/*
Sets up a monitor that will display He as a function of space and cluster size for each time step
*/
PetscErrorCode MyMonitorSetUp(TS ts)
{
DM da;
PetscErrorCode ierr;
PetscInt xi,xs,xm,*idx,M,xj,cnt = 0,dof = 3*N + N*N;
const PetscInt *lx;
Vec C;
MyMonitorCtx *ctx;
PetscBool flg;
IS is;
char ycoor[32];
PetscReal valuebounds[4] = {0, 1.2, 0, 1.2};
PetscFunctionBeginUser;
ierr = PetscOptionsHasName(PETSC_NULL,"-mymonitor",&flg);CHKERRQ(ierr);
if (!flg) PetscFunctionReturn(0);
ierr = TSGetDM(ts,&da);CHKERRQ(ierr);
ierr = PetscNew(MyMonitorCtx,&ctx);CHKERRQ(ierr);
ierr = PetscViewerDrawOpen(((PetscObject)da)->comm,PETSC_NULL,"",PETSC_DECIDE,PETSC_DECIDE,600,400,&ctx->viewer);CHKERRQ(ierr);
ierr = DMDAGetCorners(da,&xs,PETSC_NULL,PETSC_NULL,&xm,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
ierr = DMDAGetInfo(da,PETSC_IGNORE,&M,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE);CHKERRQ(ierr);
ierr = DMDAGetOwnershipRanges(da,&lx,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
ierr = DMDACreate2d(((PetscObject)da)->comm,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_STAR,M,N,PETSC_DETERMINE,1,2,1,lx,PETSC_NULL,&ctx->da);CHKERRQ(ierr);
ierr = DMDASetFieldName(ctx->da,0,"He");CHKERRQ(ierr);
ierr = DMDASetFieldName(ctx->da,1,"V");CHKERRQ(ierr);
ierr = DMDASetCoordinateName(ctx->da,0,"X coordinate direction");CHKERRQ(ierr);
ierr = PetscSNPrintf(ycoor,32,"%D ... Cluster size ... 1",N);CHKERRQ(ierr);
ierr = DMDASetCoordinateName(ctx->da,1,ycoor);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(ctx->da,&ctx->He);CHKERRQ(ierr);
ierr = PetscMalloc(2*N*xm*sizeof(PetscInt),&idx);CHKERRQ(ierr);
cnt = 0;
for (xj=0; xj<N; xj++) {
for (xi=xs; xi<xs+xm; xi++) {
idx[cnt++] = dof*xi + xj;
idx[cnt++] = dof*xi + xj + N;
}
}
ierr = ISCreateGeneral(((PetscObject)ts)->comm,2*N*xm,idx,PETSC_OWN_POINTER,&is);CHKERRQ(ierr);
ierr = TSGetSolution(ts,&C);CHKERRQ(ierr);
ierr = VecScatterCreate(C,is,ctx->He,PETSC_NULL,&ctx->scatter);CHKERRQ(ierr);
ierr = ISDestroy(&is);CHKERRQ(ierr);
/* sets the bounds on the contour plot values so the colors mean the same thing for different timesteps */
ierr = PetscViewerDrawSetBounds(ctx->viewer,2,valuebounds);CHKERRQ(ierr);
ierr = TSMonitorSet(ts,MyMonitorMonitor,ctx,MyMonitorDestroy);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
PetscErrorCode PetscViewerSetFromOptions_Draw(PetscOptionItems *PetscOptionsObject,PetscViewer v)
{
PetscErrorCode ierr;
PetscReal bounds[16];
PetscInt nbounds = 16;
PetscBool flg;
PetscFunctionBegin;
ierr = PetscOptionsHead(PetscOptionsObject,"Draw PetscViewer Options");CHKERRQ(ierr);
ierr = PetscOptionsRealArray("-draw_bounds","Bounds to put on plots axis","PetscViewerDrawSetBounds",bounds,&nbounds,&flg);CHKERRQ(ierr);
if (flg) {
ierr = PetscViewerDrawSetBounds(v,nbounds/2,bounds);CHKERRQ(ierr);
}
ierr = PetscOptionsTail();CHKERRQ(ierr);
PetscFunctionReturn(0);
}
void PETSC_STDCALL petscviewerdrawsetbounds_(PetscViewer viewer,PetscInt *nbounds, PetscReal *bounds, int *__ierr ){
*__ierr = PetscViewerDrawSetBounds(
(PetscViewer)PetscToPointer((viewer) ),*nbounds,bounds);
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
int time; /* amount of loops */
struct in put;
PetscScalar rh; /* relative humidity */
PetscScalar x; /* memory varialbe for relative humidity calculation */
PetscScalar deep_grnd_temp; /* temperature of ground under top soil surface layer */
PetscScalar emma; /* absorption-emission constant for air */
PetscScalar pressure1 = 101300; /* surface pressure */
PetscScalar mixratio; /* mixing ratio */
PetscScalar airtemp; /* temperature of air near boundary layer inversion */
PetscScalar dewtemp; /* dew point temperature */
PetscScalar sfctemp; /* temperature at surface */
PetscScalar pwat; /* total column precipitable water */
PetscScalar cloudTemp; /* temperature at base of cloud */
AppCtx user; /* user-defined work context */
MonitorCtx usermonitor; /* user-defined monitor context */
PetscMPIInt rank,size;
TS ts;
SNES snes;
DM da;
Vec T,rhs; /* solution vector */
Mat J; /* Jacobian matrix */
PetscReal ftime,dt;
PetscInt steps,dof = 5;
PetscBool use_coloring = PETSC_TRUE;
MatFDColoring matfdcoloring = 0;
PetscBool monitor_off = PETSC_FALSE;
PetscInitialize(&argc,&argv,(char*)0,help);
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
/* Inputs */
readinput(&put);
sfctemp = put.Ts;
dewtemp = put.Td;
cloudTemp = put.Tc;
airtemp = put.Ta;
pwat = put.pwt;
if (!rank) PetscPrintf(PETSC_COMM_SELF,"Initial Temperature = %g\n",sfctemp); /* input surface temperature */
deep_grnd_temp = sfctemp - 10; /* set underlying ground layer temperature */
emma = emission(pwat); /* accounts for radiative effects of water vapor */
/* Converts from Fahrenheit to Celsuis */
sfctemp = fahr_to_cel(sfctemp);
airtemp = fahr_to_cel(airtemp);
dewtemp = fahr_to_cel(dewtemp);
cloudTemp = fahr_to_cel(cloudTemp);
deep_grnd_temp = fahr_to_cel(deep_grnd_temp);
/* Converts from Celsius to Kelvin */
sfctemp += 273;
airtemp += 273;
dewtemp += 273;
cloudTemp += 273;
deep_grnd_temp += 273;
/* Calculates initial relative humidity */
x = calcmixingr(dewtemp,pressure1);
mixratio = calcmixingr(sfctemp,pressure1);
rh = (x/mixratio)*100;
if (!rank) printf("Initial RH = %.1f percent\n\n",rh); /* prints initial relative humidity */
time = 3600*put.time; /* sets amount of timesteps to run model */
/* Configure PETSc TS solver */
/*------------------------------------------*/
/* Create grid */
ierr = DMDACreate2d(PETSC_COMM_WORLD,DMDA_BOUNDARY_PERIODIC,DMDA_BOUNDARY_PERIODIC,DMDA_STENCIL_STAR,-20,-20,
PETSC_DECIDE,PETSC_DECIDE,dof,1,NULL,NULL,&da);CHKERRQ(ierr);
ierr = DMDASetUniformCoordinates(da, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0);CHKERRQ(ierr);
/* Define output window for each variable of interest */
ierr = DMDASetFieldName(da,0,"Ts");CHKERRQ(ierr);
ierr = DMDASetFieldName(da,1,"Ta");CHKERRQ(ierr);
ierr = DMDASetFieldName(da,2,"u");CHKERRQ(ierr);
ierr = DMDASetFieldName(da,3,"v");CHKERRQ(ierr);
ierr = DMDASetFieldName(da,4,"p");CHKERRQ(ierr);
/* set values for appctx */
user.da = da;
user.Ts = sfctemp;
user.fract = put.fr; /* fraction of sky covered by clouds */
user.dewtemp = dewtemp; /* dew point temperature (mositure in air) */
user.csoil = 2000000; /* heat constant for layer */
user.dzlay = 0.08; /* thickness of top soil layer */
user.emma = emma; /* emission parameter */
user.wind = put.wnd; /* wind spped */
user.pressure1 = pressure1; /* sea level pressure */
user.airtemp = airtemp; /* temperature of air near boundar layer inversion */
user.Tc = cloudTemp; /* temperature at base of lowest cloud layer */
user.init = put.init; /* user chosen initiation scenario */
user.lat = 70*0.0174532; /* converts latitude degrees to latitude in radians */
user.deep_grnd_temp = deep_grnd_temp; /* temp in lowest ground layer */
/* set values for MonitorCtx */
usermonitor.drawcontours = PETSC_FALSE;
ierr = PetscOptionsHasName(NULL,"-drawcontours",&usermonitor.drawcontours);CHKERRQ(ierr);
if (usermonitor.drawcontours) {
PetscReal bounds[] = {1000.0,-1000., -1000.,-1000., 1000.,-1000., 1000.,-1000., 1000,-1000, 100700,100800};
ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,0,0,0,300,300,&usermonitor.drawviewer);CHKERRQ(ierr);
ierr = PetscViewerDrawSetBounds(usermonitor.drawviewer,dof,bounds);CHKERRQ(ierr);
}
usermonitor.interval = 1;
ierr = PetscOptionsGetInt(NULL,"-monitor_interval",&usermonitor.interval,NULL);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Extract global vectors from DA;
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = DMCreateGlobalVector(da,&T);CHKERRQ(ierr);
ierr = VecDuplicate(T,&rhs);CHKERRQ(ierr); /* r: vector to put the computed right hand side */
ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
ierr = TSSetType(ts,TSBEULER);CHKERRQ(ierr);
ierr = TSSetRHSFunction(ts,rhs,RhsFunc,&user);CHKERRQ(ierr);
/* Set Jacobian evaluation routine - use coloring to compute finite difference Jacobian efficiently */
ierr = DMSetMatType(da,MATAIJ);CHKERRQ(ierr);
ierr = DMCreateMatrix(da,&J);CHKERRQ(ierr);
ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
if (use_coloring) {
ISColoring iscoloring;
ierr = DMCreateColoring(da,IS_COLORING_GLOBAL,&iscoloring);CHKERRQ(ierr);
ierr = MatFDColoringCreate(J,iscoloring,&matfdcoloring);CHKERRQ(ierr);
ierr = MatFDColoringSetFromOptions(matfdcoloring);CHKERRQ(ierr);
ierr = MatFDColoringSetUp(J,iscoloring,matfdcoloring);CHKERRQ(ierr);
ierr = ISColoringDestroy(&iscoloring);CHKERRQ(ierr);
ierr = MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))SNESTSFormFunction,ts);CHKERRQ(ierr);
ierr = SNESSetJacobian(snes,J,J,SNESComputeJacobianDefaultColor,matfdcoloring);CHKERRQ(ierr);
} else {
ierr = SNESSetJacobian(snes,J,J,SNESComputeJacobianDefault,NULL);CHKERRQ(ierr);
}
/* Define what to print for ts_monitor option */
ierr = PetscOptionsHasName(NULL,"-monitor_off",&monitor_off);CHKERRQ(ierr);
if (!monitor_off) {
ierr = TSMonitorSet(ts,Monitor,&usermonitor,NULL);CHKERRQ(ierr);
}
ierr = FormInitialSolution(da,T,&user);CHKERRQ(ierr);
dt = TIMESTEP; /* initial time step */
ftime = TIMESTEP*time;
if (!rank) printf("time %d, ftime %g hour, TIMESTEP %g\n",time,ftime/3600,dt);
ierr = TSSetInitialTimeStep(ts,0.0,dt);CHKERRQ(ierr);
ierr = TSSetDuration(ts,time,ftime);CHKERRQ(ierr);
ierr = TSSetSolution(ts,T);CHKERRQ(ierr);
ierr = TSSetDM(ts,da);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set runtime options
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Solve nonlinear system
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSolve(ts,T);CHKERRQ(ierr);
ierr = TSGetSolveTime(ts,&ftime);CHKERRQ(ierr);
ierr = TSGetTimeStepNumber(ts,&steps);CHKERRQ(ierr);
if (!rank) PetscPrintf(PETSC_COMM_WORLD,"Solution T after %g hours %d steps\n",ftime/3600,steps);
if (matfdcoloring) {ierr = MatFDColoringDestroy(&matfdcoloring);CHKERRQ(ierr);}
if (usermonitor.drawcontours) {
ierr = PetscViewerDestroy(&usermonitor.drawviewer);CHKERRQ(ierr);
}
ierr = MatDestroy(&J);CHKERRQ(ierr);
ierr = VecDestroy(&T);CHKERRQ(ierr);
ierr = VecDestroy(&rhs);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
PetscFinalize();
return 0;
}
/*
This routine is not parallel
*/
PetscErrorCode MyMonitor(TS ts,PetscInt step,PetscReal time,Vec U,void *ptr)
{
UserCtx *ctx = (UserCtx*)ptr;
PetscDrawLG lg;
PetscErrorCode ierr;
PetscScalar *u;
PetscInt Mx,i,xs,xm,cnt;
PetscReal x,y,hx,pause,sx,len,max,xx[2],yy[2];
PetscDraw draw;
Vec localU;
DM da;
int colors[] = {PETSC_DRAW_YELLOW,PETSC_DRAW_RED,PETSC_DRAW_BLUE};
const char*const legend[] = {"-kappa (\\grad u,\\grad u)","(1 - u^2)^2"};
PetscDrawAxis axis;
PetscDrawViewPorts *ports;
PetscReal vbounds[] = {-1.1,1.1};
PetscFunctionBegin;
ierr = PetscViewerDrawSetBounds(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),1,vbounds);CHKERRQ(ierr);
ierr = PetscViewerDrawResize(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),1200,800);CHKERRQ(ierr);
ierr = TSGetDM(ts,&da);CHKERRQ(ierr);
ierr = DMGetLocalVector(da,&localU);CHKERRQ(ierr);
ierr = DMDAGetInfo(da,PETSC_IGNORE,&Mx,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE);CHKERRQ(ierr);
ierr = DMDAGetCorners(da,&xs,NULL,NULL,&xm,NULL,NULL);CHKERRQ(ierr);
hx = 1.0/(PetscReal)Mx; sx = 1.0/(hx*hx);
ierr = DMGlobalToLocalBegin(da,U,INSERT_VALUES,localU);CHKERRQ(ierr);
ierr = DMGlobalToLocalEnd(da,U,INSERT_VALUES,localU);CHKERRQ(ierr);
ierr = DMDAVecGetArrayRead(da,localU,&u);CHKERRQ(ierr);
ierr = PetscViewerDrawGetDrawLG(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),1,&lg);CHKERRQ(ierr);
ierr = PetscDrawLGGetDraw(lg,&draw);CHKERRQ(ierr);
ierr = PetscDrawCheckResizedWindow(draw);CHKERRQ(ierr);
if (!ctx->ports) {
ierr = PetscDrawViewPortsCreateRect(draw,1,3,&ctx->ports);CHKERRQ(ierr);
}
ports = ctx->ports;
ierr = PetscDrawLGGetAxis(lg,&axis);CHKERRQ(ierr);
ierr = PetscDrawLGReset(lg);CHKERRQ(ierr);
xx[0] = 0.0; xx[1] = 1.0; cnt = 2;
ierr = PetscOptionsGetRealArray(NULL,NULL,"-zoom",xx,&cnt,NULL);CHKERRQ(ierr);
xs = xx[0]/hx; xm = (xx[1] - xx[0])/hx;
/*
Plot the energies
*/
ierr = PetscDrawLGSetDimension(lg,1 + (ctx->allencahn ? 1 : 0));CHKERRQ(ierr);
ierr = PetscDrawLGSetColors(lg,colors+1);CHKERRQ(ierr);
ierr = PetscDrawViewPortsSet(ports,2);CHKERRQ(ierr);
x = hx*xs;
for (i=xs; i<xs+xm; i++) {
xx[0] = xx[1] = x;
yy[0] = PetscRealPart(.25*ctx->kappa*(u[i-1] - u[i+1])*(u[i-1] - u[i+1])*sx);
if (ctx->allencahn) yy[1] = .25*PetscRealPart((1. - u[i]*u[i])*(1. - u[i]*u[i]));
ierr = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr);
x += hx;
}
ierr = PetscDrawGetPause(draw,&pause);CHKERRQ(ierr);
ierr = PetscDrawSetPause(draw,0.0);CHKERRQ(ierr);
ierr = PetscDrawAxisSetLabels(axis,"Energy","","");CHKERRQ(ierr);
ierr = PetscDrawLGSetLegend(lg,legend);CHKERRQ(ierr);
ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
/*
Plot the forces
*/
ierr = PetscDrawViewPortsSet(ports,1);CHKERRQ(ierr);
ierr = PetscDrawLGReset(lg);CHKERRQ(ierr);
x = xs*hx;;
max = 0.;
for (i=xs; i<xs+xm; i++) {
xx[0] = xx[1] = x;
yy[0] = PetscRealPart(ctx->kappa*(u[i-1] + u[i+1] - 2.0*u[i])*sx);
max = PetscMax(max,PetscAbs(yy[0]));
if (ctx->allencahn) {
yy[1] = PetscRealPart(u[i] - u[i]*u[i]*u[i]);
max = PetscMax(max,PetscAbs(yy[1]));
}
ierr = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr);
x += hx;
}
ierr = PetscDrawAxisSetLabels(axis,"Right hand side","","");CHKERRQ(ierr);
ierr = PetscDrawLGSetLegend(lg,NULL);CHKERRQ(ierr);
ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
/*
Plot the solution
*/
ierr = PetscDrawLGSetDimension(lg,1);CHKERRQ(ierr);
ierr = PetscDrawViewPortsSet(ports,0);CHKERRQ(ierr);
ierr = PetscDrawLGReset(lg);CHKERRQ(ierr);
x = hx*xs;
ierr = PetscDrawLGSetLimits(lg,x,x+(xm-1)*hx,-1.1,1.1);CHKERRQ(ierr);
ierr = PetscDrawLGSetColors(lg,colors);CHKERRQ(ierr);
for (i=xs; i<xs+xm; i++) {
xx[0] = x;
yy[0] = PetscRealPart(u[i]);
ierr = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr);
x += hx;
}
ierr = PetscDrawAxisSetLabels(axis,"Solution","","");CHKERRQ(ierr);
ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
/*
Print the forces as arrows on the solution
*/
x = hx*xs;
cnt = xm/60;
cnt = (!cnt) ? 1 : cnt;
for (i=xs; i<xs+xm; i += cnt) {
y = PetscRealPart(u[i]);
len = .5*PetscRealPart(ctx->kappa*(u[i-1] + u[i+1] - 2.0*u[i])*sx)/max;
ierr = PetscDrawArrow(draw,x,y,x,y+len,PETSC_DRAW_RED);CHKERRQ(ierr);
if (ctx->allencahn) {
len = .5*PetscRealPart(u[i] - u[i]*u[i]*u[i])/max;
ierr = PetscDrawArrow(draw,x,y,x,y+len,PETSC_DRAW_BLUE);CHKERRQ(ierr);
}
x += cnt*hx;
}
ierr = DMDAVecRestoreArrayRead(da,localU,&x);CHKERRQ(ierr);
ierr = DMRestoreLocalVector(da,&localU);CHKERRQ(ierr);
ierr = PetscDrawStringSetSize(draw,.2,.2);CHKERRQ(ierr);
ierr = PetscDrawFlush(draw);CHKERRQ(ierr);
ierr = PetscDrawSetPause(draw,pause);CHKERRQ(ierr);
ierr = PetscDrawPause(draw);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
int main(int argc,char **argv)
{
TS ts; /* nonlinear solver */
Vec x,r; /* solution, residual vectors */
Mat J; /* Jacobian matrix */
PetscInt steps,Mx,maxsteps = 10000000;
PetscErrorCode ierr;
DM da;
MatFDColoring matfdcoloring;
ISColoring iscoloring;
PetscReal dt;
PetscReal vbounds[] = {-100000,100000,-1.1,1.1};
PetscBool wait;
Vec ul,uh;
SNES snes;
UserCtx ctx;
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Initialize program
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
ctx.kappa = 1.0;
ierr = PetscOptionsGetReal(NULL,"-kappa",&ctx.kappa,NULL);CHKERRQ(ierr);
ctx.cahnhillard = PETSC_FALSE;
ierr = PetscOptionsGetBool(NULL,NULL,"-cahn-hillard",&ctx.cahnhillard,NULL);CHKERRQ(ierr);
ierr = PetscViewerDrawSetBounds(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),2,vbounds);CHKERRQ(ierr);
ierr = PetscViewerDrawResize(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),600,600);CHKERRQ(ierr);
ctx.energy = 1;
/* ierr = PetscOptionsGetInt(NULL,NULL,"-energy",&ctx.energy,NULL);CHKERRQ(ierr); */
ierr = PetscOptionsGetInt(NULL,NULL,"-energy",&ctx.energy,NULL);CHKERRQ(ierr);
ctx.tol = 1.0e-8;
ierr = PetscOptionsGetReal(NULL,"-tol",&ctx.tol,NULL);CHKERRQ(ierr);
ctx.theta = .001;
ctx.theta_c = 1.0;
ierr = PetscOptionsGetReal(NULL,"-theta",&ctx.theta,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetReal(NULL,"-theta_c",&ctx.theta_c,NULL);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Create distributed array (DMDA) to manage parallel grid and vectors
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = DMDACreate1d(PETSC_COMM_WORLD, DM_BOUNDARY_PERIODIC, -10,2,2,NULL,&da);CHKERRQ(ierr);
ierr = DMSetFromOptions(da);CHKERRQ(ierr);
ierr = DMSetUp(da);CHKERRQ(ierr);
ierr = DMDASetFieldName(da,0,"Biharmonic heat equation: w = -kappa*u_xx");CHKERRQ(ierr);
ierr = DMDASetFieldName(da,1,"Biharmonic heat equation: u");CHKERRQ(ierr);
ierr = DMDAGetInfo(da,0,&Mx,0,0,0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
dt = 1.0/(10.*ctx.kappa*Mx*Mx*Mx*Mx);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Extract global vectors from DMDA; then duplicate for remaining
vectors that are the same types
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = DMCreateGlobalVector(da,&x);CHKERRQ(ierr);
ierr = VecDuplicate(x,&r);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Create timestepping solver context
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
ierr = TSSetDM(ts,da);CHKERRQ(ierr);
ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
ierr = TSSetIFunction(ts,NULL,FormFunction,&ctx);CHKERRQ(ierr);
ierr = TSSetDuration(ts,maxsteps,.02);CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_STEPOVER);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Create matrix data structure; set Jacobian evaluation routine
< Set Jacobian matrix data structure and default Jacobian evaluation
routine. User can override with:
-snes_mf : matrix-free Newton-Krylov method with no preconditioning
(unless user explicitly sets preconditioner)
-snes_mf_operator : form preconditioning matrix as set by the user,
but use matrix-free approx for Jacobian-vector
products within Newton-Krylov method
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr);
ierr = DMCreateColoring(da,IS_COLORING_GLOBAL,&iscoloring);CHKERRQ(ierr);
ierr = DMSetMatType(da,MATAIJ);CHKERRQ(ierr);
ierr = DMCreateMatrix(da,&J);CHKERRQ(ierr);
ierr = MatFDColoringCreate(J,iscoloring,&matfdcoloring);CHKERRQ(ierr);
ierr = ISColoringDestroy(&iscoloring);CHKERRQ(ierr);
ierr = MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))SNESTSFormFunction,ts);CHKERRQ(ierr);
ierr = MatFDColoringSetFromOptions(matfdcoloring);CHKERRQ(ierr);
ierr = MatFDColoringSetUp(J,iscoloring,matfdcoloring);CHKERRQ(ierr);
ierr = SNESSetJacobian(snes,J,J,SNESComputeJacobianDefaultColor,matfdcoloring);CHKERRQ(ierr);
{
ierr = VecDuplicate(x,&ul);CHKERRQ(ierr);
ierr = VecDuplicate(x,&uh);CHKERRQ(ierr);
ierr = VecStrideSet(ul,0,PETSC_NINFINITY);CHKERRQ(ierr);
ierr = VecStrideSet(ul,1,-1.0);CHKERRQ(ierr);
ierr = VecStrideSet(uh,0,PETSC_INFINITY);CHKERRQ(ierr);
ierr = VecStrideSet(uh,1,1.0);CHKERRQ(ierr);
ierr = TSVISetVariableBounds(ts,ul,uh);CHKERRQ(ierr);
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Customize nonlinear solver
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetType(ts,TSBEULER);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set initial conditions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = FormInitialSolution(da,x,ctx.kappa);CHKERRQ(ierr);
ierr = TSSetInitialTimeStep(ts,0.0,dt);CHKERRQ(ierr);
ierr = TSSetSolution(ts,x);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set runtime options
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Solve nonlinear system
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSolve(ts,x);CHKERRQ(ierr);
wait = PETSC_FALSE;
ierr = PetscOptionsGetBool(NULL,NULL,"-wait",&wait,NULL);CHKERRQ(ierr);
if (wait) {
ierr = PetscSleep(-1);CHKERRQ(ierr);
}
ierr = TSGetTimeStepNumber(ts,&steps);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Free work space. All PETSc objects should be destroyed when they
are no longer needed.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
{
ierr = VecDestroy(&ul);CHKERRQ(ierr);
ierr = VecDestroy(&uh);CHKERRQ(ierr);
}
ierr = MatDestroy(&J);CHKERRQ(ierr);
ierr = MatFDColoringDestroy(&matfdcoloring);CHKERRQ(ierr);
ierr = VecDestroy(&x);CHKERRQ(ierr);
ierr = VecDestroy(&r);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
ierr = PetscFinalize();
PetscFunctionReturn(0);
}