[cig-commits] r14875 - short/3D/PyLith/trunk/doc/developer

[brad at geodynamics.org]

Author: brad
Date: 2009-05-05 13:32:30 -0700 (Tue, 05 May 2009)
New Revision: 14875

Added:
   short/3D/PyLith/trunk/doc/developer/Sieve
Log:
Added some general developer notes.

Added: short/3D/PyLith/trunk/doc/developer/Sieve
===================================================================
--- short/3D/PyLith/trunk/doc/developer/Sieve	                        (rev 0)
+++ short/3D/PyLith/trunk/doc/developer/Sieve	2009-05-05 20:32:30 UTC (rev 14875)
@@ -0,0 +1,36 @@
+Notes on Sieve
+
+* Depth/height
+
+  In general, vertices are at a depth of 0 and cells are at the
+  maximum depth. Similarly, cells are at a height of 0 and vertices
+  are at the maximum depth.
+
+  For a 3-D mesh with vertices, edges, faces, and cells:
+
+               Depth  Height
+    vertices   0      3
+    edges      1      2
+    faces      2      1
+    cells      3      0
+
+  For a boundary mesh, we currently store the full set (vertices,
+  edges, faces, and cells). Obviously for 2-D meshes, the boundary
+  mesh doesn't contain "volume" cells, but just vertices, edges, and
+  faces. This means the "boundary" cells are at a height of 1 and
+  maximum depth - 1 .
+
+  The fault mesh is generated with its own numbering, so it is
+  different and it only contains vertices and "faces" where "faces"
+  means faces for a 3-D mesh and edges for a 2-D mesh.
+
+
+* Fiber dimension
+
+  Fiber dimension refers to the number of values at a point.
+
+* Section/Field
+
+  Sections generally refer to the Sieve data structure, whereas Fields
+  refer to a vector field. The PyLith Field class stores a vector
+  field over vertices or cells.