# DMSTAG#

"stag" - A DM object representing a “staggered grid” or a structured cell complex. See the manual chapter on DMStag.

This implementation parallels the DMDA implementation in many ways, but allows degrees of freedom to be associated with all “strata” in a logically-rectangular grid.

Each stratum can be characterized by the dimension of the entities (“points”, to borrow the DMPLEX terminology), from 0- to 3-dimensional.

In some cases this numbering is used directly, for example with DMStagGetDOF(). To allow easier reading and to some extent more similar code between different-dimensional implementations of the same problem, we associate canonical names for each type of point, for each dimension of DMStag.

• 1-dimensional DMStag objects have vertices (0D) and elements (1D).

• 2-dimensional DMStag objects have vertices (0D), faces (1D), and elements (2D).

• 3-dimensional DMStag objects have vertices (0D), edges (1D), faces (2D), and elements (3D).

This naming is reflected when viewing a DMStag object with DMView(), and in forming convenient options prefixes when creating a decomposition with DMCreateFieldDecomposition().

DM, DMPRODUCT, DMDA, DMPLEX, DMStagCreate1d(), DMStagCreate2d(), DMStagCreate3d(), DMType, DMCreate(), DMSetType()