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 STFILTER interface functions.\n\n"
 12:   "Based on ex2.\n"
 13:   "The command line options are:\n"
 14:   "  -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
 15:   "  -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";

 17: #include <slepceps.h>

 19: int main(int argc,char **argv)
 20: {
 21:   Mat            A;
 22:   EPS            eps;
 23:   ST             st;
 24:   PetscInt       N,n=10,m,Istart,Iend,II,i,j,degree;
 25:   PetscBool      flag,modify=PETSC_FALSE,terse;
 26:   PetscReal      inta,intb,rleft,rright;

 28:   PetscFunctionBeginUser;
 29:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
 30:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
 31:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag));
 32:   if (!flag) m=n;
 33:   N = n*m;
 34:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\n2-D Laplacian Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m));
 35:   PetscCall(PetscOptionsGetBool(NULL,NULL,"-modify",&modify,&flag));

 37:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 38:                     Create the 2-D Laplacian
 39:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 41:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
 42:   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N));
 43:   PetscCall(MatSetFromOptions(A));
 44:   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
 45:   for (II=Istart;II<Iend;II++) {
 46:     i = II/n; j = II-i*n;
 47:     if (i>0) PetscCall(MatSetValue(A,II,II-n,-1.0,INSERT_VALUES));
 48:     if (i<m-1) PetscCall(MatSetValue(A,II,II+n,-1.0,INSERT_VALUES));
 49:     if (j>0) PetscCall(MatSetValue(A,II,II-1,-1.0,INSERT_VALUES));
 50:     if (j<n-1) PetscCall(MatSetValue(A,II,II+1,-1.0,INSERT_VALUES));
 51:     PetscCall(MatSetValue(A,II,II,4.0,INSERT_VALUES));
 52:   }
 53:   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
 54:   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));

 56:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 57:                 Create the eigensolver and set various options
 58:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 60:   PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
 61:   PetscCall(EPSSetOperators(eps,A,NULL));
 62:   PetscCall(EPSSetProblemType(eps,EPS_HEP));
 63:   PetscCall(EPSSetType(eps,EPSKRYLOVSCHUR));
 64:   PetscCall(EPSSetWhichEigenpairs(eps,EPS_ALL));
 65:   PetscCall(EPSSetInterval(eps,0.5,1.3));
 66:   PetscCall(EPSGetST(eps,&st));
 67:   PetscCall(STSetType(st,STFILTER));
 68:   PetscCall(EPSSetFromOptions(eps));

 70:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 71:                 Solve the problem and display the solution
 72:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 74:   PetscCall(EPSSolve(eps));

 76:   /* print filter information */
 77:   PetscCall(PetscObjectTypeCompare((PetscObject)st,STFILTER,&flag));
 78:   if (flag) {
 79:     PetscCall(STFilterGetDegree(st,&degree));
 80:     PetscCall(PetscPrintf(PETSC_COMM_WORLD," Filter degree: %" PetscInt_FMT "\n",degree));
 81:     PetscCall(STFilterGetInterval(st,&inta,&intb));
 82:     PetscCall(STFilterGetRange(st,&rleft,&rright));
 83:     PetscCall(PetscPrintf(PETSC_COMM_WORLD," Requested interval: [%g,%g],  range: [%g,%g]\n\n",(double)inta,(double)intb,(double)rleft,(double)rright));
 84:   }

 86:   PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
 87:   if (terse) PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
 88:   else {
 89:     PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
 90:     PetscCall(EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD));
 91:     PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
 92:     PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
 93:   }

 95:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 96:               Solve the problem again after changing the matrix
 97:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 98:   if (modify) {
 99:     PetscCall(MatSetValue(A,0,0,0.3,INSERT_VALUES));
100:     PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
101:     PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
102:     PetscCall(EPSSetOperators(eps,A,NULL));
103:     PetscCall(EPSSolve(eps));
104:     PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
105:     if (terse) PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
106:     else {
107:       PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
108:       PetscCall(EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD));
109:       PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
110:       PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
111:     }
112:   }

114:   PetscCall(EPSDestroy(&eps));
115:   PetscCall(MatDestroy(&A));
116:   PetscCall(SlepcFinalize());
117:   return 0;
118: }

120: /*TEST

122:    test:
123:       suffix: 1
124:       args: -terse
125:       filter: sed -e "s/0.161982,7.83797/0.162007,7.83897/"
126:       requires: !single

128:    test:
129:       suffix: 2
130:       args: -modify -st_filter_range -0.5,8 -terse
131:       requires: !single

133:    test:
134:       suffix: 3
135:       args: -modify -terse
136:       filter: sed -e "s/0.161982,7.83797/0.162007,7.83897/"
137:       requires: !single

139: TEST*/