File diffuse.c

RCS Header: /cvsroot/rheoplast/diffuse.c,v 1.31 2006/02/10 01:02:46 hazelsct Exp

This uses the new explicit timestepping framework to solve the diffusion equation in finite differences really, really fast. (Yes, diffusion is boring, but you gotta start somewhere. :-)

Included Files

#include "timestep.h"
- #include </usr/lib/petsc/include/petscsnes.h>
- #include </usr/lib/petsc/include/petscda.h>
- #include </usr/lib/petsc/include/petscblaslapack.h>
- #include <stdlib.h>

#include <illuminator.h>

#include </usr/lib/petsc/include/petscblaslapack.h>

Preprocessor definitions

#define DPRINTF( fmt, args... )

Typedef AppCtx

typedef struct {...} AppCtx

`struct`
`{`
`DA theda;`
`Vec global;`
`Vec local;`
`PetscScalar mesh_fourier_x;`
`PetscScalar mesh_fourier_y;`
`PetscScalar mesh_fourier_z;`
`int plotsteps;`
`PetscTruth contours;`
`PetscTruth twodee;`
`PetscViewer theviewer;`
`CommStyle style;`
`}`

Local Variables

help
PETSc help string, printed when run with -help.

static char help[]

Global Function func_boundary_line()

void func_boundary_line ( PetscScalar* x, PetscScalar* func, PetscScalar* temp, PetscTruth** mixed_constraints, PetscScalar time, int points, int gxm, int gym, int gzm, int xs, int ys, int zs, int xm, int nx, int ny, int nz, void* user, int side )

Global Function func_interior_line()

void func_interior_line ( PetscScalar* x, PetscScalar* func, PetscScalar* temp, PetscTruth** mixed_constraints, PetscScalar time, int points, int gxm, int gym, int gzm, int xs, int ys, int zs, int xm, int nx, int ny, int nz, void* user )

Global Function jack_interior_line()

void jack_interior_line ( PetscScalar* x, PetscScalar* temp, Mat jack, PetscScalar time, int points, int gxm, int gym, int gzm, int xs, int ys, int zs, int xm, int nx, int ny, int nz, int firstrow, void* user )

Global Function main()

int main ( int argc, char* argv[] )

Global Function step_interior_line()

This performs one explicit timestep for a line of data in the 2-D or 3-D array. In this simple example, it uses BLAS functions (defined in petscblaslapack.h) to do this extremely fast. Fastest explicit diffusion solver you'll find!

void step_interior_line ( PetscScalar* old, PetscScalar* new, PetscScalar* temps, PetscTruth** mixed_constraints, PetscScalar time, int points, int gxm, int gym, int gzm, int xs, int ys, int zs, int xm, int nx, int ny, int nz, void* user )

PetscScalar* old: Field variable array in previous timestep.
PetscScalar* new: Field variable array to fill in new timestep.
PetscScalar* temps: Temporary parameters (empty here) calculated by temp_parameters_line.
PetscTruth** mixed_constraints: Arrays of boolean variables indicating constraint equations in mixed timestep-constraint fields.
PetscScalar time: Current simulation time.
int points: Number of points to calculate at.
int gxm: Overall x-width of the array (for y increment).
int gym: Overall y-width of the array (for z increment).
int gzm: Overall z-width of the array (zero if 2-D).
int xs: Starting x-coordinate of the line.
int ys: Starting y-coordinate of the line.
int zs: Starting z-coordinate of the line.
int xm: Width of the interior part of the line.
int nx: Overall x-width of the entire global array.
int ny: Overall y-width of the entire global array.
int nz: Overall z-width of the entire global array (zero if 2-D).
void* user: User data structure pointer.

Global Function temp_parameters_boundary_line()

void temp_parameters_boundary_line ( PetscScalar* x, PetscScalar* temp, PetscScalar time, int points, int gxm, int gym, int gzm, int xs, int ys, int zs, int xm, int nx, int ny, int nz, void* user, int side )