Actual source code: test1.c

slepc-3.5.2 2014-10-10
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2014, 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 ST with shell matrices.\n\n";

 24: #include <slepcst.h>

 26: static PetscErrorCode MatGetDiagonal_Shell(Mat S,Vec diag);
 27: static PetscErrorCode MatMultTranspose_Shell(Mat S,Vec x,Vec y);
 28: static PetscErrorCode MatMult_Shell(Mat S,Vec x,Vec y);
 29: static PetscErrorCode MatDuplicate_Shell(Mat S,MatDuplicateOption op,Mat *M);

 33: static PetscErrorCode MyShellMatCreate(Mat *A,Mat *M)
 34: {
 36:   MPI_Comm       comm;
 37:   PetscInt       n;

 40:   MatGetSize(*A,&n,NULL);
 41:   PetscObjectGetComm((PetscObject)*A,&comm);
 42:   MatCreateShell(comm,PETSC_DECIDE,PETSC_DECIDE,n,n,A,M);
 43:   MatSetFromOptions(*M);
 44:   MatShellSetOperation(*M,MATOP_MULT,(void(*)())MatMult_Shell);
 45:   MatShellSetOperation(*M,MATOP_MULT_TRANSPOSE,(void(*)())MatMultTranspose_Shell);
 46:   MatShellSetOperation(*M,MATOP_GET_DIAGONAL,(void(*)())MatGetDiagonal_Shell);
 47:   MatShellSetOperation(*M,MATOP_DUPLICATE,(void(*)())MatDuplicate_Shell);
 48:   return(0);
 49: }

 53: int main(int argc,char **argv)
 54: {
 55:   Mat            A,S,mat[1];
 56:   ST             st;
 57:   Vec            v,w;
 58:   STType         type;
 59:   KSP            ksp;
 60:   PC             pc;
 61:   PetscScalar    value[3],sigma;
 62:   PetscInt       n=10,i,Istart,Iend,col[3];
 63:   PetscBool      FirstBlock=PETSC_FALSE,LastBlock=PETSC_FALSE;

 66:   SlepcInitialize(&argc,&argv,(char*)0,help);
 67:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
 68:   PetscPrintf(PETSC_COMM_WORLD,"\n1-D Laplacian with shell matrices, n=%D\n\n",n);

 70:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 71:      Compute the operator matrix for the 1-D Laplacian
 72:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 74:   MatCreate(PETSC_COMM_WORLD,&A);
 75:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
 76:   MatSetFromOptions(A);
 77:   MatSetUp(A);

 79:   MatGetOwnershipRange(A,&Istart,&Iend);
 80:   if (Istart==0) FirstBlock=PETSC_TRUE;
 81:   if (Iend==n) LastBlock=PETSC_TRUE;
 82:   value[0]=-1.0; value[1]=2.0; value[2]=-1.0;
 83:   for (i=(FirstBlock? Istart+1: Istart); i<(LastBlock? Iend-1: Iend); i++) {
 84:     col[0]=i-1; col[1]=i; col[2]=i+1;
 85:     MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);
 86:   }
 87:   if (LastBlock) {
 88:     i=n-1; col[0]=n-2; col[1]=n-1;
 89:     MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);
 90:   }
 91:   if (FirstBlock) {
 92:     i=0; col[0]=0; col[1]=1; value[0]=2.0; value[1]=-1.0;
 93:     MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);
 94:   }

 96:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 97:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 99:   /* create the shell version of A */
100:   MyShellMatCreate(&A,&S);

102:   /* work vectors */
103:   MatGetVecs(A,&v,&w);
104:   VecSet(v,1.0);

106:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
107:                 Create the spectral transformation object
108:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

110:   STCreate(PETSC_COMM_WORLD,&st);
111:   mat[0] = S;
112:   STSetOperators(st,1,mat);
113:   STSetFromOptions(st);


116:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
117:               Apply the transformed operator for several ST's
118:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

120:   /* shift, sigma=0.0 */
121:   STSetUp(st);
122:   STGetType(st,&type);
123:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
124:   STApply(st,v,w);
125:   VecView(w,NULL);

127:   /* shift, sigma=0.1 */
128:   sigma = 0.1;
129:   STSetShift(st,sigma);
130:   STGetShift(st,&sigma);
131:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
132:   STApply(st,v,w);
133:   VecView(w,NULL);

135:   /* sinvert, sigma=0.1 */
136:   STPostSolve(st);   /* undo changes if inplace */
137:   STSetType(st,STSINVERT);
138:   STGetKSP(st,&ksp);
139:   KSPSetType(ksp,KSPGMRES);
140:   KSPGetPC(ksp,&pc);
141:   PCSetType(pc,PCJACOBI);
142:   STGetType(st,&type);
143:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
144:   STGetShift(st,&sigma);
145:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
146:   STApply(st,v,w);
147:   VecView(w,NULL);

149:   /* sinvert, sigma=-0.5 */
150:   sigma = -0.5;
151:   STSetShift(st,sigma);
152:   STGetShift(st,&sigma);
153:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
154:   STApply(st,v,w);
155:   VecView(w,NULL);

157:   STDestroy(&st);
158:   MatDestroy(&A);
159:   MatDestroy(&S);
160:   VecDestroy(&v);
161:   VecDestroy(&w);
162:   SlepcFinalize();
163:   return 0;
164: }

168: static PetscErrorCode MatMult_Shell(Mat S,Vec x,Vec y)
169: {
170:   PetscErrorCode    ierr;
171:   Mat               *A;

174:   MatShellGetContext(S,&A);
175:   MatMult(*A,x,y);
176:   return(0);
177: }

181: static PetscErrorCode MatMultTranspose_Shell(Mat S,Vec x,Vec y)
182: {
183:   PetscErrorCode    ierr;
184:   Mat               *A;

187:   MatShellGetContext(S,&A);
188:   MatMultTranspose(*A,x,y);
189:   return(0);
190: }

194: static PetscErrorCode MatGetDiagonal_Shell(Mat S,Vec diag)
195: {
196:   PetscErrorCode    ierr;
197:   Mat               *A;

200:   MatShellGetContext(S,&A);
201:   MatGetDiagonal(*A,diag);
202:   return(0);
203: }

207: static PetscErrorCode MatDuplicate_Shell(Mat S,MatDuplicateOption op,Mat *M)
208: {
210:   Mat            *A;

213:   MatShellGetContext(S,&A);
214:   MyShellMatCreate(A,M);
215:   return(0);
216: }