poisson.c @@ -1,7 +1,7 @@ ALL : ex15 shell CFLAGS= -std=c99 -include ${PETSC_DIR}/bmake/common/base +include ${PETSC_DIR}/conf/base nk : nk.o chkopts ${CLINKER} -o nk nk.o ${PETSC_LIB} @@ -14,3 +14,6 @@ shell : shell.o chkopts cheb : cheb.o chebyshev.o chkopts ${CLINKER} -o cheb cheb.o chebyshev.o -lfftw3 ${PETSC_LIB} + +poisson : poisson.o chebyshev.o chkopts + ${CLINKER} -o poisson poisson.o chebyshev.o -lfftw3 ${PETSC_LIB} Makefile @@ -17,7 +17,7 @@ int main(int argc,char **args) { Vec x,b,u; /* approx solution, RHS, exact solution */ Mat A; - Vec x2,b2,u2; /* approx solution, RHS, exact solution */ + Vec x2,b2,u2,du2; /* approx solution, RHS, exact solution */ Mat A2; KSP ksp; /* linear solver context */ PC pc; /* preconditioner context */ @@ -45,7 +45,7 @@ int main(int argc,char **args) ierr = VecDuplicate(b,&x);CHKERRQ(ierr); ierr = MatCreateChebD1(PETSC_COMM_WORLD, x, b, - FFTW_ESTIMATE | FFTW_PRESERVE_INPUT, &A); CHKERRQ(ierr); + FFTW_ESTIMATE, &A); CHKERRQ(ierr); int dims[] = { m, n, p }; // ierr = VecCreate(PETSC_COMM_WORLD, &u2);CHKERRQ(ierr); @@ -53,8 +53,9 @@ int main(int argc,char **args) // ierr = VecSetFromOptions(u2);CHKERRQ(ierr); ierr = VecCreateSeq(PETSC_COMM_WORLD, m * n * p, &u2); CHKERRQ(ierr); ierr = VecDuplicate(u2, &b2);CHKERRQ(ierr); - ierr = VecDuplicate(b2, &x2);CHKERRQ(ierr); - ierr = MatCreateCheb(PETSC_COMM_WORLD, 3, d, dims, FFTW_ESTIMATE | FFTW_PRESERVE_INPUT, + ierr = VecDuplicate(u2, &du2);CHKERRQ(ierr); + ierr = VecDuplicate(u2, &x2);CHKERRQ(ierr); + ierr = MatCreateCheb(PETSC_COMM_WORLD, 3, d, dims, FFTW_ESTIMATE, x2, b2, &A2); CHKERRQ(ierr); ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr); @@ -70,7 +71,9 @@ int main(int argc,char **args) ierr = VecRestoreArray(u, &a); CHKERRQ(ierr); // 2-D solution function + double *e; ierr = VecGetArray(u2, &a); CHKERRQ(ierr); + ierr = VecGetArray(du2, &e); CHKERRQ(ierr); for (int i=0; i < m; i++) { double x = (m==1) ? 0 : cos (i * PI / (m-1)); for (int j=0; j < n; j++) { @@ -78,13 +81,18 @@ int main(int argc,char **args) for (int k=0; k < p; k++) { double z = (p==1) ? 0 : cos (k * PI / (p-1)); a[(i*n + j) * p + k] = exp(x) + exp(y) + exp(z); + switch (d) { + case 0: e[(i*n + j) * p + k] = exp(x); break; + case 1: e[(i*n + j) * p + k] = exp(y); break; + case 2: e[(i*n + j) * p + k] = exp(z); break; + } } } } ierr = VecRestoreArray(u2, &a); CHKERRQ(ierr); + ierr = VecRestoreArray(du2, &e); CHKERRQ(ierr); ierr = MatMult(A, u, b); CHKERRQ(ierr); - ierr = MatMult(A2, u2, b2); CHKERRQ(ierr); // ierr = KSPSolve(ksp,b,x);CHKERRQ(ierr); ierr = VecCopy(b, x); CHKERRQ(ierr); @@ -94,11 +102,20 @@ int main(int argc,char **args) //ierr = PetscPrintf(PETSC_COMM_WORLD,"Norm of error %A iterations %D\n",norm,its);CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"Norm of error %A\n",norm);CHKERRQ(ierr); + ierr = MatMult(A2, u2, b2); CHKERRQ(ierr); + ierr = VecCopy(b2, x2); CHKERRQ(ierr); + + ierr = VecAXPY(x2,none,du2);CHKERRQ(ierr); + ierr = VecNorm(x2,NORM_INFINITY,&norm);CHKERRQ(ierr); + // ierr = KSPGetIterationNumber(ksp,&its);CHKERRQ(ierr); + //ierr = PetscPrintf(PETSC_COMM_WORLD,"Norm of error %A iterations %D\n",norm,its);CHKERRQ(ierr); + ierr = PetscPrintf(PETSC_COMM_WORLD,"Norm of error %A\n",norm);CHKERRQ(ierr); + /* /\* ierr = VecView(x, PETSC_VIEWER_STDOUT_SELF); CHKERRQ(ierr); *\/ */ - printf("\n"); - ierr = VecView(b, PETSC_VIEWER_STDOUT_SELF); CHKERRQ(ierr); - printf("\n"); - ierr = VecView(b2, PETSC_VIEWER_STDOUT_SELF); CHKERRQ(ierr); + /* printf("\n"); */ + /* ierr = VecView(b, PETSC_VIEWER_STDOUT_SELF); CHKERRQ(ierr); */ + /* printf("\n"); */ + /* ierr = VecView(b2, PETSC_VIEWER_STDOUT_SELF); CHKERRQ(ierr); */ /* Free work space. All PETSc objects should be destroyed when they cheb.c @@ -123,9 +123,9 @@ PetscErrorCode MatCreateCheb(MPI_Comm comm, int rank, int tr, int *dim, unsigned ierr = VecGetArray(vx, &x); CHKERRQ(ierr); ierr = VecGetArray(vy, &y); CHKERRQ(ierr); const fftw_r2r_kind redft00 = FFTW_REDFT00, rodft00 = FFTW_RODFT00; - c->p_forward = fftw_plan_guru_r2r(1, &(c->tdim), c->rank-1, c->dim, x, c->work, &redft00, flag); + c->p_forward = fftw_plan_guru_r2r(1, &(c->tdim), c->rank-1, c->dim, x, c->work, &redft00, flag | FFTW_PRESERVE_INPUT); fftw_iodim tdim1 = c->tdim; tdim1.n -= 2; // we need a modified tdim to come back. - c->p_backward = fftw_plan_guru_r2r(1, &tdim1, c->rank-1, c->dim, c->work + tdim1.os, y + tdim1.is, &rodft00, flag); + c->p_backward = fftw_plan_guru_r2r(1, &tdim1, c->rank-1, c->dim, c->work + tdim1.os, y + tdim1.is, &rodft00, flag | FFTW_DESTROY_INPUT); ierr = VecRestoreArray(vx, &x); CHKERRQ(ierr); ierr = VecRestoreArray(vy, &y); CHKERRQ(ierr); @@ -153,38 +153,39 @@ PetscErrorCode ChebMult(Mat A, Vec vx, Vec vy) { fftw_execute_r2r(c->p_forward, x, c->work); + double N = (double)n; ierr = PetscMemzero(ind, (c->rank - 1) * sizeof(int)); CHKERRQ(ierr); int offset = 0; for (bool done = false; !done; ) { + int ix0 = offset; + int ixn = offset + n * c->tdim.is; + y[ix0] = 0.0; + y[ixn] = 0.0; + double s = 1.0; for (int i = 1; i < n; i++) { int ix = offset + i * c->tdim.is; - c->work[ix] *= (double)i; + double I = (double)i; + c->work[ix] *= I; + y[ix0] += I * c->work[ix]; + y[ixn] += s * I * c->work[ix]; + s = -s; } + y[ix0] = 0.5 * c->work[ixn] * N + y[ix0] / n; + y[ixn] = y[ixn] / N + 0.5 * s * N * c->work[ixn]; perform_carry(c, ind, &offset, &done); } fftw_execute_r2r(c->p_backward, c->work + c->tdim.os, y + c->tdim.is); - double N = (double)n; double pin = PI / N; ierr = PetscMemzero(ind, (c->rank - 1) * sizeof(int)); CHKERRQ(ierr); offset = 0; for (bool done = false; !done; ) { - int ix0 = offset; - int ixn = offset + n * c->tdim.is; - y[ix0] = 0.0; - y[ixn] = 0.0; - double s = 1.0; for (int i = 1; i < n; i++) { int ix = offset + i * c->tdim.is; double I = (double)i; y[ix] /= 2 * n * sqrt(1.0 - PetscSqr(cos(I * pin))); - y[ix0] += I * c->work[ix]; - y[ixn] += s * I * c->work[ix]; - s = -s; } - y[ix0] = 0.5 * c->work[ixn] * N + y[ix0] / n; - y[ixn] = y[ixn] / N + 0.5 * s * N * c->work[ixn]; perform_carry(c, ind, &offset, &done); } chebyshev.c b2d95fbfd5e5711669d16e02c710a4b2169aed3a Jed Brown jed@59A2.org http://github.com/jedbrown/spectral-petsc/commit/92d68dd3b8a7929e26dd6f77da703d9554b7b838 92d68dd3b8a7929e26dd6f77da703d9554b7b838 2008-03-03T14:34:00-08:00 2008-03-03T14:34:00-08:00 Poisson solver. darcs-hash:20080303223426-40437-d68e6bd220058e767326782d29634ec83d089f16.gz e81693ca8748ee0549aca2628e94ce3111edfe01 Jed Brown jed@59A2.org