Subversion Repositories slepc-dev

/*

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

   SLEPc - Scalable Library for Eigenvalue Problem Computations

   Copyright (c) 2002-2011, Universitat Politecnica de Valencia, Spain

   This file is part of SLEPc.

   SLEPc is free software: you can redistribute it and/or modify it under  the

   terms of version 3 of the GNU Lesser General Public License as published by

   the Free Software Foundation.

   SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY

   WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS

   FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for

   more details.

   You  should have received a copy of the GNU Lesser General  Public  License

   along with SLEPc. If not, see <http://www.gnu.org/licenses/>.

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

*/

#include <slepc-private/psimpl.h>      /*I "slepcps.h" I*/

#include <slepcblaslapack.h>

#undef __FUNCT__  

#define __FUNCT__ "PSAllocate_GHIEP"

PetscErrorCode PSAllocate_GHIEP(PS ps,PetscInt ld)

{

  PetscErrorCode ierr;

  PetscFunctionBegin;

  ierr = PSAllocateMat_Private(ps,PS_MAT_A);CHKERRQ(ierr);

  ierr = PSAllocateMat_Private(ps,PS_MAT_Q);CHKERRQ(ierr);

  ierr = PSAllocateMatReal_Private(ps,PS_MAT_T);CHKERRQ(ierr);

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "PSView_GHIEP"

PetscErrorCode PSView_GHIEP(PS ps,PetscViewer viewer)

{

  PetscErrorCode    ierr;

  PetscViewerFormat format;

  PetscInt          i,j,r,c;

  PetscReal         value;

  const char        *meth[] = { "LAPACK's _steqr" };

  PetscFunctionBegin;

  ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);

  if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {

    ierr = PetscViewerASCIIPrintf(viewer,"solving the problem with: %s\n",meth[ps->method]);CHKERRQ(ierr);

    PetscFunctionReturn(0);

  }

  if (ps->compact) {

    ierr = PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);CHKERRQ(ierr);

    if (format == PETSC_VIEWER_ASCII_MATLAB) {

      ierr = PetscViewerASCIIPrintf(viewer,"%% Size = %D %D\n",ps->n,ps->n);CHKERRQ(ierr);

      ierr = PetscViewerASCIIPrintf(viewer,"zzz = zeros(%D,3);\n",3*ps->n);CHKERRQ(ierr);

      ierr = PetscViewerASCIIPrintf(viewer,"zzz = [\n");CHKERRQ(ierr);

      for (i=0;i<ps->n;i++) {

        ierr = PetscViewerASCIIPrintf(viewer,"%D %D  %18.16e\n",i+1,i+1,*(ps->rmat[PS_MAT_T]+i));CHKERRQ(ierr);

      }

      for (i=0;i<ps->n-1;i++) {

        r = PetscMax(i+2,ps->k+1);

        c = i+1;

        ierr = PetscViewerASCIIPrintf(viewer,"%D %D  %18.16e\n",r,c,*(ps->rmat[PS_MAT_T]+ps->ld+i));CHKERRQ(ierr);

        ierr = PetscViewerASCIIPrintf(viewer,"%D %D  %18.16e\n",c,r,*(ps->rmat[PS_MAT_T]+ps->ld+i));CHKERRQ(ierr);

      }

      ierr = PetscViewerASCIIPrintf(viewer,"];\n%s = spconvert(zzz);\n",PSMatName[PS_MAT_T]);CHKERRQ(ierr);

    } else {

      for (i=0;i<ps->n;i++) {

        for (j=0;j<ps->n;j++) {

          if (i==j) value = *(ps->rmat[PS_MAT_T]+i);

          else if ((i<ps->k && j==ps->k) || (i==ps->k && j<ps->k)) value = *(ps->rmat[PS_MAT_T]+ps->ld+PetscMin(i,j));

          else if (i==j+1 && i>ps->k) value = *(ps->rmat[PS_MAT_T]+ps->ld+i-1);

          else if (i+1==j && j>ps->k) value = *(ps->rmat[PS_MAT_T]+ps->ld+j-1);

          else value = 0.0;

          ierr = PetscViewerASCIIPrintf(viewer," %18.16e ",value);CHKERRQ(ierr);

        }

        ierr = PetscViewerASCIIPrintf(viewer,"\n");CHKERRQ(ierr);

      }

    }

    ierr = PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);CHKERRQ(ierr);

    ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);

  } else {

    ierr = PSViewMat_Private(ps,viewer,PS_MAT_A);CHKERRQ(ierr);

  }

  if (ps->state>PS_STATE_INTERMEDIATE) {

    ierr = PSViewMat_Private(ps,viewer,PS_MAT_Q);CHKERRQ(ierr);

  }

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "PSVectors_GHIEP"

PetscErrorCode PSVectors_GHIEP(PS ps,PSMatType mat,PetscInt *k,PetscReal *rnorm)

{

  PetscScalar    *Q = ps->mat[PS_MAT_Q];

  PetscInt       ld = ps->ld;

  PetscErrorCode ierr;

  PetscFunctionBegin;

  if (ps->state<PS_STATE_CONDENSED) SETERRQ(((PetscObject)ps)->comm,PETSC_ERR_ORDER,"Must call PSSolve() first");

  switch (mat) {

    case PS_MAT_X:

    case PS_MAT_Y:

      if (k) {

        ierr = PetscMemcpy(ps->mat[mat]+(*k)*ld,Q+(*k)*ld,ld*sizeof(PetscScalar));CHKERRQ(ierr);

      } else {

        ierr = PetscMemcpy(ps->mat[mat],Q,ld*ld*sizeof(PetscScalar));CHKERRQ(ierr);

      }

      if (rnorm) *rnorm = PetscAbsScalar(Q[ps->n-1+(*k)*ld]);

      break;

    case PS_MAT_U:

    case PS_MAT_VT:

      SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not implemented yet");

      break;

    default:

      SETERRQ(((PetscObject)ps)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Invalid mat parameter");

  }

  PetscFunctionReturn(0);

}

#undef __FUNCT__  

#define __FUNCT__ "PSSolve_GHIEP"

PetscErrorCode PSSolve_GHIEP(PS ps,PetscScalar *wr,PetscScalar *wi)

{

#if defined(SLEPC_MISSING_LAPACK_SYTRD) || defined(SLEPC_MISSING_LAPACK_ORGTR) || defined(SLEPC_MISSING_LAPACK_STEQR)

  PetscFunctionBegin;

  SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"SYTRD/ORGTR/STEQR - Lapack routine is unavailable.");

#else

  PetscErrorCode ierr;

  PetscInt       i,j;

  PetscBLASInt   n1,n2,lwork,info,n,ld;

  PetscScalar    *A,*S,*Q,*work,*tau;

  PetscReal      *d,*e;

  PetscFunctionBegin;

  n  = PetscBLASIntCast(ps->n);

  ld = PetscBLASIntCast(ps->ld);

  Q  = ps->mat[PS_MAT_Q];

  d  = ps->rmat[PS_MAT_T];

  e  = ps->rmat[PS_MAT_T]+ld;

  if (ps->compact) {

    n1 = PetscBLASIntCast(ps->k+1);    /* size of leading block, including residuals */

    n2 = PetscBLASIntCast(n-ps->k-1);  /* size of trailing block */

    /* initialize orthogonal matrix */

    ierr = PetscMemzero(Q,ld*ld*sizeof(PetscScalar));CHKERRQ(ierr);

    for (i=0;i<n;i++) Q[i+i*ld] = 1.0;

    if (n==1) { wr[0] = d[0]; PetscFunctionReturn(0); }

    /* reduce to tridiagonal form */

    if (ps->state<PS_STATE_INTERMEDIATE) {

      ierr = PSAllocateMat_Private(ps,PS_MAT_W);CHKERRQ(ierr);

      S = ps->mat[PS_MAT_W];

      ierr = PetscMemzero(S,ld*ld*sizeof(PetscScalar));CHKERRQ(ierr);

      ierr = PSAllocateWork_Private(ps,ld+ld*ld,0,0);CHKERRQ(ierr);

      tau  = ps->work;

      work = ps->work+ld;

      lwork = ld*ld;

      /* Flip matrix S */

      for (i=0;i<n;i++) S[(n-1-i)+(n-1-i)*ld] = d[i];

      for (i=0;i<ps->k;i++) S[(n-1-i)+(n-1-ps->k)*ld] = e[i];

      for (i=ps->k;i<n-1;i++) S[(n-1-i)+(n-1-i-1)*ld] = e[i];

      /* Reduce (2,2)-block of flipped S to tridiagonal form */

      LAPACKsytrd_("L",&n1,S+n2+n2*ld,&ld,d,e,tau,work,&lwork,&info);

      if (info) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in Lapack xSYTRD %d",info);

      /* Flip back diag and subdiag, put them in d and e */

      for (i=0;i<n-1;i++) {

        d[n-i-1] = PetscRealPart(S[i+i*ld]);

        e[n-i-2] = PetscRealPart(S[i+1+i*ld]);

      }

      d[0] = PetscRealPart(S[n-1+(n-1)*ld]);

      /* Compute the orthogonal matrix used for tridiagonalization */

      LAPACKorgtr_("L",&n1,S+n2+n2*ld,&ld,tau,work,&lwork,&info);

      if (info) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in Lapack xORGTR %d",info);

      /* Create full-size Q, flipped back to original order */

      for (i=0;i<n1;i++)

        for (j=0;j<n1;j++)

          Q[i+j*ld] = S[n-i-1+(n-j-1)*ld];

    }

  } else {

    A  = ps->mat[PS_MAT_A];

    if (n==1) { d[0] = PetscRealPart(A[0]); wr[0] = d[0]; Q[0] = 1.0; PetscFunctionReturn(0); }

    if (ps->state<PS_STATE_INTERMEDIATE) {

      /* reduce to tridiagonal form */

      ierr = PetscMemcpy(Q,A,ld*ld*sizeof(PetscScalar));CHKERRQ(ierr);

      ierr = PSAllocateWork_Private(ps,ld+ld*ld,0,0);CHKERRQ(ierr);

      tau  = ps->work;

      work = ps->work+ld;

      lwork = ld*ld;

      LAPACKsytrd_("L",&n,Q,&ld,d,e,tau,work,&lwork,&info);

      if (info) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in Lapack xSYTRD %d",info);

      LAPACKorgtr_("L",&n,Q,&ld,tau,work,&lwork,&info);

      if (info) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in Lapack xORGTR %d",info);

    } else {

      /* initialize orthogonal matrix; copy tridiagonal to d,e */

      ierr = PetscMemzero(Q,ld*ld*sizeof(PetscScalar));CHKERRQ(ierr);

      for (i=0;i<n;i++) Q[i+i*ld] = 1.0;

      for (i=0;i<n;i++) d[i] = PetscRealPart(A[i+i*ld]);

      for (i=0;i<n-1;i++) e[i] = PetscRealPart(A[(i+1)+i*ld]);

    }

  }

  /* Solve the tridiagonal eigenproblem */

  ierr = PSAllocateWork_Private(ps,0,2*ld,0);CHKERRQ(ierr);

  LAPACKsteqr_("V",&n,d,e,Q,&ld,ps->rwork,&info);

  if (info) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in Lapack xSTEQR %d",info);

  for (i=0;i<n;i++) wr[i] = d[i];

  if (ps->compact) {

    ierr = PetscMemzero(e,(n-1)*sizeof(PetscReal));CHKERRQ(ierr);

  } else {

    ierr = PetscMemzero(A,ld*ld*sizeof(PetscScalar));CHKERRQ(ierr);

    for (i=0;i<n;i++) A[i+i*ld] = d[i];

  }

  /* The result is stored in both places (compact and regular) */

  ps->compact = PETSC_TRUE;

  PetscFunctionReturn(0);

#endif

}

#undef __FUNCT__  

#define __FUNCT__ "PSSort_GHIEP"

PetscErrorCode PSSort_GHIEP(PS ps,PetscScalar *wr,PetscScalar *wi,PetscErrorCode (*comp_func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void *comp_ctx)

{

  PetscErrorCode ierr;

  PetscInt       n,l,i,*perm;

  PetscScalar    *A;

  PetscReal      *d;

  PetscFunctionBegin;

  n = ps->n;

  l = ps->l;

  d = ps->rmat[PS_MAT_T];

  ierr = PSAllocateWork_Private(ps,0,0,ps->ld);CHKERRQ(ierr);

  perm = ps->iwork;

  ierr = PSSortEigenvaluesReal_Private(ps,n,l,d,perm,comp_func,comp_ctx);CHKERRQ(ierr);

  for (i=l;i<n;i++) wr[i] = d[perm[i]];

  ierr = PSPermuteColumns_Private(ps,l,n,PS_MAT_Q,perm);CHKERRQ(ierr);

  if (ps->compact) {

    for (i=l;i<n;i++) d[i] = PetscRealPart(wr[i]);

  } else {

    A  = ps->mat[PS_MAT_A];

    for (i=l;i<n;i++) A[i+i*ps->ld] = wr[i];

  }

  PetscFunctionReturn(0);

}

EXTERN_C_BEGIN

#undef __FUNCT__  

#define __FUNCT__ "PSCreate_GHIEP"

PetscErrorCode PSCreate_GHIEP(PS ps)

{

  PetscFunctionBegin;

  ps->ops->allocate      = PSAllocate_GHIEP;

  ps->ops->view          = PSView_GHIEP;

  ps->ops->vectors       = PSVectors_GHIEP;

  ps->ops->solve[0]      = PSSolve_GHIEP;

  ps->ops->sort          = PSSort_GHIEP;

  PetscFunctionReturn(0);

}

EXTERN_C_END