Actual source code: test7.c

slepc-3.21.1 2024-04-26
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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 matrix square root.\n\n";

 13: #include <slepcfn.h>

 15: /*
 16:    Compute matrix square root B = sqrtm(A)
 17:    Check result as norm(B*B-A)
 18:  */
 19: PetscErrorCode TestMatSqrt(FN fn,Mat A,PetscViewer viewer,PetscBool verbose,PetscBool inplace)
 20: {
 21:   PetscScalar    tau,eta;
 22:   PetscReal      nrm;
 23:   PetscBool      set,flg;
 24:   PetscInt       n;
 25:   Mat            S,R,Acopy;
 26:   Vec            v,f0;

 28:   PetscFunctionBeginUser;
 29:   PetscCall(MatGetSize(A,&n,NULL));
 30:   PetscCall(MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&S));
 31:   PetscCall(PetscObjectSetName((PetscObject)S,"S"));
 32:   PetscCall(FNGetScale(fn,&tau,&eta));
 33:   /* compute square root */
 34:   if (inplace) {
 35:     PetscCall(MatCopy(A,S,SAME_NONZERO_PATTERN));
 36:     PetscCall(MatIsHermitianKnown(A,&set,&flg));
 37:     if (set && flg) PetscCall(MatSetOption(S,MAT_HERMITIAN,PETSC_TRUE));
 38:     PetscCall(FNEvaluateFunctionMat(fn,S,NULL));
 39:   } else {
 40:     PetscCall(MatDuplicate(A,MAT_COPY_VALUES,&Acopy));
 41:     PetscCall(FNEvaluateFunctionMat(fn,A,S));
 42:     /* check that A has not been modified */
 43:     PetscCall(MatAXPY(Acopy,-1.0,A,SAME_NONZERO_PATTERN));
 44:     PetscCall(MatNorm(Acopy,NORM_1,&nrm));
 45:     if (nrm>100*PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Warning: the input matrix has changed by %g\n",(double)nrm));
 46:     PetscCall(MatDestroy(&Acopy));
 47:   }
 48:   if (verbose) {
 49:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Matrix A - - - - - - - -\n"));
 50:     PetscCall(MatView(A,viewer));
 51:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Computed sqrtm(A) - - - - - - -\n"));
 52:     PetscCall(MatView(S,viewer));
 53:   }
 54:   /* check error ||S*S-A||_F */
 55:   PetscCall(MatMatMult(S,S,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&R));
 56:   if (eta!=1.0) PetscCall(MatScale(R,1.0/(eta*eta)));
 57:   PetscCall(MatAXPY(R,-tau,A,SAME_NONZERO_PATTERN));
 58:   PetscCall(MatNorm(R,NORM_FROBENIUS,&nrm));
 59:   if (nrm<100*PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"||S*S-A||_F < 100*eps\n"));
 60:   else PetscCall(PetscPrintf(PETSC_COMM_WORLD,"||S*S-A||_F = %g\n",(double)nrm));
 61:   /* check FNEvaluateFunctionMatVec() */
 62:   PetscCall(MatCreateVecs(A,&v,&f0));
 63:   PetscCall(MatGetColumnVector(S,f0,0));
 64:   PetscCall(FNEvaluateFunctionMatVec(fn,A,v));
 65:   PetscCall(VecAXPY(v,-1.0,f0));
 66:   PetscCall(VecNorm(v,NORM_2,&nrm));
 67:   if (nrm>100*PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Warning: the norm of f(A)*e_1-v is %g\n",(double)nrm));
 68:   PetscCall(MatDestroy(&S));
 69:   PetscCall(MatDestroy(&R));
 70:   PetscCall(VecDestroy(&v));
 71:   PetscCall(VecDestroy(&f0));
 72:   PetscFunctionReturn(PETSC_SUCCESS);
 73: }

 75: int main(int argc,char **argv)
 76: {
 77:   FN             fn;
 78:   Mat            A=NULL;
 79:   PetscInt       i,j,n=10;
 80:   PetscScalar    *As;
 81:   PetscViewer    viewer;
 82:   PetscBool      verbose,inplace,matcuda;
 83:   PetscRandom    myrand;
 84:   PetscReal      v;

 86:   PetscFunctionBeginUser;
 87:   PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
 88:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
 89:   PetscCall(PetscOptionsHasName(NULL,NULL,"-verbose",&verbose));
 90:   PetscCall(PetscOptionsHasName(NULL,NULL,"-inplace",&inplace));
 91:   PetscCall(PetscOptionsHasName(NULL,NULL,"-matcuda",&matcuda));
 92:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Matrix square root, n=%" PetscInt_FMT ".\n",n));

 94:   /* Create function object */
 95:   PetscCall(FNCreate(PETSC_COMM_WORLD,&fn));
 96:   PetscCall(FNSetType(fn,FNSQRT));
 97:   PetscCall(FNSetFromOptions(fn));

 99:   /* Set up viewer */
100:   PetscCall(PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer));
101:   PetscCall(FNView(fn,viewer));
102:   if (verbose) PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB));

104:   /* Create matrix */
105:   if (matcuda) {
106: #if defined(PETSC_HAVE_CUDA)
107:     PetscCall(MatCreateSeqDenseCUDA(PETSC_COMM_SELF,n,n,NULL,&A));
108: #endif
109:   } else PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,n,n,NULL,&A));
110:   PetscCall(PetscObjectSetName((PetscObject)A,"A"));

112:   /* Compute square root of a symmetric matrix A */
113:   PetscCall(MatDenseGetArray(A,&As));
114:   for (i=0;i<n;i++) As[i+i*n]=2.5;
115:   for (j=1;j<3;j++) {
116:     for (i=0;i<n-j;i++) { As[i+(i+j)*n]=1.0; As[(i+j)+i*n]=1.0; }
117:   }
118:   PetscCall(MatDenseRestoreArray(A,&As));
119:   PetscCall(MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE));
120:   PetscCall(TestMatSqrt(fn,A,viewer,verbose,inplace));

122:   /* Repeat with upper triangular A */
123:   PetscCall(MatDenseGetArray(A,&As));
124:   for (j=1;j<3;j++) {
125:     for (i=0;i<n-j;i++) As[(i+j)+i*n]=0.0;
126:   }
127:   PetscCall(MatDenseRestoreArray(A,&As));
128:   PetscCall(MatSetOption(A,MAT_HERMITIAN,PETSC_FALSE));
129:   PetscCall(TestMatSqrt(fn,A,viewer,verbose,inplace));

131:   /* Repeat with non-symmetic A */
132:   PetscCall(PetscRandomCreate(PETSC_COMM_WORLD,&myrand));
133:   PetscCall(PetscRandomSetFromOptions(myrand));
134:   PetscCall(PetscRandomSetInterval(myrand,0.0,1.0));
135:   PetscCall(MatDenseGetArray(A,&As));
136:   for (j=1;j<3;j++) {
137:     for (i=0;i<n-j;i++) {
138:       PetscCall(PetscRandomGetValueReal(myrand,&v));
139:       As[(i+j)+i*n]=v;
140:     }
141:   }
142:   PetscCall(MatDenseRestoreArray(A,&As));
143:   PetscCall(PetscRandomDestroy(&myrand));
144:   PetscCall(MatSetOption(A,MAT_HERMITIAN,PETSC_FALSE));
145:   PetscCall(TestMatSqrt(fn,A,viewer,verbose,inplace));

147:   PetscCall(MatDestroy(&A));
148:   PetscCall(FNDestroy(&fn));
149:   PetscCall(SlepcFinalize());
150:   return 0;
151: }

153: /*TEST

155:    testset:
156:       args: -fn_scale .05,2 -n 100
157:       filter: grep -v "computing matrix functions"
158:       output_file: output/test7_1.out
159:       requires: !__float128
160:       timeoutfactor: 2
161:       test:
162:          suffix: 1
163:          args: -fn_method {{0 1 2}}
164:       test:
165:          suffix: 1_sadeghi
166:          args: -fn_method 3
167:          requires: !single
168:       test:
169:          suffix: 1_cuda
170:          args: -fn_method 2 -matcuda
171:          requires: cuda !single
172:       test:
173:          suffix: 1_magma
174:          args: -fn_method {{1 3}} -matcuda
175:          requires: cuda magma !single
176:       test:
177:          suffix: 2
178:          args: -inplace -fn_method {{0 1 2}}
179:       test:
180:          suffix: 2_sadeghi
181:          args: -inplace -fn_method 3
182:          requires: !single
183:       test:
184:          suffix: 2_cuda
185:          args: -inplace -fn_method 2 -matcuda
186:          requires: cuda !single
187:       test:
188:          suffix: 2_magma
189:          args: -inplace -fn_method {{1 3}} -matcuda
190:          requires: cuda magma !single

192:    testset:
193:       nsize: 3
194:       args: -fn_scale .05,2 -n 100 -fn_parallel synchronized
195:       filter: grep -v "computing matrix functions" | grep -v "SYNCHRONIZED" | sed -e "s/3 MPI processes/1 MPI process/g"
196:       requires: !__float128
197:       output_file: output/test7_1.out
198:       test:
199:          suffix: 3
200:       test:
201:          suffix: 3_inplace
202:          args: -inplace

204: TEST*/