Actual source code: test33.c
slepc-3.13.3 2020-06-14
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2020, Universitat Politecnica de Valencia, Spain
6: This file is part of SLEPc.
7: SLEPc is distributed under a 2-clause BSD license (see LICENSE).
8: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
9: */
11: static char help[] = "Test interface to external package BLZPACK.\n\n"
12: "This is based on ex12.c. The command line options are:\n"
13: " -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
14: " -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";
16: #include <slepceps.h>
18: int main(int argc,char **argv)
19: {
20: Mat A,B; /* matrices */
21: EPS eps; /* eigenproblem solver context */
22: ST st; /* spectral transformation context */
23: KSP ksp;
24: PC pc;
25: PetscInt N,n=35,m,Istart,Iend,II,nev,i,j,bs,nsteps;
26: PetscBool flag;
27: PetscReal int0,int1;
30: SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
32: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
33: PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
34: if (!flag) m=n;
35: N = n*m;
36: PetscPrintf(PETSC_COMM_WORLD,"\nSpectrum-slicing test, N=%D (%Dx%D grid)\n\n",N,n,m);
38: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
39: Compute the matrices that define the eigensystem, Ax=kBx
40: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
42: MatCreate(PETSC_COMM_WORLD,&A);
43: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
44: MatSetFromOptions(A);
45: MatSetUp(A);
47: MatCreate(PETSC_COMM_WORLD,&B);
48: MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N);
49: MatSetFromOptions(B);
50: MatSetUp(B);
52: MatGetOwnershipRange(A,&Istart,&Iend);
53: for (II=Istart;II<Iend;II++) {
54: i = II/n; j = II-i*n;
55: if (i>0) { MatSetValue(A,II,II-n,-1.0,INSERT_VALUES); }
56: if (i<m-1) { MatSetValue(A,II,II+n,-1.0,INSERT_VALUES); }
57: if (j>0) { MatSetValue(A,II,II-1,-1.0,INSERT_VALUES); }
58: if (j<n-1) { MatSetValue(A,II,II+1,-1.0,INSERT_VALUES); }
59: MatSetValue(A,II,II,4.0,INSERT_VALUES);
60: MatSetValue(B,II,II,2.0,INSERT_VALUES);
61: }
62: if (Istart==0) {
63: MatSetValue(B,0,0,6.0,INSERT_VALUES);
64: MatSetValue(B,0,1,-1.0,INSERT_VALUES);
65: MatSetValue(B,1,0,-1.0,INSERT_VALUES);
66: MatSetValue(B,1,1,1.0,INSERT_VALUES);
67: }
69: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
70: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
71: MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
72: MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
74: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
75: Create the eigensolver and set various options
76: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
78: EPSCreate(PETSC_COMM_WORLD,&eps);
79: EPSSetOperators(eps,A,B);
80: EPSSetProblemType(eps,EPS_GHEP);
81: EPSSetType(eps,EPSBLZPACK);
83: /*
84: Set interval and other settings for spectrum slicing
85: */
86: EPSSetWhichEigenpairs(eps,EPS_ALL);
87: int0 = 1.1; int1 = 1.2;
88: EPSSetInterval(eps,int0,int1);
89: EPSSetDimensions(eps,100,PETSC_DEFAULT,PETSC_DEFAULT);
90: EPSGetST(eps,&st);
91: STSetType(st,STSINVERT);
92: STGetKSP(st,&ksp);
93: KSPGetPC(ksp,&pc);
94: KSPSetType(ksp,KSPPREONLY);
95: PCSetType(pc,PCCHOLESKY);
97: EPSBlzpackSetBlockSize(eps,4);
98: EPSBlzpackSetNSteps(eps,20);
99: EPSSetFromOptions(eps);
101: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
102: Compute all eigenvalues in interval and display info
103: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
105: EPSSolve(eps);
106: EPSBlzpackGetBlockSize(eps,&bs);
107: EPSBlzpackGetNSteps(eps,&nsteps);
108: PetscPrintf(PETSC_COMM_WORLD," Using block size %D, maximum number of steps %D\n",bs,nsteps);
109: EPSGetDimensions(eps,&nev,NULL,NULL);
110: EPSGetInterval(eps,&int0,&int1);
111: PetscPrintf(PETSC_COMM_WORLD," Found %D eigenvalues in interval [%g,%g]\n",nev,(double)int0,(double)int1);
113: EPSErrorView(eps,EPS_ERROR_ABSOLUTE,NULL);
115: EPSDestroy(&eps);
116: MatDestroy(&A);
117: MatDestroy(&B);
118: SlepcFinalize();
119: return ierr;
120: }
122: /*TEST
124: build:
125: requires: blzpack
127: test:
128: suffix: 1
129: requires: blzpack
131: TEST*/