm of f(A) is %g\n",(double)nrm);
62: /* check FNEvaluateFunctionMatVec() */
63: MatCreateVecs(A,&v,&f0);
64: MatGetColumnVector(F,f0,0);
65: FNEvaluateFunctionMatVec(fn,A,v);
66: VecAXPY(v,-1.0,f0);
67: VecNorm(v,NORM_2,&nrm);
68: if (nrm>100*PETSC_MACHINE_EPSILON) {
69: PetscPrintf(PETSC_COMM_WORLD,"Warning: the norm of f(A)*e_1-v is %g\n",(double)nrm);
70: }
71: MatDestroy(&F);
72: VecDestroy(&v);
73: VecDestroy(&f0);
74: return(0);
75: }
79: int main(int argc,char **argv)
80: {
82: FN fn;
83: Mat A;
84: PetscInt i,j,n=10,np,nq;
85: PetscScalar *As,p[10],q[10];
86: PetscViewer viewer;
87: PetscBool verbose,inplace;
89: SlepcInitialize(&argc,&argv,(char*)0,help);
90: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
91: PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
92: PetscOptionsHasName(NULL,NULL,"-inplace",&inplace);
93: PetscPrintf(PETSC_COMM_WORLD,"Matrix rational function, n=%D.\n",n);
95: /* Create rational function r(x)=p(x)/q(x) */
96: FNCreate(PETSC_COMM_WORLD,&fn);
97: FNSetType(fn,FNRATIONAL);
98: np = 2; nq = 3;
99: p[0] = -3.1; p[1] = 1.1;
100: q[0] = 1.0; q[1] = -2.0; q[2] = 3.5;
101: FNRationalSetNumerator(fn,np,p);
102: FNRationalSetDenominator(fn,nq,q);
103: FNSetFromOptions(fn);
105: /* Set up viewer */
106: PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
107: FNView(fn,viewer);
108: if (verbose) {
109: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
110: }
112: /* Create matrices */
113: MatCreateSeqDense(PETSC_COMM_SELF,n,n,NULL,&A);
114: PetscObjectSetName((PetscObject)A,"A");
116: /* Fill A with a symmetric Toeplitz matrix */
117: MatDenseGetArray(A,&As);
118: for (i=0;i<n;i++) As[i+i*n]=2.0;
119: for (j=1;j<3;j++) {
120: for (i=0;i<n-j;i++) { As[i+(i+j)*n]=1.0; As[(i+j)+i*n]=1.0; }
121: }
122: MatDenseRestoreArray(A,&As);
123: MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);
124: TestMatRational(fn,A,viewer,verbose,inplace);
126: /* Repeat with same matrix as non-symmetric */
127: MatSetOption(A,MAT_HERMITIAN,PETSC_FALSE);
128: TestMatRational(fn,A,viewer,verbose,inplace);
130: MatDestroy(&A);
131: FNDestroy(&fn);
132: SlepcFinalize();
133: return ierr;
134: }