1# Example macro triangulation for a mesh with periodic boundaries: a 2# topological torus. 3 4DIM: 2 5DIM_OF_WORLD: 2 6 7number of elements: 8 8number of vertices: 9 9 10element vertices: 11 4 0 1 12 2 4 1 13 4 2 5 14 8 4 5 15 4 8 7 16 6 4 7 17 4 6 3 18 0 4 3 19 20vertex coordinates: 21 -1.0 -1.0 22 0.0 -1.0 23 1.0 -1.0 24 -1.0 0.0 25 0.0 0.0 26 1.0 0.0 27 -1.0 1.0 28 0.0 1.0 29 1.0 1.0 30 31# Neighbours need not be specified, but if so, then the neighbourhood 32# information should treat periodic faces as interior faces. We leave 33# the neighbourhood information commented out such that it can be 34# determined by the geometric face transformations. 35 36# example for a torus: 37# element neighbours: 38# 5 1 7 39# 0 4 2 40# 7 3 1 41# 2 6 4 42# 1 5 3 43# 4 0 6 44# 3 7 5 45# 6 2 0 46 47# In principle it is possible to specify boundary types for periodic 48# faces; those are ignored during "normal" operation, but can be 49# accessed by using the special fill-flag FILL_NON_PERIODIC during 50# mesh-traversal. This is primarily meant for defining parametric 51# periodic meshes: the finite element function defining the mesh 52# geometry is -- of course -- not periodic. 53 54element boundaries: 55 2 0 0 56 0 2 0 57 1 0 0 58 0 1 0 59 2 0 0 60 0 2 0 61 1 0 0 62 0 1 0 63 64# Geometric face transformations. It is also possible to specify those 65# in the application program. 66# 67number of wall transformations: 2 68 69wall transformations: 70# generator #1 71 1 0 2 72 0 1 0 73 0 0 1 74# generator #2 75 1 0 0 76 0 1 2 77 0 0 1 78 79# For each face of each element of the triangulation the number of the 80# face transformation attached to it. Counting starts at 1, negative 81# numbers mean the inverse. Expected is the face transformation which 82# maps the macro triangulation to its neighbour across the respective 83# face. It is possible to omit this section in which case the 84# per-element face transformations are computed. 85# 86#element wall transformations: 87# -2 0 0 88# 0 -2 0 89# 1 0 0 90# 0 1 0 91# 2 0 0 92# 0 2 0 93# -1 0 0 94# 0 -1 0 95 96# Combinatorical face transformations. These, too, can be omitted. 97# 98# You will observe that there are "duplicate lines" below. Indeed, but 99# this does not matter: you really have to group the vertex-mappings 100# in pairs, the first two lines mean: 101# 102# "map the face defined by vertex 0 and 1 to the face defined by 103# vertex 6 and 7, in that orientation". 104# 105#number of wall vertex transformations: 4 106 107#wall vertex transformations: 108# 0 6 109# 1 7 110 111# 1 7 112# 2 8 113 114# 0 2 115# 3 5 116 117# 3 5 118# 6 8 119 120# (X)Emacs stuff (for editing purposes) 121# Local Variables: *** 122# comment-start: "# " *** 123# End: *** 124