(3M) Calculator User Manual

vertnbr − 1 if the graph base is 0, and from 1 to vertnbr if the graph base
is 1.
The three other result fields, *cblkptr, rangtab and treetab, contain data
related to the block structure. *cblkptr holds the number of column blocks
of the produced o rdering, and rangtab holds the starting indices of each of the
permuted column blocks, in increasing order, so that column block i starts at
index rangtab[i] and ends at index (rangtab[i+1]−1), inclusive, in the new
ordering. treetab holds the se parators tree structure, that is, treetab[i] is
the index of the father of co lumn block i in the sepa rators tree, or −1 if column
block i is the root of the separators tree. Please refer to Section 7.2.5 for more
information.
Return val ues
SCOTCH
graphOrder returns 0 if the ordering of the graph has been successfully
computed, a nd 1 els e. In this last case, the rangtab, permtab, and peritab
arrays may however have been partially or completely filled, but their contents
are not significant.
7.7.2 SCOTCH graphOrderInit
Synopsis
int SCOTCH graphOrderInit (const SCOTCH Graph * grafptr,
SCOTCH
Ordering * ordeptr,
SCOTCH Num * permtab,
SCOTCH
Num * peritab,
SCOTCH Num * cblkptr,
SCOTCH Num * rangtab,
SCOTCH
Num * treetab)
scotchfgraphorderinit (doubleprecision (*) grafdat,
doubleprecision (*) ordedat,
integer*num (*) permtab,
integer*num (*) peritab,
integer*num cblknbr,
integer*num (*) rangtab,
integer*num (*) treetab,
integer ierr)
Description
The SCOTCH
graphOrderInit routine fills the ordering structure pointed to by
ordeptr with all of the data that are passed to it. Thus, all subsequent calls
to ordering routines such as SCOTCH
graphOrderCompute, using this ordering
structure as parameter, will place ordering results in fields permtab, peritab,
*cblkptr, rangtab or treetab, if they are not set to NULL.
permtab is the o rdering permutation array, of size vertnbr, peritab is the
inverse ordering pe rmutation array, of size vertnbr, cblkptr is the pointer
to a SCOTCH
Num that will receive the number of produced column blocks,
rangtab is the array that holds the column block span information, of size
90