NAME

     ijktable - format of an isosurface table file

DESCRIPTION

     An isosurface table  file  defines  a  table  of  isosurface
     patches  of  an  arbitrary polyhedron in an arbitrary dimen-
     sion.  The file consists of the dimension  followed  by  the
     description  of the polyhedron followed by the table of iso-
     surface patches.

     The polyhedron is described by a list of vertex  coordinates
     followed  by  a  list of edges followed by a list of facets.
     Other polyhedron faces are not recorded.

     The isosurface table is a list of table entries.  Each  iso-
     surface  table  entry  contains  a list of polyhedron edges.
     The i'th vertex of the j'th  simplex  is  contained  in  the
     i+j*d'th  edge in this list where d is the polyhedron dimen-
     sion.

GRAMMAR

     <isosurface table>:
          <file header>
          <dimension>
          <vertex header>
          <number of vertices>
          <vertex coordinate list>
          <edge header>
          <number of edges>
          <edge list>
          <facet header>
          <number of facets>
          <facet list>
          <table header>
          <isosurface patch list>

     <file header>:
          <ISOTABLE2>

     <dimension>:
          2 | 3 | 4

     <vertex header>:
          <VERTICES>

     <number of vertices>:
          integer

     <vertex coordinate list>:
          <vertex coordinate> <vertex coordinate list> |
          <vertex coordinate>

     <vertex coordinate>:
          integer

     <edge header>:
          <EDGES>

     <number of edges>:
          integer

     <edge list>:
          <vertex> <vertex> <edge list> |
          <vertex> <vertex>

     <vertex>:
          integer

     <facet header>:
          <FACETS>

     <number of facets>:
          integer

     <facet list>:
          <facet> <facet list> |
          <facet> |
          <>

     <facet>:
          <number of facet vertices> <facet vertex list>

     <number of facet vertices>:
          integer

     <facet vertex list>:
          <vertex> <facet vertex list> |
          <vertex> |
          <>

     <table header>:
          <TABLE>

     <isosurface patch list>:
          <isosurface patch> <isosurface patch list> |
          <isosurface patch>

     <isosurface patch>:
          <number of simplices> <simplex list> |
          0

     <simplex list>:
          <simplex> <simplex list> |
          <simplex>

     <simplex>:
          <edge> <simplex> |
          <edge>

     <edge>:
          integer

NOTES

     -- Number of vertex coordinates in <vertex coordinate  list>
     is   <dimension>   *   <number   of   vertices>.    The  (k-
     1)*<dimension> + 1 through k*<dimension> coordinates in  the
     list are coordinates of the k'th vertex.

     -- Number of vertices in  <edge  coordinate  list>  is  2  *
     <number  of  edges>.   The  2*k-1 and 2*k'th vertices in the
     list are endpoints of the k'th edge.

     -- Each <vertex> is an integer  between  0  and  <number  of
     vertices>-1.

     -- Number of surface patches in <isosurface patch  list>  is
     2^<number of vertices>.

     -- The number of simplices in the <simplex list> is  <number
     of simplices>.

     -- The number of edges in each <simplex> is <dimension>.

     -- Each <edge> is  an  integer  between  0  and  <number  of
     edges>-1.

     -- Number of facets in <facet list> is <number of facets>.

     -- Number of vertices in <facet vertex list> is  <number  of
     facet vertices>.

     This format replaces an older version which did not  contain
     facet information and did not contain vertex, edge, facet or
     table headers.

AUTHOR

     Rephael Wenger