int main(int argc,char **argv)
{
PetscErrorCode ierr;
DS ds;
PetscScalar *A;
PetscInt i,j,n=10,ld;
PetscViewer viewer;
PetscBool verbose;
SlepcInitialize(&argc,&argv,(char*)0,help);
ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Compute symmetric matrix exponential - dimension %D.\n",n);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-verbose",&verbose);CHKERRQ(ierr);
/* Create DS object */
ierr = DSCreate(PETSC_COMM_WORLD,&ds);CHKERRQ(ierr);
ierr = DSSetType(ds,DSHEP);CHKERRQ(ierr);
ierr = DSSetFromOptions(ds);CHKERRQ(ierr);
ld = n+2; /* test leading dimension larger than n */
ierr = DSAllocate(ds,ld);CHKERRQ(ierr);
ierr = DSSetDimensions(ds,n,0,0,0);CHKERRQ(ierr);
/* Set up viewer */
ierr = PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);CHKERRQ(ierr);
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
if (verbose) {
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
}
/* Fill with a symmetric Toeplitz matrix */
ierr = DSGetArray(ds,DS_MAT_A,&A);CHKERRQ(ierr);
for (i=0;i<n;i++) A[i+i*ld]=2.0;
for (j=1;j<3;j++) {
for (i=0;i<n-j;i++) { A[i+(i+j)*ld]=1.0; A[(i+j)+i*ld]=1.0; }
}
ierr = DSRestoreArray(ds,DS_MAT_A,&A);CHKERRQ(ierr);
ierr = DSSetState(ds,DS_STATE_RAW);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Matrix A - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Compute matrix exponential */
ierr = DSComputeFunction(ds,SLEPC_FUNCTION_EXP);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Computed f(A) - - - - - - -\n");CHKERRQ(ierr);
ierr = DSViewMat(ds,viewer,DS_MAT_F);CHKERRQ(ierr);
}
ierr = DSDestroy(&ds);CHKERRQ(ierr);
ierr = SlepcFinalize();
return 0;
}
/*@
EPSSetDS - Associates a direct solver object to the eigensolver.
Collective on EPS
Input Parameters:
+ eps - eigensolver context obtained from EPSCreate()
- ds - the direct solver object
Note:
Use EPSGetDS() to retrieve the direct solver context (for example,
to free it at the end of the computations).
Level: advanced
.seealso: EPSGetDS()
@*/
PetscErrorCode EPSSetDS(EPS eps,DS ds)
{
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(eps,EPS_CLASSID,1);
PetscValidHeaderSpecific(ds,DS_CLASSID,2);
PetscCheckSameComm(eps,1,ds,2);
ierr = PetscObjectReference((PetscObject)ds);
CHKERRQ(ierr);
ierr = DSDestroy(&eps->ds);
CHKERRQ(ierr);
eps->ds = ds;
ierr = PetscLogObjectParent((PetscObject)eps,(PetscObject)eps->ds);
CHKERRQ(ierr);
PetscFunctionReturn(0);
}
/*@C
EPSDestroy - Destroys the EPS context.
Collective on EPS
Input Parameter:
. eps - eigensolver context obtained from EPSCreate()
Level: beginner
.seealso: EPSCreate(), EPSSetUp(), EPSSolve()
@*/
PetscErrorCode EPSDestroy(EPS *eps)
{
PetscErrorCode ierr;
PetscFunctionBegin;
if (!*eps) PetscFunctionReturn(0);
PetscValidHeaderSpecific(*eps,EPS_CLASSID,1);
if (--((PetscObject)(*eps))->refct > 0) {
*eps = 0;
PetscFunctionReturn(0);
}
ierr = EPSReset(*eps);
CHKERRQ(ierr);
if ((*eps)->ops->destroy) {
ierr = (*(*eps)->ops->destroy)(*eps);
CHKERRQ(ierr);
}
ierr = STDestroy(&(*eps)->st);
CHKERRQ(ierr);
ierr = RGDestroy(&(*eps)->rg);
CHKERRQ(ierr);
ierr = DSDestroy(&(*eps)->ds);
CHKERRQ(ierr);
ierr = PetscRandomDestroy(&(*eps)->rand);
CHKERRQ(ierr);
ierr = PetscFree((*eps)->sc);
CHKERRQ(ierr);
/* just in case the initial vectors have not been used */
ierr = SlepcBasisDestroy_Private(&(*eps)->nds,&(*eps)->defl);
CHKERRQ(ierr);
ierr = SlepcBasisDestroy_Private(&(*eps)->nini,&(*eps)->IS);
CHKERRQ(ierr);
if ((*eps)->convergeddestroy) {
ierr = (*(*eps)->convergeddestroy)((*eps)->convergedctx);
CHKERRQ(ierr);
}
ierr = EPSMonitorCancel(*eps);
CHKERRQ(ierr);
ierr = PetscHeaderDestroy(eps);
CHKERRQ(ierr);
PetscFunctionReturn(0);
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
DS ds;
SlepcSC sc;
PetscScalar *A,*B,*wr,*wi;
PetscReal re,im;
PetscInt i,j,n=10,ld;
PetscViewer viewer;
PetscBool verbose;
SlepcInitialize(&argc,&argv,(char*)0,help);
ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type GNHEP - dimension %D.\n",n);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-verbose",&verbose);CHKERRQ(ierr);
/* Create DS object */
ierr = DSCreate(PETSC_COMM_WORLD,&ds);CHKERRQ(ierr);
ierr = DSSetType(ds,DSGNHEP);CHKERRQ(ierr);
ierr = DSSetFromOptions(ds);CHKERRQ(ierr);
ld = n+2; /* test leading dimension larger than n */
ierr = DSAllocate(ds,ld);CHKERRQ(ierr);
ierr = DSSetDimensions(ds,n,0,0,0);CHKERRQ(ierr);
/* Set up viewer */
ierr = PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);CHKERRQ(ierr);
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
if (verbose) {
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
}
/* Fill A with Grcar matrix */
ierr = DSGetArray(ds,DS_MAT_A,&A);CHKERRQ(ierr);
ierr = PetscMemzero(A,sizeof(PetscScalar)*ld*n);CHKERRQ(ierr);
for (i=1;i<n;i++) A[i+(i-1)*ld]=-1.0;
for (j=0;j<4;j++) {
for (i=0;i<n-j;i++) A[i+(i+j)*ld]=1.0;
}
ierr = DSRestoreArray(ds,DS_MAT_A,&A);CHKERRQ(ierr);
/* Fill B with an identity matrix */
ierr = DSGetArray(ds,DS_MAT_B,&B);CHKERRQ(ierr);
ierr = PetscMemzero(B,sizeof(PetscScalar)*ld*n);CHKERRQ(ierr);
for (i=0;i<n;i++) B[i+i*ld]=1.0;
ierr = DSRestoreArray(ds,DS_MAT_B,&B);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Solve */
ierr = PetscMalloc2(n,&wr,n,&wi);CHKERRQ(ierr);
ierr = DSGetSlepcSC(ds,&sc);CHKERRQ(ierr);
sc->comparison = SlepcCompareLargestMagnitude;
sc->comparisonctx = NULL;
sc->map = NULL;
sc->mapobj = NULL;
ierr = DSSolve(ds,wr,wi);CHKERRQ(ierr);
ierr = DSSort(ds,wr,wi,NULL,NULL,NULL);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Print eigenvalues */
ierr = PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n",n);CHKERRQ(ierr);
for (i=0;i<n;i++) {
#if defined(PETSC_USE_COMPLEX)
re = PetscRealPart(wr[i]);
im = PetscImaginaryPart(wr[i]);
#else
re = wr[i];
im = wi[i];
#endif
if (PetscAbs(im)<1e-10) {
ierr = PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re);CHKERRQ(ierr);
} else {
ierr = PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im);CHKERRQ(ierr);
}
}
ierr = PetscFree2(wr,wi);CHKERRQ(ierr);
ierr = DSDestroy(&ds);CHKERRQ(ierr);
ierr = SlepcFinalize();
return 0;
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
DS ds;
FN f1,f2,f3,funs[3];
PetscScalar *Id,*A,*B,*wr,*wi,coeffs[2];
PetscReal tau=0.001,h,a=20,xi,re,im;
PetscInt i,n=10,ld,nev;
PetscViewer viewer;
PetscBool verbose;
SlepcInitialize(&argc,&argv,(char*)0,help);
ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetReal(NULL,"-tau",&tau,NULL);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NEP - dimension %D, tau=%g.\n",n,(double)tau);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-verbose",&verbose);CHKERRQ(ierr);
/* Create DS object */
ierr = DSCreate(PETSC_COMM_WORLD,&ds);CHKERRQ(ierr);
ierr = DSSetType(ds,DSNEP);CHKERRQ(ierr);
ierr = DSSetFromOptions(ds);CHKERRQ(ierr);
/* Set functions (prior to DSAllocate) */
ierr = FNCreate(PETSC_COMM_WORLD,&f1);CHKERRQ(ierr);
ierr = FNSetType(f1,FNRATIONAL);CHKERRQ(ierr);
coeffs[0] = -1.0; coeffs[1] = 0.0;
ierr = FNSetParameters(f1,2,coeffs,0,NULL);CHKERRQ(ierr);
ierr = FNCreate(PETSC_COMM_WORLD,&f2);CHKERRQ(ierr);
ierr = FNSetType(f2,FNRATIONAL);CHKERRQ(ierr);
coeffs[0] = 1.0;
ierr = FNSetParameters(f2,1,coeffs,0,NULL);CHKERRQ(ierr);
ierr = FNCreate(PETSC_COMM_WORLD,&f3);CHKERRQ(ierr);
ierr = FNSetType(f3,FNEXP);CHKERRQ(ierr);
coeffs[0] = -tau;
ierr = FNSetParameters(f3,1,coeffs,0,NULL);CHKERRQ(ierr);
funs[0] = f1;
funs[1] = f2;
funs[2] = f3;
ierr = DSSetFN(ds,3,funs);CHKERRQ(ierr);
/* Set dimensions */
ld = n+2; /* test leading dimension larger than n */
ierr = DSAllocate(ds,ld);CHKERRQ(ierr);
ierr = DSSetDimensions(ds,n,0,0,0);CHKERRQ(ierr);
/* Set up viewer */
ierr = PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);CHKERRQ(ierr);
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
if (verbose) {
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
}
/* Fill matrices */
ierr = DSGetArray(ds,DS_MAT_E0,&Id);CHKERRQ(ierr);
for (i=0;i<n;i++) Id[i+i*ld]=1.0;
ierr = DSRestoreArray(ds,DS_MAT_E0,&Id);CHKERRQ(ierr);
h = PETSC_PI/(PetscReal)(n+1);
ierr = DSGetArray(ds,DS_MAT_E1,&A);CHKERRQ(ierr);
for (i=0;i<n;i++) A[i+i*ld]=-2.0/(h*h)+a;
for (i=1;i<n;i++) {
A[i+(i-1)*ld]=1.0/(h*h);
A[(i-1)+i*ld]=1.0/(h*h);
}
ierr = DSRestoreArray(ds,DS_MAT_E1,&A);CHKERRQ(ierr);
ierr = DSGetArray(ds,DS_MAT_E2,&B);CHKERRQ(ierr);
for (i=0;i<n;i++) {
xi = (i+1)*h;
B[i+i*ld] = -4.1+xi*(1.0-PetscExpReal(xi-PETSC_PI));
}
ierr = DSRestoreArray(ds,DS_MAT_E2,&B);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Solve */
ierr = PetscMalloc2(n,&wr,n,&wi);CHKERRQ(ierr);
ierr = DSSolve(ds,wr,wi);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Print first eigenvalue */
ierr = PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalue =\n",n);CHKERRQ(ierr);
nev = 1;
for (i=0;i<nev;i++) {
#if defined(PETSC_USE_COMPLEX)
re = PetscRealPart(wr[i]);
im = PetscImaginaryPart(wr[i]);
#else
re = wr[i];
im = wi[i];
#endif
if (PetscAbs(im)<1e-10) {
ierr = PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re);CHKERRQ(ierr);
} else {
ierr = PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im);CHKERRQ(ierr);
}
}
ierr = PetscFree2(wr,wi);CHKERRQ(ierr);
ierr = FNDestroy(&f1);CHKERRQ(ierr);
ierr = FNDestroy(&f2);CHKERRQ(ierr);
ierr = FNDestroy(&f3);CHKERRQ(ierr);
ierr = DSDestroy(&ds);CHKERRQ(ierr);
ierr = SlepcFinalize();
return 0;
}
void
plotter_done(void)
{
PLOTTER pl;
MFILE *f;
char *fname;
static struct dstring *xplot_cmd_buff=NULL;
if(plotter_ix>0) {
if(xplot_all_files) {
xplot_cmd_buff=DSNew();
DSAppendString(xplot_cmd_buff,"xplot");
DSAppendString(xplot_cmd_buff," ");
if(xplot_args!=NULL) {
DSAppendString(xplot_cmd_buff,xplot_args);
DSAppendString(xplot_cmd_buff," ");
}
}
}
for (pl = 0; pl <= plotter_ix; ++pl) {
struct plotter_info *ppi = &pplotters[pl];
if ((f = ppi->fplot) == NULL)
continue;
/* Write the plotter header if not already written */
if(!ppi->header_done)
WritePlotHeader(pl);
if (!ignore_non_comp ||
((ppi->p2plast != NULL) && (ConnComplete(ppi->p2plast->ptp)))) {
Mfprintf(f,"go\n");
Mfclose(f);
} else {
fname = ppi->p2plast->tsg_plotfile;
if (debug)
fprintf(stderr,"Removing incomplete plot file '%s'\n",
fname);
Mfclose(f);
if (unlink(fname) != 0)
perror(fname);
}
if(xplot_all_files){
if(output_file_dir!=NULL) {
DSAppendString(xplot_cmd_buff,output_file_dir);
DSAppendString(xplot_cmd_buff,"/");
}
DSAppendString(xplot_cmd_buff,ppi->filename);
DSAppendString(xplot_cmd_buff," ");
}
}
if(plotter_ix>0) {
if(xplot_all_files) {
fprintf(stdout,"%s\n",DSVal(xplot_cmd_buff));
system(DSVal(xplot_cmd_buff));
DSDestroy(&xplot_cmd_buff);
}
}
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
DS ds;
SlepcSC sc;
PetscReal *T,*s,re,im;
PetscScalar *eigr,*eigi;
PetscInt i,n=10,l=2,k=5,ld;
PetscViewer viewer;
PetscBool verbose;
SlepcInitialize(&argc,&argv,(char*)0,help);
ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type GHIEP with compact storage - dimension %D.\n",n);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-l",&l,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-k",&k,NULL);CHKERRQ(ierr);
if (l>n || k>n || l>k) SETERRQ(PETSC_COMM_WORLD,1,"Wrong value of dimensions");
ierr = PetscOptionsHasName(NULL,"-verbose",&verbose);CHKERRQ(ierr);
/* Create DS object */
ierr = DSCreate(PETSC_COMM_WORLD,&ds);CHKERRQ(ierr);
ierr = DSSetType(ds,DSGHIEP);CHKERRQ(ierr);
ierr = DSSetFromOptions(ds);CHKERRQ(ierr);
ld = n+2; /* test leading dimension larger than n */
ierr = DSAllocate(ds,ld);CHKERRQ(ierr);
ierr = DSSetDimensions(ds,n,0,l,k);CHKERRQ(ierr);
ierr = DSSetCompact(ds,PETSC_TRUE);CHKERRQ(ierr);
/* Set up viewer */
ierr = PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);CHKERRQ(ierr);
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
if (verbose) {
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
}
/* Fill arrow-tridiagonal matrix */
ierr = DSGetArrayReal(ds,DS_MAT_T,&T);CHKERRQ(ierr);
ierr = DSGetArrayReal(ds,DS_MAT_D,&s);CHKERRQ(ierr);
for (i=0;i<n;i++) T[i] = (PetscReal)(i+1);
for (i=k;i<n-1;i++) T[i+ld] = 1.0;
for (i=l;i<k;i++) T[i+2*ld] = 1.0;
T[2*ld+l+1] = -7; T[ld+k+1] = -7;
/* Signature matrix */
for (i=0;i<n;i++) s[i] = 1.0;
s[l+1] = -1.0;
s[k+1] = -1.0;
ierr = DSRestoreArrayReal(ds,DS_MAT_T,&T);CHKERRQ(ierr);
ierr = DSRestoreArrayReal(ds,DS_MAT_D,&s);CHKERRQ(ierr);
if (l==0 && k==0) {
ierr = DSSetState(ds,DS_STATE_INTERMEDIATE);CHKERRQ(ierr);
} else {
ierr = DSSetState(ds,DS_STATE_RAW);CHKERRQ(ierr);
}
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Solve */
ierr = PetscCalloc2(n,&eigr,n,&eigi);CHKERRQ(ierr);
ierr = DSGetSlepcSC(ds,&sc);CHKERRQ(ierr);
sc->comparison = SlepcCompareLargestMagnitude;
sc->comparisonctx = NULL;
sc->map = NULL;
sc->mapobj = NULL;
ierr = DSSolve(ds,eigr,eigi);CHKERRQ(ierr);
ierr = DSSort(ds,eigr,eigi,NULL,NULL,NULL);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Print eigenvalues */
ierr = PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n",n);CHKERRQ(ierr);
for (i=0;i<n;i++) {
#if defined(PETSC_USE_COMPLEX)
re = PetscRealPart(eigr[i]);
im = PetscImaginaryPart(eigr[i]);
#else
re = eigr[i];
im = eigi[i];
#endif
if (PetscAbs(im)<1e-10) {
ierr = PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re);CHKERRQ(ierr);
} else {
ierr = PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im);CHKERRQ(ierr);
}
}
ierr = PetscFree2(eigr,eigi);CHKERRQ(ierr);
ierr = DSDestroy(&ds);CHKERRQ(ierr);
ierr = SlepcFinalize();
return 0;
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
DS ds;
SlepcSC sc;
PetscScalar *A,*eig;
PetscInt i,j,n,ld,bs,maxbw=3,nblks=8;
PetscViewer viewer;
PetscBool verbose;
SlepcInitialize(&argc,&argv,(char*)0,help);
ierr = PetscOptionsGetInt(NULL,"-maxbw",&maxbw,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-nblks",&nblks,NULL);CHKERRQ(ierr);
n = maxbw*nblks;
bs = maxbw;
ierr = PetscPrintf(PETSC_COMM_WORLD,"Solve a block HEP Dense System - dimension %D (bandwidth=%D, blocks=%D).\n",n,maxbw,nblks);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-verbose",&verbose);CHKERRQ(ierr);
/* Create DS object */
ierr = DSCreate(PETSC_COMM_WORLD,&ds);CHKERRQ(ierr);
ierr = DSSetType(ds,DSHEP);CHKERRQ(ierr);
ierr = DSSetMethod(ds,3);CHKERRQ(ierr); /* Select block divide-and-conquer */
ierr = DSSetBlockSize(ds,bs);CHKERRQ(ierr);
ierr = DSSetFromOptions(ds);CHKERRQ(ierr);
ld = n;
ierr = DSAllocate(ds,ld);CHKERRQ(ierr);
ierr = DSSetDimensions(ds,n,0,0,0);CHKERRQ(ierr);
/* Set up viewer */
ierr = PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);CHKERRQ(ierr);
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr);
if (verbose) {
ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
}
/* Fill with a symmetric band Toeplitz matrix */
ierr = DSGetArray(ds,DS_MAT_A,&A);CHKERRQ(ierr);
for (i=0;i<n;i++) A[i+i*ld]=2.0;
for (j=1;j<=bs;j++) {
for (i=0;i<n-j;i++) { A[i+(i+j)*ld]=1.0; A[(i+j)+i*ld]=1.0; }
}
ierr = DSRestoreArray(ds,DS_MAT_A,&A);CHKERRQ(ierr);
ierr = DSSetState(ds,DS_STATE_RAW);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Solve */
ierr = PetscMalloc1(n,&eig);CHKERRQ(ierr);
ierr = DSGetSlepcSC(ds,&sc);CHKERRQ(ierr);
sc->comparison = SlepcCompareSmallestReal;
sc->comparisonctx = NULL;
sc->map = NULL;
sc->mapobj = NULL;
ierr = DSSolve(ds,eig,NULL);CHKERRQ(ierr);
ierr = DSSort(ds,eig,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
if (verbose) {
ierr = PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");CHKERRQ(ierr);
ierr = DSView(ds,viewer);CHKERRQ(ierr);
}
/* Print eigenvalues */
ierr = PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n",n);CHKERRQ(ierr);
for (i=0;i<n;i++) {
ierr = PetscViewerASCIIPrintf(viewer," %.5f\n",(double)PetscRealPart(eig[i]));CHKERRQ(ierr);
}
ierr = PetscFree(eig);CHKERRQ(ierr);
ierr = DSDestroy(&ds);CHKERRQ(ierr);
ierr = SlepcFinalize();
return 0;
}