Actual source code: test2.c

  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2013, 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 one matrix.\n\n";

 24: #include <slepcst.h>

 28: int main(int argc,char **argv)
 29: {
 30:   Mat            A,B,mat[1];
 31:   ST             st;
 32:   Vec            v,w;
 33:   STType         type;
 34:   PetscScalar    value[3],sigma,tau;
 35:   PetscInt       n=10,i,Istart,Iend,col[3];
 36:   PetscBool      FirstBlock=PETSC_FALSE,LastBlock=PETSC_FALSE;

 39:   SlepcInitialize(&argc,&argv,(char*)0,help);
 40:   PetscOptionsGetInt(NULL,"-n",&n,NULL);
 41:   PetscPrintf(PETSC_COMM_WORLD,"\n1-D Laplacian, n=%D\n\n",n);

 43:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 44:      Compute the operator matrix for the 1-D Laplacian
 45:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 47:   MatCreate(PETSC_COMM_WORLD,&A);
 48:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
 49:   MatSetFromOptions(A);
 50:   MatSetUp(A);

 52:   MatGetOwnershipRange(A,&Istart,&Iend);
 53:   if (Istart==0) FirstBlock=PETSC_TRUE;
 54:   if (Iend==n) LastBlock=PETSC_TRUE;
 55:   value[0]=-1.0; value[1]=2.0; value[2]=-1.0;
 56:   for (i=(FirstBlock? Istart+1: Istart); i<(LastBlock? Iend-1: Iend); i++) {
 57:     col[0]=i-1; col[1]=i; col[2]=i+1;
 58:     MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);
 59:   }
 60:   if (LastBlock) {
 61:     i=n-1; col[0]=n-2; col[1]=n-1;
 62:     MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);
 63:   }
 64:   if (FirstBlock) {
 65:     i=0; col[0]=0; col[1]=1; value[0]=2.0; value[1]=-1.0;
 66:     MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);
 67:   }

 69:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 70:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
 71:   MatGetVecs(A,&v,&w);
 72:   VecSet(v,1.0);

 74:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 75:                 Create the spectral transformation object
 76:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 78:   STCreate(PETSC_COMM_WORLD,&st);
 79:   mat[0] = A;
 80:   STSetOperators(st,1,mat);
 81:   STSetFromOptions(st);

 83:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 84:               Apply the transformed operator for several ST's
 85:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 87:   /* shift, sigma=0.0 */
 88:   STSetUp(st);
 89:   STGetType(st,&type);
 90:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
 91:   STApply(st,v,w);
 92:   VecView(w,NULL);

 94:   /* shift, sigma=0.1 */
 95:   sigma = 0.1;
 96:   STSetShift(st,sigma);
 97:   STGetShift(st,&sigma);
 98:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%G\n",PetscRealPart(sigma));
 99:   STApply(st,v,w);
100:   VecView(w,NULL);

102:   /* sinvert, sigma=0.1 */
103:   STPostSolve(st);   /* undo changes if inplace */
104:   STSetType(st,STSINVERT);
105:   STGetType(st,&type);
106:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
107:   STGetShift(st,&sigma);
108:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%G\n",PetscRealPart(sigma));
109:   STApply(st,v,w);
110:   VecView(w,NULL);

112:   /* sinvert, sigma=-0.5 */
113:   sigma = -0.5;
114:   STSetShift(st,sigma);
115:   STGetShift(st,&sigma);
116:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%G\n",PetscRealPart(sigma));
117:   STApply(st,v,w);
118:   VecView(w,NULL);

120:   /* cayley, sigma=-0.5, tau=-0.5 (equal to sigma by default) */
121:   STPostSolve(st);   /* undo changes if inplace */
122:   STSetType(st,STCAYLEY);
123:   STSetUp(st);
124:   STGetType(st,&type);
125:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
126:   STGetShift(st,&sigma);
127:   STCayleyGetAntishift(st,&tau);
128:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%G, antishift=%G\n",PetscRealPart(sigma),PetscRealPart(tau));
129:   STApply(st,v,w);
130:   VecView(w,NULL);

132:   /* cayley, sigma=1.1, tau=1.1 (still equal to sigma) */
133:   sigma = 1.1;
134:   STSetShift(st,sigma);
135:   STGetShift(st,&sigma);
136:   STCayleyGetAntishift(st,&tau);
137:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%G, antishift=%G\n",PetscRealPart(sigma),PetscRealPart(tau));
138:   STApply(st,v,w);
139:   VecView(w,NULL);

141:   /* cayley, sigma=1.1, tau=-1.0 */
142:   tau = -1.0;
143:   STCayleySetAntishift(st,tau);
144:   STGetShift(st,&sigma);
145:   STCayleyGetAntishift(st,&tau);
146:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%G, antishift=%G\n",PetscRealPart(sigma),PetscRealPart(tau));
147:   STApply(st,v,w);
148:   VecView(w,NULL);

150:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
151:                   Check inner product matrix in Cayley
152:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
153:   STGetBilinearForm(st,&B);
154:   MatMult(B,v,w);
155:   VecView(w,NULL);

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