xref: /petsc/src/mat/impls/aij/seq/umfpack/umfpack.c (revision b24902e06ab141841ce6546a773244be2474cd18)

#define PETSCMAT_DLL

/*
   Provides an interface to the UMFPACKv5.1 sparse solver

   This interface uses the "UF_long version" of the UMFPACK API
   (*_dl_* and *_zl_* routines, instead of *_di_* and *_zi_* routines)
   so that UMFPACK can address more than 2Gb of memory on 64 bit
   machines.

   If sizeof(UF_long) == 32 the interface only allocates the memory
   necessary for UMFPACK's working arrays (W, Wi and possibly
   perm_c). If sizeof(UF_long) == 64, in addition to allocating the
   working arrays, the interface also has to re-allocate the matrix
   index arrays (ai and aj, which must be stored as UF_long).

   The interface is implemented for both real and complex
   arithmetic. Complex numbers are assumed to be in packed format,
   which requires UMFPACK >= 4.4.

   We thank Christophe Geuzaine <geuzaine@acm.caltech.edu> for upgrading this interface to the UMFPACKv5.1
*/

#include "src/mat/impls/aij/seq/aij.h"

EXTERN_C_BEGIN
#include "umfpack.h"
EXTERN_C_END

typedef struct {
  void         *Symbolic, *Numeric;
  double       Info[UMFPACK_INFO], Control[UMFPACK_CONTROL],*W;
  UF_long      *Wi,*ai,*aj,*perm_c;
  PetscScalar  *av;
  MatStructure flg;
  PetscTruth   PetscMatOdering;

  /* Flag to clean up UMFPACK objects during Destroy */
  PetscTruth CleanUpUMFPACK;
} Mat_UMFPACK;

#undef __FUNCT__
#define __FUNCT__ "MatDestroy_UMFPACK"
PetscErrorCode MatDestroy_UMFPACK(Mat A)
{
  PetscErrorCode ierr;
  Mat_UMFPACK    *lu=(Mat_UMFPACK*)A->spptr;

  PetscFunctionBegin;
  if (lu->CleanUpUMFPACK) {
#if defined(PETSC_USE_COMPLEX)
    umfpack_zl_free_symbolic(&lu->Symbolic);
    umfpack_zl_free_numeric(&lu->Numeric);
#else
    umfpack_dl_free_symbolic(&lu->Symbolic);
    umfpack_dl_free_numeric(&lu->Numeric);
#endif
    ierr = PetscFree(lu->Wi);CHKERRQ(ierr);
    ierr = PetscFree(lu->W);CHKERRQ(ierr);
    if(sizeof(UF_long) != sizeof(int)){
      ierr = PetscFree(lu->ai);CHKERRQ(ierr);
      ierr = PetscFree(lu->aj);CHKERRQ(ierr);
    }
    if (lu->PetscMatOdering) {
      ierr = PetscFree(lu->perm_c);CHKERRQ(ierr);
    }
  }
  ierr = MatDestroy_SeqAIJ(A);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "MatSolve_UMFPACK"
PetscErrorCode MatSolve_UMFPACK(Mat A,Vec b,Vec x)
{
  Mat_UMFPACK *lu = (Mat_UMFPACK*)A->spptr;
  PetscScalar *av=lu->av,*ba,*xa;
  PetscErrorCode ierr;
  UF_long     *ai=lu->ai,*aj=lu->aj,status;

  PetscFunctionBegin;
  /* solve Ax = b by umfpack_*_wsolve */
  /* ----------------------------------*/

#if defined(PETSC_USE_COMPLEX)
  ierr = VecConjugate(b);
#endif

  ierr = VecGetArray(b,&ba);
  ierr = VecGetArray(x,&xa);

#if defined(PETSC_USE_COMPLEX)
  status = umfpack_zl_wsolve(UMFPACK_At,ai,aj,(double*)av,NULL,(double*)xa,NULL,(double*)ba,NULL,
			     lu->Numeric,lu->Control,lu->Info,lu->Wi,lu->W);
  umfpack_zl_report_info(lu->Control, lu->Info);
  if (status < 0){
    umfpack_zl_report_status(lu->Control, status);
    SETERRQ(PETSC_ERR_LIB,"umfpack_zl_wsolve failed");
  }
#else
  status = umfpack_dl_wsolve(UMFPACK_At,ai,aj,av,xa,ba,
			     lu->Numeric,lu->Control,lu->Info,lu->Wi,lu->W);
  umfpack_dl_report_info(lu->Control, lu->Info);
  if (status < 0){
    umfpack_dl_report_status(lu->Control, status);
    SETERRQ(PETSC_ERR_LIB,"umfpack_dl_wsolve failed");
  }
#endif

  ierr = VecRestoreArray(b,&ba);
  ierr = VecRestoreArray(x,&xa);

#if defined(PETSC_USE_COMPLEX)
  ierr = VecConjugate(b);
  ierr = VecConjugate(x);
#endif

  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "MatLUFactorNumeric_UMFPACK"
PetscErrorCode MatLUFactorNumeric_UMFPACK(Mat A,MatFactorInfo *info,Mat *F)
{
  Mat_UMFPACK *lu=(Mat_UMFPACK*)(*F)->spptr;
  PetscErrorCode ierr;
  UF_long     *ai=lu->ai,*aj=lu->aj,m=A->rmap.n,status;
  PetscScalar *av=lu->av;

  PetscFunctionBegin;
  /* numeric factorization of A' */
  /* ----------------------------*/

#if defined(PETSC_USE_COMPLEX)
  if (lu->flg == SAME_NONZERO_PATTERN && lu->Numeric){
    umfpack_zl_free_numeric(&lu->Numeric);
  }
  status = umfpack_zl_numeric(ai,aj,(double*)av,NULL,lu->Symbolic,&lu->Numeric,lu->Control,lu->Info);
  if (status < 0) SETERRQ(PETSC_ERR_LIB,"umfpack_zl_numeric failed");
  /* report numeric factorization of A' when Control[PRL] > 3 */
  (void) umfpack_zl_report_numeric(lu->Numeric, lu->Control);
#else
  if (lu->flg == SAME_NONZERO_PATTERN && lu->Numeric){
    umfpack_dl_free_numeric(&lu->Numeric);
  }
  status = umfpack_dl_numeric(ai,aj,av,lu->Symbolic,&lu->Numeric,lu->Control,lu->Info);
  if (status < 0) SETERRQ(PETSC_ERR_LIB,"umfpack_dl_numeric failed");
  /* report numeric factorization of A' when Control[PRL] > 3 */
  (void) umfpack_dl_report_numeric(lu->Numeric, lu->Control);
#endif

  if (lu->flg == DIFFERENT_NONZERO_PATTERN){  /* first numeric factorization */
    /* allocate working space to be used by Solve */
    ierr = PetscMalloc(m * sizeof(UF_long), &lu->Wi);CHKERRQ(ierr);
#if defined(PETSC_USE_COMPLEX)
    ierr = PetscMalloc(2*5*m * sizeof(double), &lu->W);CHKERRQ(ierr);
#else
    ierr = PetscMalloc(5*m * sizeof(double), &lu->W);CHKERRQ(ierr);
#endif
  }

  lu->flg = SAME_NONZERO_PATTERN;
  lu->CleanUpUMFPACK = PETSC_TRUE;
  PetscFunctionReturn(0);
}

/*
   Note the r permutation is ignored
*/
#undef __FUNCT__
#define __FUNCT__ "MatLUFactorSymbolic_UMFPACK"
PetscErrorCode MatLUFactorSymbolic_UMFPACK(Mat A,IS r,IS c,MatFactorInfo *info,Mat *F)
{
  Mat            B;
  Mat_SeqAIJ     *mat=(Mat_SeqAIJ*)A->data;
  Mat_UMFPACK    *lu = (Mat_UMFPACK*)((*F)->spptr);
  PetscErrorCode ierr;
  int            i,m=A->rmap.n,n=A->cmap.n,*ra,idx;
  UF_long        status;
  PetscScalar    *av=mat->a;

  PetscFunctionBegin;
  if (lu->PetscMatOdering) {
    ierr = ISGetIndices(r,&ra);CHKERRQ(ierr);
    ierr = PetscMalloc(m*sizeof(UF_long),&lu->perm_c);CHKERRQ(ierr);
    /* we cannot simply memcpy on 64 bit archs */
    for(i = 0; i < m; i++) lu->perm_c[i] = ra[i];
    ierr = ISRestoreIndices(r,&ra);CHKERRQ(ierr);
  }

  if(sizeof(UF_long) != sizeof(int)){
    /* we cannot directly use mat->i and mat->j on 64 bit archs */
    ierr = PetscMalloc((m+1)*sizeof(UF_long),&lu->ai);CHKERRQ(ierr);
    ierr = PetscMalloc(mat->nz*sizeof(UF_long),&lu->aj);CHKERRQ(ierr);
    for(i = 0; i < m + 1; i++) lu->ai[i] = mat->i[i];
    for(i = 0; i < mat->nz; i++) lu->aj[i] = mat->j[i];
  }
  else{
    lu->ai = (UF_long*)mat->i;
    lu->aj = (UF_long*)mat->j;
  }

  /* print the control parameters */
#if defined(PETSC_USE_COMPLEX)
  if(lu->Control[UMFPACK_PRL] > 1) umfpack_zl_report_control(lu->Control);
#else
  if(lu->Control[UMFPACK_PRL] > 1) umfpack_dl_report_control(lu->Control);
#endif

  /* symbolic factorization of A' */
  /* ---------------------------------------------------------------------- */
#if defined(PETSC_USE_COMPLEX)
  if (lu->PetscMatOdering) { /* use Petsc row ordering */
    status = umfpack_zl_qsymbolic(n,m,lu->ai,lu->aj,(double*)av,NULL,
				  lu->perm_c,&lu->Symbolic,lu->Control,lu->Info);
  } else { /* use Umfpack col ordering */
    status = umfpack_zl_symbolic(n,m,lu->ai,lu->aj,(double*)av,NULL,
				 &lu->Symbolic,lu->Control,lu->Info);
  }
  if (status < 0){
    umfpack_zl_report_info(lu->Control, lu->Info);
    umfpack_zl_report_status(lu->Control, status);
    SETERRQ(PETSC_ERR_LIB,"umfpack_dl_symbolic failed");
  }
  /* report sumbolic factorization of A' when Control[PRL] > 3 */
  (void) umfpack_zl_report_symbolic(lu->Symbolic, lu->Control);
#else
  if (lu->PetscMatOdering) { /* use Petsc row ordering */
    status = umfpack_dl_qsymbolic(n,m,lu->ai,lu->aj,av,
				  lu->perm_c,&lu->Symbolic,lu->Control,lu->Info);
  } else { /* use Umfpack col ordering */
    status = umfpack_dl_symbolic(n,m,lu->ai,lu->aj,av,
				 &lu->Symbolic,lu->Control,lu->Info);
  }
  if (status < 0){
    umfpack_dl_report_info(lu->Control, lu->Info);
    umfpack_dl_report_status(lu->Control, status);
    SETERRQ(PETSC_ERR_LIB,"umfpack_dl_symbolic failed");
  }
  /* report sumbolic factorization of A' when Control[PRL] > 3 */
  (void) umfpack_dl_report_symbolic(lu->Symbolic, lu->Control);
#endif

  lu->flg = DIFFERENT_NONZERO_PATTERN;
  lu->av  = av;
  lu->CleanUpUMFPACK = PETSC_TRUE;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "MatGetFactor_seqaij_umfpack"
PetscErrorCode MatGetFactor_seqaij_umfpack(Mat A,Mat *F)
{
  Mat            B;
  Mat_SeqAIJ     *mat=(Mat_SeqAIJ*)A->data;
  Mat_UMFPACK    *lu;
  PetscErrorCode ierr;
  int            i,m=A->rmap.n,n=A->cmap.n,*ra,idx;
  UF_long        status;

  PetscScalar    *av=mat->a;
  const char     *strategy[]={"AUTO","UNSYMMETRIC","SYMMETRIC","2BY2"},
                 *scale[]={"NONE","SUM","MAX"};
  PetscTruth     flg;

  PetscFunctionBegin;
  /* Create the factorization matrix F */
  ierr = MatCreate(((PetscObject)A)->comm,&B);CHKERRQ(ierr);
  ierr = MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,m,n);CHKERRQ(ierr);
  ierr = MatSetType(B,((PetscObject)A)->type_name);CHKERRQ(ierr);
  ierr = MatSeqAIJSetPreallocation(B,0,PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscNewLog(B,Mat_UMFPACK,&lu);CHKERRQ(ierr);
  B->spptr                 = lu;
  B->ops->lufactornumeric  = MatLUFactorNumeric_UMFPACK;
  B->ops->lufactorsymbolic = MatLUFactorSymbolic_UMFPACK;
  B->ops->solve            = MatSolve_UMFPACK;
  B->ops->destroy          = MatDestroy_UMFPACK;
  B->factor                = FACTOR_LU;
  B->assembled             = PETSC_TRUE;  /* required by -ksp_view */


  /* initializations */
  /* ------------------------------------------------*/
  /* get the default control parameters */
#if defined(PETSC_USE_COMPLEX)
  umfpack_zl_defaults(lu->Control);
#else
  umfpack_dl_defaults(lu->Control);
#endif
  lu->perm_c = PETSC_NULL;  /* use defaul UMFPACK col permutation */
  lu->Control[UMFPACK_IRSTEP] = 0; /* max num of iterative refinement steps to attempt */

  ierr = PetscOptionsBegin(((PetscObject)A)->comm,((PetscObject)A)->prefix,"UMFPACK Options","Mat");CHKERRQ(ierr);
  /* Control parameters used by reporting routiones */
  ierr = PetscOptionsReal("-mat_umfpack_prl","Control[UMFPACK_PRL]","None",lu->Control[UMFPACK_PRL],&lu->Control[UMFPACK_PRL],PETSC_NULL);CHKERRQ(ierr);

  /* Control parameters for symbolic factorization */
  ierr = PetscOptionsEList("-mat_umfpack_strategy","ordering and pivoting strategy","None",strategy,4,strategy[0],&idx,&flg);CHKERRQ(ierr);
  if (flg) {
    switch (idx){
    case 0: lu->Control[UMFPACK_STRATEGY] = UMFPACK_STRATEGY_AUTO; break;
    case 1: lu->Control[UMFPACK_STRATEGY] = UMFPACK_STRATEGY_UNSYMMETRIC; break;
    case 2: lu->Control[UMFPACK_STRATEGY] = UMFPACK_STRATEGY_SYMMETRIC; break;
    case 3: lu->Control[UMFPACK_STRATEGY] = UMFPACK_STRATEGY_2BY2; break;
    }
  }
  ierr = PetscOptionsReal("-mat_umfpack_dense_col","Control[UMFPACK_DENSE_COL]","None",lu->Control[UMFPACK_DENSE_COL],&lu->Control[UMFPACK_DENSE_COL],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_dense_row","Control[UMFPACK_DENSE_ROW]","None",lu->Control[UMFPACK_DENSE_ROW],&lu->Control[UMFPACK_DENSE_ROW],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_amd_dense","Control[UMFPACK_AMD_DENSE]","None",lu->Control[UMFPACK_AMD_DENSE],&lu->Control[UMFPACK_AMD_DENSE],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_block_size","Control[UMFPACK_BLOCK_SIZE]","None",lu->Control[UMFPACK_BLOCK_SIZE],&lu->Control[UMFPACK_BLOCK_SIZE],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_2by2_tolerance","Control[UMFPACK_2BY2_TOLERANCE]","None",lu->Control[UMFPACK_2BY2_TOLERANCE],&lu->Control[UMFPACK_2BY2_TOLERANCE],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_fixq","Control[UMFPACK_FIXQ]","None",lu->Control[UMFPACK_FIXQ],&lu->Control[UMFPACK_FIXQ],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_aggressive","Control[UMFPACK_AGGRESSIVE]","None",lu->Control[UMFPACK_AGGRESSIVE],&lu->Control[UMFPACK_AGGRESSIVE],PETSC_NULL);CHKERRQ(ierr);

  /* Control parameters used by numeric factorization */
  ierr = PetscOptionsReal("-mat_umfpack_pivot_tolerance","Control[UMFPACK_PIVOT_TOLERANCE]","None",lu->Control[UMFPACK_PIVOT_TOLERANCE],&lu->Control[UMFPACK_PIVOT_TOLERANCE],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_sym_pivot_tolerance","Control[UMFPACK_SYM_PIVOT_TOLERANCE]","None",lu->Control[UMFPACK_SYM_PIVOT_TOLERANCE],&lu->Control[UMFPACK_SYM_PIVOT_TOLERANCE],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEList("-mat_umfpack_scale","Control[UMFPACK_SCALE]","None",scale,3,scale[0],&idx,&flg);CHKERRQ(ierr);
  if (flg) {
    switch (idx){
    case 0: lu->Control[UMFPACK_SCALE] = UMFPACK_SCALE_NONE; break;
    case 1: lu->Control[UMFPACK_SCALE] = UMFPACK_SCALE_SUM; break;
    case 2: lu->Control[UMFPACK_SCALE] = UMFPACK_SCALE_MAX; break;
    }
  }
  ierr = PetscOptionsReal("-mat_umfpack_alloc_init","Control[UMFPACK_ALLOC_INIT]","None",lu->Control[UMFPACK_ALLOC_INIT],&lu->Control[UMFPACK_ALLOC_INIT],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_front_alloc_init","Control[UMFPACK_FRONT_ALLOC_INIT]","None",lu->Control[UMFPACK_FRONT_ALLOC_INIT],&lu->Control[UMFPACK_ALLOC_INIT],PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_umfpack_droptol","Control[UMFPACK_DROPTOL]","None",lu->Control[UMFPACK_DROPTOL],&lu->Control[UMFPACK_DROPTOL],PETSC_NULL);CHKERRQ(ierr);

  /* Control parameters used by solve */
  ierr = PetscOptionsReal("-mat_umfpack_irstep","Control[UMFPACK_IRSTEP]","None",lu->Control[UMFPACK_IRSTEP],&lu->Control[UMFPACK_IRSTEP],PETSC_NULL);CHKERRQ(ierr);

  /* use Petsc mat ordering (note: size is for the transpose, and PETSc r = Umfpack perm_c) */
  ierr = PetscOptionsHasName(PETSC_NULL,"-pc_factor_mat_ordering_type",&lu->PetscMatOdering);CHKERRQ(ierr);
  PetscOptionsEnd();
  *F = B;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "MatFactorInfo_UMFPACK"
PetscErrorCode MatFactorInfo_UMFPACK(Mat A,PetscViewer viewer)
{
  Mat_UMFPACK    *lu= (Mat_UMFPACK*)A->spptr;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  /* check if matrix is UMFPACK type */
  if (A->ops->solve != MatSolve_UMFPACK) PetscFunctionReturn(0);

  ierr = PetscViewerASCIIPrintf(viewer,"UMFPACK run parameters:\n");CHKERRQ(ierr);
  /* Control parameters used by reporting routiones */
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_PRL]: %g\n",lu->Control[UMFPACK_PRL]);CHKERRQ(ierr);

  /* Control parameters used by symbolic factorization */
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_STRATEGY]: %g\n",lu->Control[UMFPACK_STRATEGY]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_DENSE_COL]: %g\n",lu->Control[UMFPACK_DENSE_COL]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_DENSE_ROW]: %g\n",lu->Control[UMFPACK_DENSE_ROW]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_AMD_DENSE]: %g\n",lu->Control[UMFPACK_AMD_DENSE]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_BLOCK_SIZE]: %g\n",lu->Control[UMFPACK_BLOCK_SIZE]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_2BY2_TOLERANCE]: %g\n",lu->Control[UMFPACK_2BY2_TOLERANCE]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_FIXQ]: %g\n",lu->Control[UMFPACK_FIXQ]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_AGGRESSIVE]: %g\n",lu->Control[UMFPACK_AGGRESSIVE]);CHKERRQ(ierr);

  /* Control parameters used by numeric factorization */
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_PIVOT_TOLERANCE]: %g\n",lu->Control[UMFPACK_PIVOT_TOLERANCE]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_SYM_PIVOT_TOLERANCE]: %g\n",lu->Control[UMFPACK_SYM_PIVOT_TOLERANCE]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_SCALE]: %g\n",lu->Control[UMFPACK_SCALE]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_ALLOC_INIT]: %g\n",lu->Control[UMFPACK_ALLOC_INIT]);CHKERRQ(ierr);
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_DROPTOL]: %g\n",lu->Control[UMFPACK_DROPTOL]);CHKERRQ(ierr);

  /* Control parameters used by solve */
  ierr = PetscViewerASCIIPrintf(viewer,"  Control[UMFPACK_IRSTEP]: %g\n",lu->Control[UMFPACK_IRSTEP]);CHKERRQ(ierr);

  /* mat ordering */
  if(!lu->PetscMatOdering) ierr = PetscViewerASCIIPrintf(viewer,"  UMFPACK default matrix ordering is used (not the PETSc matrix ordering) \n");CHKERRQ(ierr);

  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "MatView_UMFPACK"
PetscErrorCode MatView_UMFPACK(Mat A,PetscViewer viewer)
{
  PetscErrorCode    ierr;
  PetscTruth        iascii;
  PetscViewerFormat format;
  Mat_UMFPACK       *lu=(Mat_UMFPACK*)(A->spptr);

  PetscFunctionBegin;
  ierr = MatView_SeqAIJ(A,viewer);CHKERRQ(ierr);

  ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
  if (iascii) {
    ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
    if (format == PETSC_VIEWER_ASCII_INFO) {
      ierr = MatFactorInfo_UMFPACK(A,viewer);CHKERRQ(ierr);
    }
  }
  PetscFunctionReturn(0);
}

/*MC
  MATUMFPACK - MATUMFPACK = "umfpack" - A matrix type providing direct solvers (LU) for sequential matrices
  via the external package UMFPACK.

  If UMFPACK is installed (see the manual for
  instructions on how to declare the existence of external packages),
  a matrix type can be constructed which invokes UMFPACK solvers.
  After calling MatCreate(...,A), simply call MatSetType(A,UMFPACK).

  This matrix inherits from MATSEQAIJ.  As a result, MatSeqAIJSetPreallocation is
  supported for this matrix type.  One can also call MatConvert for an inplace conversion to or from
  the MATSEQAIJ type without data copy.

  Consult UMFPACK documentation for more information about the Control parameters
  which correspond to the options database keys below.

  Options Database Keys:
+ -mat_type umfpack - sets the matrix type to "umfpack" during a call to MatSetFromOptions()
. -mat_umfpack_prl - UMFPACK print level: Control[UMFPACK_PRL]
. -mat_umfpack_dense_col <alpha_c> - UMFPACK dense column threshold: Control[UMFPACK_DENSE_COL]
. -mat_umfpack_block_size <bs> - UMFPACK block size for BLAS-Level 3 calls: Control[UMFPACK_BLOCK_SIZE]
. -mat_umfpack_pivot_tolerance <delta> - UMFPACK partial pivot tolerance: Control[UMFPACK_PIVOT_TOLERANCE]
. -mat_umfpack_alloc_init <delta> - UMFPACK factorized matrix allocation modifier: Control[UMFPACK_ALLOC_INIT]
- -mat_umfpack_irstep <maxit> - UMFPACK maximum number of iterative refinement steps: Control[UMFPACK_IRSTEP]

   Level: beginner

.seealso: PCLU
M*/