#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) {
    umfpack_zl_report_status(lu->Control, status);
    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) {
    umfpack_zl_report_status(lu->Control, status);
    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_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;
  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,MatFactorType ftype,Mat *F) 
{
  Mat            B;
  Mat_UMFPACK    *lu;
  PetscErrorCode ierr;
  int            m=A->rmap.n,n=A->cmap.n,idx;

  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                = MAT_FACTOR_LU;
  B->assembled             = PETSC_TRUE;  /* required by -ksp_view */
  B->preallocated          = PETSC_TRUE;
  
  /* 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;

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

  config/configure.py --download-umfpack to install PETSc to use UMFPACK

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

  Options Database Keys:
+ -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*/