Scotch Brand 5.1.10 User Manual
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edgenbr
vlbltab
velotab
vnodnbr
velmbas
vnodbas
velmnbr
verttab
edgetab
vendtab
24
11
12
13 16 19
12 13
16 19 22 25
22
11 11 12 13 11 12 14 13 13 14 12 14
1 2 5 8 9
2 5 8 9
1 2 3 5 2 3 4 5 2 3 6 5
1
2
3
4
5
6
0 0 0 0
0 0 0 0
1
6
4
12
11
13
14
Figure 19: Sample mesh and its description by libScotch arrays, with nodes
numbered first and elements numbered last. In order to allow for dynamic re-
meshing, empty elements (in grey) have been inserted between existing node and
element vertices.
a mesh that has already been declared using the SCOTCH meshBuild routine must
call SCOTCH meshExit prior to updating the mesh arrays, and then call SCOTCH
meshBuild
again after the arrays have been updated, so that the SCOTCH Mesh
structure remains consistent with the new mesh data.
7.2.4
Geometry format
Geometry data is always associated with a graph or a mesh. It is simply made
of a single array of double-precision values which represent the coordinates of the
vertices of a graph, or of the node vertices of a mesh, in vertex order. The fields of
a geometry structure are the following:
dimnnbr
Number of dimensions of the graph or of the mesh, which can be 1, 2, or 3.
geomtab
Array of coordinates. This is an array of double precision values organized
as an array of (x), or (x,y), or (x,y,z) tuples, according to dimnnbr. Co-
ordinates that are not used (e.g. the “z” coordinates for a 2-dimentional
object) are not allocated.
Therefore, the “x” coordinate of some graph
vertex i is located at geomtab[(i - baseval) * dimnnbr + baseval], its
“y” coordinate is located at geomtab[(i - baseval) * dimnnbr + baseval
+ 1]
if dimnnbr ≤ 2, and its “z” coordinate is located at geomtab[(i -
baseval) * dimnnbr + baseval + 2]
if dimnnbr = 3. Whenever the ge-
ometry is associated with a mesh, only node vertices are considered, so
the “x” coordinate of some mesh node vertex i, with vnodbas ≤ i, is lo-
cated at geomtab[(i - vnodbas) * dimnnbr + baseval], its “y” coordi-
nate is located at geomtab[(i - vnodbas) * dimnnbr + baseval + 1] if
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