Actual source code: test1.c

slepc-3.17.2 2022-08-09
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, 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 ST with shell matrices.\n\n";

 13: #include <slepcst.h>

 15: static PetscErrorCode MatGetDiagonal_Shell(Mat S,Vec diag);
 16: static PetscErrorCode MatMultTranspose_Shell(Mat S,Vec x,Vec y);
 17: static PetscErrorCode MatMult_Shell(Mat S,Vec x,Vec y);
 18: static PetscErrorCode MatDuplicate_Shell(Mat S,MatDuplicateOption op,Mat *M);

 20: static PetscErrorCode MyShellMatCreate(Mat *A,Mat *M)
 21: {
 22:   MPI_Comm       comm;
 23:   PetscInt       n;

 26:   MatGetSize(*A,&n,NULL);
 27:   PetscObjectGetComm((PetscObject)*A,&comm);
 28:   MatCreateShell(comm,PETSC_DECIDE,PETSC_DECIDE,n,n,A,M);
 29:   MatShellSetOperation(*M,MATOP_MULT,(void(*)(void))MatMult_Shell);
 30:   MatShellSetOperation(*M,MATOP_MULT_TRANSPOSE,(void(*)(void))MatMultTranspose_Shell);
 31:   MatShellSetOperation(*M,MATOP_GET_DIAGONAL,(void(*)(void))MatGetDiagonal_Shell);
 32:   MatShellSetOperation(*M,MATOP_DUPLICATE,(void(*)(void))MatDuplicate_Shell);
 33:   PetscFunctionReturn(0);
 34: }

 36: int main(int argc,char **argv)
 37: {
 38:   Mat            A,S,mat[1];
 39:   ST             st;
 40:   Vec            v,w;
 41:   STType         type;
 42:   KSP            ksp;
 43:   PC             pc;
 44:   PetscScalar    sigma;
 45:   PetscInt       n=10,i,Istart,Iend;

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

 51:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 52:      Compute the operator matrix for the 1-D Laplacian
 53:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 55:   MatCreate(PETSC_COMM_WORLD,&A);
 56:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
 57:   MatSetFromOptions(A);
 58:   MatSetUp(A);

 60:   MatGetOwnershipRange(A,&Istart,&Iend);
 61:   for (i=Istart;i<Iend;i++) {
 62:     if (i>0) MatSetValue(A,i,i-1,-1.0,INSERT_VALUES);
 63:     if (i<n-1) MatSetValue(A,i,i+1,-1.0,INSERT_VALUES);
 64:     MatSetValue(A,i,i,2.0,INSERT_VALUES);
 65:   }
 66:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 67:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

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

 72:   /* work vectors */
 73:   MatCreateVecs(A,&v,&w);
 74:   VecSet(v,1.0);

 76:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 77:                 Create the spectral transformation object
 78:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 80:   STCreate(PETSC_COMM_WORLD,&st);
 81:   mat[0] = S;
 82:   STSetMatrices(st,1,mat);
 83:   STSetTransform(st,PETSC_TRUE);
 84:   STSetFromOptions(st);

 86:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 87:               Apply the transformed operator for several ST's
 88:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 90:   /* shift, sigma=0.0 */
 91:   STSetUp(st);
 92:   STGetType(st,&type);
 93:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
 94:   STApply(st,v,w);
 95:   VecView(w,NULL);
 96:   STApplyTranspose(st,v,w);
 97:   VecView(w,NULL);

 99:   /* shift, sigma=0.1 */
100:   sigma = 0.1;
101:   STSetShift(st,sigma);
102:   STGetShift(st,&sigma);
103:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
104:   STApply(st,v,w);
105:   VecView(w,NULL);

107:   /* sinvert, sigma=0.1 */
108:   STPostSolve(st);   /* undo changes if inplace */
109:   STSetType(st,STSINVERT);
110:   STGetKSP(st,&ksp);
111:   KSPSetType(ksp,KSPGMRES);
112:   KSPGetPC(ksp,&pc);
113:   PCSetType(pc,PCJACOBI);
114:   STGetType(st,&type);
115:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
116:   STGetShift(st,&sigma);
117:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
118:   STApply(st,v,w);
119:   VecView(w,NULL);

121:   /* sinvert, sigma=-0.5 */
122:   sigma = -0.5;
123:   STSetShift(st,sigma);
124:   STGetShift(st,&sigma);
125:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
126:   STApply(st,v,w);
127:   VecView(w,NULL);

129:   STDestroy(&st);
130:   MatDestroy(&A);
131:   MatDestroy(&S);
132:   VecDestroy(&v);
133:   VecDestroy(&w);
134:   SlepcFinalize();
135:   return 0;
136: }

138: static PetscErrorCode MatMult_Shell(Mat S,Vec x,Vec y)
139: {
140:   Mat               *A;

143:   MatShellGetContext(S,&A);
144:   MatMult(*A,x,y);
145:   PetscFunctionReturn(0);
146: }

148: static PetscErrorCode MatMultTranspose_Shell(Mat S,Vec x,Vec y)
149: {
150:   Mat               *A;

153:   MatShellGetContext(S,&A);
154:   MatMultTranspose(*A,x,y);
155:   PetscFunctionReturn(0);
156: }

158: static PetscErrorCode MatGetDiagonal_Shell(Mat S,Vec diag)
159: {
160:   Mat               *A;

163:   MatShellGetContext(S,&A);
164:   MatGetDiagonal(*A,diag);
165:   PetscFunctionReturn(0);
166: }

168: static PetscErrorCode MatDuplicate_Shell(Mat S,MatDuplicateOption op,Mat *M)
169: {
170:   Mat            *A;

173:   MatShellGetContext(S,&A);
174:   MyShellMatCreate(A,M);
175:   PetscFunctionReturn(0);
176: }

178: /*TEST

180:    test:
181:       suffix: 1
182:       args: -st_matmode {{inplace shell}}
183:       output_file: output/test1_1.out
184:       requires: !single

186: TEST*/