Scotch Brand 5.1.10 - Manual (Page 101)

the reference to the adjacency end index array, and is equal to verttab + 1
if the adjacency array is compact. velotab and vnlotab are pointers to
locations that will hold the reference to the element and node vertex load
arrays, of sizes *velmptr and *vnodptr, respectively. vlbltab is the pointer
to a location that will hold the reference to the vertex label array, of size
(*velmptr + *vnodptr). edgeptr is the pointer to a location that will hold
the number of arcs (that is, twice the number of edges). edgetab is the pointer
to a location that will hold the reference to the adjacency array, of size at least
edgenbr
. degrptr is the pointer to a location that will hold the maximum
vertex degree computed across all element and node vertices.
Any of these pointers can be set to NULL on input if the corresponding infor-
mation is not needed. Else, the reference to a dummy area can be provided,
where all unwanted data will be written.
Since there are no pointers in Fortran, a specific mechanism is used to allow
users to access mesh arrays. The scotchfmeshdata routine is passed an inte-
ger array, the first element of which is used as a base address from which all
other array indices are computed. Therefore, instead of returning references,
the routine returns integers, which represent the starting index of each of the
relevant arrays with respect to the base input array, or vertidx, the index
of verttab, if they do not exist. For instance, if some base array myarray
(1)
is passed as parameter indxtab, then the first cell of array verttab will
be accessible as myarray(vertidx). In order for this feature to behave prop-
erly, the indxtab array must be word-aligned with the mesh arrays. This is
automatically enforced on most systems, but some care should be taken on
systems that allow one to access data that is not word-aligned. On such sys-
tems, declaring the array after a dummy doubleprecision array can coerce
the compiler into enforcing the proper alignment. Also, on 32 64 architec-
tures, such indices can be larger than the size of a regular INTEGER. This is
why the indices to be returned are defined by means of a specific integer type.
See Section 7.1.4 for more information on this issue.
7.8.9 SCOTCH meshStat
Synopsis
void SCOTCH meshStat (const SCOTCH Mesh * meshptr,
SCOTCH Num * vnlominptr,
SCOTCH Num * vnlomaxptr,
SCOTCH Num * vnlosumptr,
double * vnloavgptr,
double * vnlodltptr,
SCOTCH Num * edegminptr,
SCOTCH Num * edegmaxptr,
double * edegavgptr,
double * edegdltptr,
SCOTCH Num * ndegminptr,
SCOTCH Num * ndegmaxptr,
double * ndegavgptr,
double * ndegdltptr)
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