/usr/share/dune-grid/grids/amc/periodic-torus.amc is in libdune-grid-dev 2.5.1-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | # Example macro triangulation for a mesh with periodic boundaries: a
# topological torus.
DIM: 2
DIM_OF_WORLD: 2
number of elements: 8
number of vertices: 9
element vertices:
4 0 1
2 4 1
4 2 5
8 4 5
4 8 7
6 4 7
4 6 3
0 4 3
vertex coordinates:
-1.0 -1.0
0.0 -1.0
1.0 -1.0
-1.0 0.0
0.0 0.0
1.0 0.0
-1.0 1.0
0.0 1.0
1.0 1.0
# Neighbours need not be specified, but if so, then the neighbourhood
# information should treat periodic faces as interior faces. We leave
# the neighbourhood information commented out such that it can be
# determined by the geometric face transformations.
# example for a torus:
# element neighbours:
# 5 1 7
# 0 4 2
# 7 3 1
# 2 6 4
# 1 5 3
# 4 0 6
# 3 7 5
# 6 2 0
# In principle it is possible to specify boundary types for periodic
# faces; those are ignored during "normal" operation, but can be
# accessed by using the special fill-flag FILL_NON_PERIODIC during
# mesh-traversal. This is primarily meant for defining parametric
# periodic meshes: the finite element function defining the mesh
# geometry is -- of course -- not periodic.
element boundaries:
2 0 0
0 2 0
1 0 0
0 1 0
2 0 0
0 2 0
1 0 0
0 1 0
# Geometric face transformations. It is also possible to specify those
# in the application program.
#
number of wall transformations: 2
wall transformations:
# generator #1
1 0 2
0 1 0
0 0 1
# generator #2
1 0 0
0 1 2
0 0 1
# For each face of the triangulation the number of the face
# transformation attached to it. Counting starts at 1, negative
# numbers mean the inverse. Expected is the face transformation which
# maps the macro triangulation to its neighbour across the respective
# face. It is possible to omit this section in which case the
# per-element face transformations are computed.
#
#element wall transformations:
# -2 0 0
# 0 -2 0
# 1 0 0
# 0 1 0
# 2 0 0
# 0 2 0
# -1 0 0
# 0 -1 0
# Combinatorical face transformations. These, too, can be omitted.
#
# You will observe that there are "duplicate lines" below. Indeed, but
# this does not matter: you really have to group the vertex-mappings
# in pairs, the first two lines mean:
#
# "map the face defined by vertex 0 and 1 to the face defined by
# vertex 6 and 7, in that orientation".
#
#number of wall vertex transformations: 4
#wall vertex transformations:
# 0 6
# 1 7
# 1 7
# 2 8
# 0 2
# 3 5
# 3 5
# 6 8
# (X)Emacs stuff (for editing purposes)
# Local Variables: ***
# comment-start: "# " ***
# End: ***
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