/*$Id: ex1e.c,v 1.15 2001/09/11 18:05:40 bsmith Exp $*/ /* Program usage: mpirun ex1 [-help] [all PETSc options] */ static char help[] = "Demonstrates various vector routines.\n\n"; /*T Concepts: vectors^basic routines; Processors: n T*/ /* This uses the PETSc _ error checking routines. Put _ before the PETSc function call and __ after the call (or ___ in a subroutine, not the main program). This is equivalent to using the ierr = ... CHKERRQ(ierr); macros Include "petscvec.h" so that we can use vectors. Note that this file automatically includes: petsc.h - base PETSc routines petscis.h - index sets petscsys.h - system routines petscviewer.h - viewers */ #include "petscvec.h" #if defined(PETSC_USE_SINGLE) #define PETSC_EPS 1.e-5 #else #define PETSC_EPS 1.e-10 #endif #undef __FUNCT__ #define __FUNCT__ "main" int main(int argc,char **argv) { Vec x, y, w; /* vectors */ Vec *z; /* array of vectors */ PetscReal norm, v, v1, v2; int n = 20; PetscTruth flg; PetscScalar one = 1.0, two = 2.0, three = 3.0, dots[3], dot; _ PetscInitialize(&argc,&argv,(char*)0,help);___ _ PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);___ /* Create a vector, specifying only its global dimension. When using VecCreate(), VecSetSizes() and VecSetFromOptions(), the vector format (currently parallel, shared, or sequential) is determined at runtime. Also, the parallel partitioning of the vector is determined by PETSc at runtime. Routines for creating particular vector types directly are: VecCreateSeq() - uniprocessor vector VecCreateMPI() - distributed vector, where the user can determine the parallel partitioning VecCreateShared() - parallel vector that uses shared memory (available only on the SGI); otherwise, is the same as VecCreateMPI() With VecCreate(), VecSetSizes() and VecSetFromOptions() the option -vec_type mpi or -vec_type shared causes the particular type of vector to be formed. */ _ VecCreate(PETSC_COMM_WORLD,&x);___ _ VecSetSizes(x,PETSC_DECIDE,n);___ _ VecSetFromOptions(x);___ /* Duplicate some work vectors (of the same format and partitioning as the initial vector). */ _ VecDuplicate(x,&y);___ _ VecDuplicate(x,&w);___ /* Duplicate more work vectors (of the same format and partitioning as the initial vector). Here we duplicate an array of vectors, which is often more convenient than duplicating individual ones. */ _ VecDuplicateVecs(x,3,&z);___ /* Set the vectors to entries to a constant value. */ _ VecSet(&one,x);___ _ VecSet(&two,y);___ _ VecSet(&one,z[0]);___ _ VecSet(&two,z[1]);___ _ VecSet(&three,z[2]);___ /* Demonstrate various basic vector routines. */ _ VecDot(x,x,&dot);___ _ VecMDot(3,x,z,dots);___ /* Note: If using a complex numbers version of PETSc, then PETSC_USE_COMPLEX is defined in the makefiles; otherwise, (when using real numbers) it is undefined. */ #if defined(PETSC_USE_COMPLEX) _ PetscPrintf(PETSC_COMM_WORLD,"Vector length %d\n", int (PetscRealPart(dot)));___ _ PetscPrintf(PETSC_COMM_WORLD,"Vector length %d %d %d\n",(int)PetscRealPart(dots[0]), (int)PetscRealPart(dots[1]),(int)PetscRealPart(dots[2]));___ #else _ PetscPrintf(PETSC_COMM_WORLD,"Vector length %d\n",(int) dot);___ _ PetscPrintf(PETSC_COMM_WORLD,"Vector length %d %d %d\n",(int)dots[0], (int)dots[1],(int)dots[2]);___ #endif _ PetscPrintf(PETSC_COMM_WORLD,"All other values should be near zero\n");___ _ VecScale(&two,x);___ _ VecNorm(x,NORM_2,&norm);___ v = norm-2.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecScale %g\n",v);___ _ VecCopy(x,w);___ _ VecNorm(w,NORM_2,&norm);___ v = norm-2.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecCopy %g\n",v);___ _ VecAXPY(&three,x,y);___ _ VecNorm(y,NORM_2,&norm);___ v = norm-8.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecAXPY %g\n",v);___ _ VecAYPX(&two,x,y);___ _ VecNorm(y,NORM_2,&norm);___ v = norm-18.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecAYPX %g\n",v);___ _ VecSwap(x,y);___ _ VecNorm(y,NORM_2,&norm);___ v = norm-2.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecSwap %g\n",v);___ _ VecNorm(x,NORM_2,&norm);___ v = norm-18.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecSwap %g\n",v);___ _ VecWAXPY(&two,x,y,w);___ _ VecNorm(w,NORM_2,&norm);___ v = norm-38.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecWAXPY %g\n",v);___ _ VecPointwiseMult(y,x,w);___ _ VecNorm(w,NORM_2,&norm);___ v = norm-36.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecPointwiseMult %g\n",v);___ _ VecPointwiseDivide(x,y,w);___ _ VecNorm(w,NORM_2,&norm);___ v = norm-9.0*sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecPointwiseDivide %g\n",v);___ dots[0] = one; dots[1] = three; dots[2] = two; _ VecSet(&one,x);___ _ VecMAXPY(3,dots,x,z);___ _ VecNorm(z[0],NORM_2,&norm);___ v = norm-sqrt((PetscReal) n); if (v > -PETSC_EPS && v < PETSC_EPS) v = 0.0; _ VecNorm(z[1],NORM_2,&norm);___ v1 = norm-2.0*sqrt((PetscReal) n); if (v1 > -PETSC_EPS && v1 < PETSC_EPS) v1 = 0.0; _ VecNorm(z[2],NORM_2,&norm);___ v2 = norm-3.0*sqrt((PetscReal) n); if (v2 > -PETSC_EPS && v2 < PETSC_EPS) v2 = 0.0; _ PetscPrintf(PETSC_COMM_WORLD,"VecMAXPY %g %g %g \n",v,v1,v2);___ /* Test whether vector has been corrupted (just to demonstrate this routine) not needed in most application codes. */ _ VecValid(x,&flg);___ if (!flg) SETERRQ(1,"Corrupted vector."); /* Free work space. All PETSc objects should be destroyed when they are no longer needed. */ _ VecDestroy(x);___ _ VecDestroy(y);___ _ VecDestroy(w);___ _ VecDestroyVecs(z,3);___ _ PetscFinalize();___ return 0; }