template <typename Entry> int spqr_1colamd // TRUE if OK, FALSE otherwise
(
// inputs, not modified
int ordering, // all available, except 0:fixed and 3:given
// treated as 1:natural
double tol, // only accept singletons above tol
Long bncols, // number of columns of B
cholmod_sparse *A, // m-by-n sparse matrix
// outputs, neither allocated nor defined on input
Long **p_Q1fill, // size n+bncols, fill-reducing
// or natural ordering
Long **p_R1p, // size n1rows+1, R1p [k] = # of nonzeros in kth
// row of R1. NULL if n1cols == 0.
Long **p_P1inv, // size m, singleton row inverse permutation.
// If row i of A is the kth singleton row, then
// P1inv [i] = k. NULL if n1cols is zero.
cholmod_sparse **p_Y, // on output, only the first n-n1cols+1 entries of
// Y->p are defined (if Y is not NULL), where
// Y = [A B] or Y = [A2 B2]. If B is empty and
// there are no column singletons, Y is NULL
Long *p_n1cols, // number of column singletons found
Long *p_n1rows, // number of corresponding rows found
// workspace and parameters
cholmod_common *cc
)
{
Long *Q1fill, *Degree, *Qrows, *W, *Winv, *ATp, *ATj, *R1p, *P1inv, *Yp,
*Ap, *Ai, *Work ;
Entry *Ax ;
Long p, d, j, i, k, n1cols, n1rows, row, col, pend, n2rows, n2cols = EMPTY,
nz2, kk, p2, col2, ynz, fill_reducing_ordering, m, n, xtype, worksize ;
cholmod_sparse *AT, *Y ;
// -------------------------------------------------------------------------
// get inputs
// -------------------------------------------------------------------------
xtype = spqr_type <Entry> ( ) ;
m = A->nrow ;
n = A->ncol ;
Ap = (Long *) A->p ;
Ai = (Long *) A->i ;
Ax = (Entry *) A->x ;
// set outputs to NULL in case of early return
*p_Q1fill = NULL ;
*p_R1p = NULL ;
*p_P1inv = NULL ;
*p_Y = NULL ;
*p_n1cols = EMPTY ;
*p_n1rows = EMPTY ;
// -------------------------------------------------------------------------
// allocate result Q1fill (Y, R1p, P1inv allocated later)
// -------------------------------------------------------------------------
Q1fill = (Long *) cholmod_l_malloc (n+bncols, sizeof (Long), cc) ;
// -------------------------------------------------------------------------
// allocate workspace
// -------------------------------------------------------------------------
fill_reducing_ordering = !
((ordering == SPQR_ORDERING_FIXED) ||
(ordering == SPQR_ORDERING_GIVEN) ||
(ordering == SPQR_ORDERING_NATURAL)) ;
worksize = ((fill_reducing_ordering) ? 3:2) * n ;
Work = (Long *) cholmod_l_malloc (worksize, sizeof (Long), cc) ;
Degree = Work ; // size n
Qrows = Work + n ; // size n
Winv = Qrows ; // Winv and Qrows not needed at the same time
W = Qrows + n ; // size n if fill-reducing ordering, else size 0
if (cc->status < CHOLMOD_OK)
{
// out of memory; free everything and return
cholmod_l_free (worksize, sizeof (Long), Work, cc) ;
cholmod_l_free (n+bncols, sizeof (Long), Q1fill, cc) ;
return (FALSE) ;
}
// -------------------------------------------------------------------------
// initialze queue with empty columns, and columns with just one entry
// -------------------------------------------------------------------------
n1cols = 0 ;
n1rows = 0 ;
for (j = 0 ; j < n ; j++)
{
p = Ap [j] ;
d = Ap [j+1] - p ;
if (d == 0)
{
// j is a dead column singleton
PR (("initial dead %ld\n", j)) ;
Q1fill [n1cols] = j ;
Qrows [n1cols] = EMPTY ;
n1cols++ ;
Degree [j] = EMPTY ;
}
else if (d == 1 && spqr_abs (Ax [p], cc) > tol)
{
// j is a column singleton, live or dead
PR (("initial live %ld %ld\n", j, Ai [p])) ;
Q1fill [n1cols] = j ;
Qrows [n1cols] = Ai [p] ; // this might be a duplicate
n1cols++ ;
Degree [j] = EMPTY ;
}
else
{
// j has degree > 1, it is not (yet) a singleton
Degree [j] = d ;
}
}
// Degree [j] = EMPTY if j is in the singleton queue, or the Degree [j] > 1
// is the degree of column j otherwise
// -------------------------------------------------------------------------
// create AT = spones (A')
// -------------------------------------------------------------------------
AT = cholmod_l_transpose (A, 0, cc) ; // [
if (cc->status < CHOLMOD_OK)
{
// out of memory; free everything and return
cholmod_l_free (worksize, sizeof (Long), Work, cc) ;
cholmod_l_free (n+bncols, sizeof (Long), Q1fill, cc) ;
return (FALSE) ;
}
ATp = (Long *) AT->p ;
ATj = (Long *) AT->i ;
// -------------------------------------------------------------------------
// remove column singletons via breadth-first-search
// -------------------------------------------------------------------------
for (k = 0 ; k < n1cols ; k++)
{
// ---------------------------------------------------------------------
// get a new singleton from the queue
// ---------------------------------------------------------------------
col = Q1fill [k] ;
row = Qrows [k] ;
PR (("\n---- singleton col %ld row %ld\n", col, row)) ;
ASSERT (Degree [col] == EMPTY) ;
if (row == EMPTY || ATp [row] < 0)
{
// -----------------------------------------------------------------
// col is a dead column singleton; remove duplicate row index
// -----------------------------------------------------------------
Qrows [k] = EMPTY ;
row = EMPTY ;
PR (("dead: %ld\n", col)) ;
}
else
{
// -----------------------------------------------------------------
// col is a live col singleton; remove its row from matrix
// -----------------------------------------------------------------
n1rows++ ;
p = ATp [row] ;
ATp [row] = FLIP (p) ; // flag the singleton row
pend = UNFLIP (ATp [row+1]) ;
PR (("live: %ld row %ld\n", col, row)) ;
for ( ; p < pend ; p++)
{
// look for new column singletons after row is removed
j = ATj [p] ;
d = Degree [j] ;
if (d == EMPTY)
{
// j is already in the singleton queue
continue ;
}
ASSERT (d >= 1) ;
ASSERT2 (spqrDebug_listcount (j, Q1fill, n1cols, 0) == 0) ;
d-- ;
Degree [j] = d ;
if (d == 0)
{
// a new dead col singleton
PR (("newly dead %ld\n", j)) ;
Q1fill [n1cols] = j ;
Qrows [n1cols] = EMPTY ;
n1cols++ ;
Degree [j] = EMPTY ;
}
else if (d == 1)
{
// a new live col singleton; find its single live row
for (p2 = Ap [j] ; p2 < Ap [j+1] ; p2++)
{
i = Ai [p2] ;
if (ATp [i] >= 0 && spqr_abs (Ax [p2], cc) > tol)
{
// i might appear in Qrows [k+1:n1cols-1]
PR (("newly live %ld\n", j)) ;
ASSERT2 (spqrDebug_listcount (i,Qrows,k+1,1) == 0) ;
Q1fill [n1cols] = j ;
Qrows [n1cols] = i ;
n1cols++ ;
Degree [j] = EMPTY ;
break ;
}
}
}
}
}
// Q1fill [0:k] and Qrows [0:k] have no duplicates
ASSERT2 (spqrDebug_listcount (col, Q1fill, n1cols, 0) == 1) ;
ASSERT2 (IMPLIES (row >= 0, spqrDebug_listcount
(row, Qrows, k+1, 1) == 1)) ;
}
// -------------------------------------------------------------------------
// Degree flags the column singletons, ATp flags their rows
// -------------------------------------------------------------------------
#ifndef NDEBUG
k = 0 ;
for (j = 0 ; j < n ; j++)
{
PR (("j %ld Degree[j] %ld\n", j, Degree [j])) ;
if (Degree [j] > 0) k++ ; // j is not a column singleton
}
PR (("k %ld n %ld n1cols %ld\n", k, n, n1cols)) ;
ASSERT (k == n - n1cols) ;
for (k = 0 ; k < n1cols ; k++)
{
col = Q1fill [k] ;
ASSERT (Degree [col] <= 0) ;
}
k = 0 ;
for (i = 0 ; i < m ; i++)
{
if (ATp [i] >= 0) k++ ; // i is not a row of a col singleton
}
ASSERT (k == m - n1rows) ;
for (k = 0 ; k < n1cols ; k++)
{
row = Qrows [k] ;
ASSERT (IMPLIES (row != EMPTY, ATp [row] < 0)) ;
}
#endif
// -------------------------------------------------------------------------
// find the row ordering
// -------------------------------------------------------------------------
if (n1cols == 0)
{
// ---------------------------------------------------------------------
// no singletons in the matrix; no R1 matrix, no P1inv permutation
// ---------------------------------------------------------------------
ASSERT (n1rows == 0) ;
R1p = NULL ;
P1inv = NULL ;
}
else
{
// ---------------------------------------------------------------------
// construct the row singleton permutation
// ---------------------------------------------------------------------
// allocate result arrays R1p and P1inv
R1p = (Long *) cholmod_l_malloc (n1rows+1, sizeof (Long), cc) ;
P1inv = (Long *) cholmod_l_malloc (m, sizeof (Long), cc) ;
if (cc->status < CHOLMOD_OK)
{
// out of memory; free everything and return
cholmod_l_free_sparse (&AT, cc) ;
cholmod_l_free (worksize, sizeof (Long), Work, cc) ;
cholmod_l_free (n+bncols, sizeof (Long), Q1fill, cc) ;
cholmod_l_free (n1rows+1, sizeof (Long), R1p, cc) ;
cholmod_l_free (m, sizeof (Long), P1inv, cc) ;
return (FALSE) ;
}
#ifndef NDEBUG
for (i = 0 ; i < m ; i++) P1inv [i] = EMPTY ;
#endif
kk = 0 ;
for (k = 0 ; k < n1cols ; k++)
{
i = Qrows [k] ;
PR (("singleton col %ld row %ld\n", Q1fill [k], i)) ;
if (i != EMPTY)
{
// row i is the kk-th singleton row
ASSERT (ATp [i] < 0) ;
ASSERT (P1inv [i] == EMPTY) ;
P1inv [i] = kk ;
// also find # of entries in row kk of R1
R1p [kk] = UNFLIP (ATp [i+1]) - UNFLIP (ATp [i]) ;
kk++ ;
}
}
ASSERT (kk == n1rows) ;
for (i = 0 ; i < m ; i++)
{
if (ATp [i] >= 0)
{
// row i is not a singleton row
ASSERT (P1inv [i] == EMPTY) ;
P1inv [i] = kk ;
kk++ ;
}
}
ASSERT (kk == m) ;
}
// Qrows is no longer needed.
// -------------------------------------------------------------------------
// complete the column ordering
// -------------------------------------------------------------------------
if (!fill_reducing_ordering)
{
// ---------------------------------------------------------------------
// natural ordering
// ---------------------------------------------------------------------
if (n1cols == 0)
{
// no singletons, so natural ordering is 0:n-1 for now
for (k = 0 ; k < n ; k++)
{
Q1fill [k] = k ;
}
}
else
{
// singleton columns appear first, then non column singletons
k = n1cols ;
for (j = 0 ; j < n ; j++)
{
if (Degree [j] > 0)
{
// column j is not a column singleton
Q1fill [k++] = j ;
}
}
ASSERT (k == n) ;
}
}
else
{
// ---------------------------------------------------------------------
// fill-reducing ordering of pruned submatrix
// ---------------------------------------------------------------------
if (n1cols == 0)
{
// -----------------------------------------------------------------
// no singletons found; do fill-reducing on entire matrix
// -----------------------------------------------------------------
n2cols = n ;
n2rows = m ;
}
else
{
// -----------------------------------------------------------------
// create the pruned matrix for fill-reducing by removing singletons
// -----------------------------------------------------------------
// find the mapping of original columns to pruned columns
n2cols = 0 ;
for (j = 0 ; j < n ; j++)
{
if (Degree [j] > 0)
{
// column j is not a column singleton
W [j] = n2cols++ ;
PR (("W [%ld] = %ld\n", j, W [j])) ;
}
else
{
// column j is a column singleton
W [j] = EMPTY ;
PR (("W [%ld] = %ld (j is col singleton)\n", j, W [j])) ;
}
}
ASSERT (n2cols == n - n1cols) ;
// W is now a mapping of the original columns to the columns in the
// pruned matrix. W [col] == EMPTY if col is a column singleton.
// Otherwise col2 = W [j] is a column of the pruned matrix.
// -----------------------------------------------------------------
// delete row and column singletons from A'
// -----------------------------------------------------------------
// compact A' by removing row and column singletons
nz2 = 0 ;
n2rows = 0 ;
for (i = 0 ; i < m ; i++)
{
p = ATp [i] ;
if (p >= 0)
{
// row i is not a row of a column singleton
ATp [n2rows++] = nz2 ;
pend = UNFLIP (ATp [i+1]) ;
for (p = ATp [i] ; p < pend ; p++)
{
j = ATj [p] ;
ASSERT (W [j] >= 0 && W [j] < n-n1cols) ;
ATj [nz2++] = W [j] ;
}
}
}
ATp [n2rows] = nz2 ;
ASSERT (n2rows == m - n1rows) ;
}
// ---------------------------------------------------------------------
// fill-reducing ordering of the transpose of the pruned A' matrix
// ---------------------------------------------------------------------
PR (("n1cols %ld n1rows %ld n2cols %ld n2rows %ld\n",
n1cols, n1rows, n2cols, n2rows)) ;
ASSERT ((Long) AT->nrow == n) ;
ASSERT ((Long) AT->ncol == m) ;
AT->nrow = n2cols ;
AT->ncol = n2rows ;
// save the current CHOLMOD settings
Long save [6] ;
save [0] = cc->supernodal ;
save [1] = cc->nmethods ;
save [2] = cc->postorder ;
save [3] = cc->method [0].ordering ;
save [4] = cc->method [1].ordering ;
save [5] = cc->method [2].ordering ;
// follow the ordering with a postordering of the column etree
cc->postorder = TRUE ;
// 8:best: best of COLAMD(A), AMD(A'A), and METIS (if available)
if (ordering == SPQR_ORDERING_BEST)
{
ordering = SPQR_ORDERING_CHOLMOD ;
cc->nmethods = 2 ;
cc->method [0].ordering = CHOLMOD_COLAMD ;
cc->method [1].ordering = CHOLMOD_AMD ;
#ifndef NPARTITION
cc->nmethods = 3 ;
cc->method [2].ordering = CHOLMOD_METIS ;
#endif
}
// 9:bestamd: best of COLAMD(A) and AMD(A'A)
if (ordering == SPQR_ORDERING_BESTAMD)
{
// if METIS is not installed, this option is the same as 8:best
ordering = SPQR_ORDERING_CHOLMOD ;
cc->nmethods = 2 ;
cc->method [0].ordering = CHOLMOD_COLAMD ;
cc->method [1].ordering = CHOLMOD_AMD ;
}
#ifdef NPARTITION
if (ordering == SPQR_ORDERING_METIS)
{
// METIS not installed; use default ordering
ordering = SPQR_ORDERING_DEFAULT ;
}
#endif
if (ordering == SPQR_ORDERING_DEFAULT)
{
// Version 1.2.0: just use COLAMD
ordering = SPQR_ORDERING_COLAMD ;
#if 0
// Version 1.1.2 and earlier:
if (n2rows <= 2*n2cols)
{
// just use COLAMD; do not try AMD or METIS
ordering = SPQR_ORDERING_COLAMD ;
}
else
{
#ifndef NPARTITION
// use CHOLMOD's default ordering: try AMD and then METIS
// if AMD gives high fill-in, and take the best ordering found
ordering = SPQR_ORDERING_CHOLMOD ;
cc->nmethods = 0 ;
#else
// METIS is not installed, so just use AMD
ordering = SPQR_ORDERING_AMD ;
#endif
}
#endif
}
if (ordering == SPQR_ORDERING_AMD)
{
// use CHOLMOD's interface to AMD to order A'*A
cholmod_l_amd (AT, NULL, 0, (Long *) (Q1fill + n1cols), cc) ;
}
#ifndef NPARTITION
else if (ordering == SPQR_ORDERING_METIS)
{
// use CHOLMOD's interface to METIS to order A'*A (if installed)
cholmod_l_metis (AT, NULL, 0, TRUE,
(Long *) (Q1fill + n1cols), cc) ;
}
#endif
else if (ordering == SPQR_ORDERING_CHOLMOD)
{
// use CHOLMOD's internal ordering (defined by cc) to order AT
PR (("Using CHOLMOD, nmethods %d\n", cc->nmethods)) ;
cc->supernodal = CHOLMOD_SIMPLICIAL ;
cc->postorder = TRUE ;
cholmod_factor *Sc ;
Sc = cholmod_l_analyze_p2 (FALSE, AT, NULL, NULL, 0, cc) ;
if (Sc != NULL)
{
// copy perm from Sc->Perm [0:n2cols-1] to Q1fill (n1cols:n)
Long *Sc_perm = (Long *) Sc->Perm ;
for (k = 0 ; k < n2cols ; k++)
{
Q1fill [k + n1cols] = Sc_perm [k] ;
}
// CHOLMOD selected an ordering; determine the ordering used
switch (Sc->ordering)
{
case CHOLMOD_AMD: ordering = SPQR_ORDERING_AMD ;break;
case CHOLMOD_COLAMD: ordering = SPQR_ORDERING_COLAMD ;break;
case CHOLMOD_METIS: ordering = SPQR_ORDERING_METIS ;break;
}
}
cholmod_l_free_factor (&Sc, cc) ;
PR (("CHOLMOD used method %d : ordering: %d\n", cc->selected,
cc->method [cc->selected].ordering)) ;
}
else // SPQR_ORDERING_DEFAULT or SPQR_ORDERING_COLAMD
{
// use CHOLMOD's interface to COLAMD to order AT
ordering = SPQR_ORDERING_COLAMD ;
cholmod_l_colamd (AT, NULL, 0, TRUE,
(Long *) (Q1fill + n1cols), cc) ;
}
cc->SPQR_istat [7] = ordering ;
// restore the CHOLMOD settings
cc->supernodal = save [0] ;
cc->nmethods = save [1] ;
cc->postorder = save [2] ;
cc->method [0].ordering = save [3] ;
cc->method [1].ordering = save [4] ;
cc->method [2].ordering = save [5] ;
AT->nrow = n ;
AT->ncol = m ;
}
// -------------------------------------------------------------------------
// free AT
// -------------------------------------------------------------------------
cholmod_l_free_sparse (&AT, cc) ; // ]
// -------------------------------------------------------------------------
// check if the method succeeded
// -------------------------------------------------------------------------
if (cc->status < CHOLMOD_OK)
{
// out of memory; free everything and return
cholmod_l_free (worksize, sizeof (Long), Work, cc) ;
cholmod_l_free (n+bncols, sizeof (Long), Q1fill, cc) ;
cholmod_l_free (n1rows+1, sizeof (Long), R1p, cc) ;
cholmod_l_free (m, sizeof (Long), P1inv, cc) ;
return (FALSE) ;
}
// -------------------------------------------------------------------------
// map the fill-reducing ordering ordering back to A
// -------------------------------------------------------------------------
if (n1cols > 0 && fill_reducing_ordering)
{
// Winv is workspace of size n2cols <= n
#ifndef NDEBUG
for (j = 0 ; j < n2cols ; j++) Winv [j] = EMPTY ;
#endif
for (j = 0 ; j < n ; j++)
{
// j is a column of A. col2 = W [j] is either EMPTY, or it is
// the corresponding column of the pruned matrix
col2 = W [j] ;
if (col2 != EMPTY)
{
ASSERT (col2 >= 0 && col2 < n2cols) ;
Winv [col2] = j ;
}
}
for (k = n1cols ; k < n ; k++)
{
// col2 is a column of the pruned matrix
col2 = Q1fill [k] ;
// j is the corresonding column of the A matrix
j = Winv [col2] ;
ASSERT (j >= 0 && j < n) ;
Q1fill [k] = j ;
}
}
// -------------------------------------------------------------------------
// identity permutation of the columns of B
// -------------------------------------------------------------------------
for (k = n ; k < n+bncols ; k++)
{
// tack on the identity permutation for columns of B
Q1fill [k] = k ;
}
// -------------------------------------------------------------------------
// find column pointers for Y = [A2 B2]; columns of A2
// -------------------------------------------------------------------------
if (n1cols == 0 && bncols == 0)
{
// A will be factorized instead of Y
Y = NULL ;
}
else
{
// Y has no entries yet; nnz(Y) will be determined later
Y = cholmod_l_allocate_sparse (m-n1rows, n-n1cols+bncols, 0,
FALSE, TRUE, 0, xtype, cc) ;
if (cc->status < CHOLMOD_OK)
{
// out of memory; free everything and return
cholmod_l_free (worksize, sizeof (Long), Work, cc) ;
cholmod_l_free (n+bncols, sizeof (Long), Q1fill, cc) ;
cholmod_l_free (n1rows+1, sizeof (Long), R1p, cc) ;
cholmod_l_free (m, sizeof (Long), P1inv, cc) ;
return (FALSE) ;
}
Yp = (Long *) Y->p ;
ynz = 0 ;
PR (("1c wrapup: n1cols %ld n %ld\n", n1cols, n)) ;
for (k = n1cols ; k < n ; k++)
{
j = Q1fill [k] ;
d = Degree [j] ;
ASSERT (d >= 1 && d <= m) ;
Yp [k-n1cols] = ynz ;
ynz += d ;
}
Yp [n-n1cols] = ynz ;
}
// -------------------------------------------------------------------------
// free workspace and return results
// -------------------------------------------------------------------------
cholmod_l_free (worksize, sizeof (Long), Work, cc) ;
*p_Q1fill = Q1fill ;
*p_R1p = R1p ;
*p_P1inv = P1inv ;
*p_Y = Y ;
*p_n1cols = n1cols ;
*p_n1rows = n1rows ;
return (TRUE) ;
}
void mexFunction
(
int nargout,
mxArray *pargout [ ],
int nargin,
const mxArray *pargin [ ]
)
{
#ifndef NPARTITION
double dummy = 0 ;
Long *Perm ;
cholmod_sparse *A, Amatrix, *C, *S ;
cholmod_common Common, *cm ;
Long n, transpose, c, postorder ;
char buf [LEN] ;
/* ---------------------------------------------------------------------- */
/* start CHOLMOD and set defaults */
/* ---------------------------------------------------------------------- */
cm = &Common ;
cholmod_l_start (cm) ;
sputil_config (SPUMONI, cm) ;
/* ---------------------------------------------------------------------- */
/* get inputs */
/* ---------------------------------------------------------------------- */
if (nargout > 1 || nargin < 1 || nargin > 3)
{
mexErrMsgTxt ("Usage: p = metis (A, mode)") ;
}
/* ---------------------------------------------------------------------- */
/* get input matrix A */
/* ---------------------------------------------------------------------- */
A = sputil_get_sparse_pattern (pargin [0], &Amatrix, &dummy, cm) ;
S = (A == &Amatrix) ? NULL : A ;
/* ---------------------------------------------------------------------- */
/* get A->stype, default is to use tril(A) */
/* ---------------------------------------------------------------------- */
A->stype = -1 ;
transpose = FALSE ;
if (nargin > 1)
{
buf [0] = '\0' ;
if (mxIsChar (pargin [1]))
{
mxGetString (pargin [1], buf, LEN) ;
}
c = buf [0] ;
if (tolower (c) == 'r')
{
/* unsymmetric case (A*A') if string starts with 'r' */
transpose = FALSE ;
A->stype = 0 ;
}
else if (tolower (c) == 'c')
{
/* unsymmetric case (A'*A) if string starts with 'c' */
transpose = TRUE ;
A->stype = 0 ;
}
else if (tolower (c) == 's')
{
/* symmetric case (A) if string starts with 's' */
transpose = FALSE ;
A->stype = -1 ;
}
else
{
mexErrMsgTxt ("metis: p=metis(A,mode) ; unrecognized mode") ;
}
}
if (A->stype && A->nrow != A->ncol)
{
mexErrMsgTxt ("metis: A must be square") ;
}
C = NULL ;
if (transpose)
{
/* C = A', and then order C*C' with METIS */
C = cholmod_l_transpose (A, 0, cm) ;
if (C == NULL)
{
mexErrMsgTxt ("metis failed") ;
}
A = C ;
}
n = A->nrow ;
/* ---------------------------------------------------------------------- */
/* get workspace */
/* ---------------------------------------------------------------------- */
Perm = cholmod_l_malloc (n, sizeof (Long), cm) ;
/* ---------------------------------------------------------------------- */
/* order the matrix with CHOLMOD's interface to METIS_NodeND */
/* ---------------------------------------------------------------------- */
postorder = (nargin < 3) ;
if (!cholmod_l_metis (A, NULL, 0, postorder, Perm, cm))
{
mexErrMsgTxt ("metis failed") ;
return ;
}
/* ---------------------------------------------------------------------- */
/* return Perm */
/* ---------------------------------------------------------------------- */
pargout [0] = sputil_put_int (Perm, n, 1) ;
/* ---------------------------------------------------------------------- */
/* free workspace */
/* ---------------------------------------------------------------------- */
cholmod_l_free (n, sizeof (Long), Perm, cm) ;
cholmod_l_free_sparse (&C, cm) ;
cholmod_l_free_sparse (&S, cm) ;
cholmod_l_finish (cm) ;
cholmod_l_print_common (" ", cm) ;
/*
if (cm->malloc_count != 0) mexErrMsgTxt ("!") ;
*/
#else
mexErrMsgTxt ("METIS and the CHOLMOD Partition Module not installed\n") ;
#endif
}
