(3M) Calculator User Manual

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 des cription by libScotch arrays, with nodes
numbered firs t and elements numbere d last. In order to allow for dynamic re-
meshing, e mpty elements (in gr e y) 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 tha t 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 ve rtex 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 org anized
as an array of (x), or (x,y), or (x,y,z) tuples, according to dimnnbr. Co-
ordinates that are no t 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” coo rdinate 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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