1 static char help[] = "Tests 1D Gauss-Lobatto-Legendre discretization on [-1, 1].\n\n"; 2 3 #include <petscdt.h> 4 #include <petscviewer.h> 5 6 int main(int argc,char **argv) 7 { 8 9 PetscInt n = 3,i; 10 PetscReal *la_nodes,*la_weights,*n_nodes,*n_weights; 11 12 CHKERRQ(PetscInitialize(&argc,&argv,(char*)0,help)); 13 CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 14 15 CHKERRQ(PetscMalloc1(n,&la_nodes)); 16 CHKERRQ(PetscMalloc1(n,&la_weights)); 17 CHKERRQ(PetscMalloc1(n,&n_nodes)); 18 CHKERRQ(PetscMalloc1(n,&n_weights)); 19 CHKERRQ(PetscDTGaussLobattoLegendreQuadrature(n,PETSCGAUSSLOBATTOLEGENDRE_VIA_LINEAR_ALGEBRA,la_nodes,la_weights)); 20 21 CHKERRQ(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Gauss-Lobatto-Legendre nodes and weights computed via linear algebra: \n")); 22 CHKERRQ(PetscRealView(n,la_nodes,PETSC_VIEWER_STDOUT_SELF)); 23 CHKERRQ(PetscRealView(n,la_weights,PETSC_VIEWER_STDOUT_SELF)); 24 CHKERRQ(PetscDTGaussLobattoLegendreQuadrature(n,PETSCGAUSSLOBATTOLEGENDRE_VIA_NEWTON,n_nodes,n_weights)); 25 CHKERRQ(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Gauss-Lobatto-Legendre nodes and weights computed via Newton: \n")); 26 CHKERRQ(PetscRealView(n,n_nodes,PETSC_VIEWER_STDOUT_SELF)); 27 CHKERRQ(PetscRealView(n,n_weights,PETSC_VIEWER_STDOUT_SELF)); 28 29 for (i=0; i<n; i++) { 30 la_nodes[i] -= n_nodes[i]; 31 la_weights[i] -= n_weights[i]; 32 } 33 CHKERRQ(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_SELF,"Difference: \n")); 34 CHKERRQ(PetscRealView(n,la_nodes,PETSC_VIEWER_STDOUT_SELF)); 35 CHKERRQ(PetscRealView(n,la_weights,PETSC_VIEWER_STDOUT_SELF)); 36 37 CHKERRQ(PetscFree(la_nodes)); 38 CHKERRQ(PetscFree(la_weights)); 39 CHKERRQ(PetscFree(n_nodes)); 40 CHKERRQ(PetscFree(n_weights)); 41 42 CHKERRQ(PetscFinalize()); 43 return 0; 44 } 45 46 /*TEST 47 48 test: 49 50 TEST*/ 51