7. Subsetting

Meshes are frequently composed of a variety of subsets that represent different portions of the mesh. Common examples are domains, groups (of domains), AMR patches and levels, part assemblies, boundary conditions, node sets and zone sets, materials and even material species.

Users often find it useful to restrict which subsets are used in any given operation to focus their analyses on only certain regions of interest. This is handled through VisIt’s Subset Window. Here, we describe VisIt’s subsetting functionality and Subset Window in detail.

What is described here is primarily about pre-defined, first-class, named subsets as created by the data producer and supported within VisIt. Nonetheless, It is important to keep in mind that there are other ways that the data producer can organize data within VisIt’s GUI or that users can employ VisIt’s Expressions and Operators to create and manage subsets. However, using these other approaches for the sole purpose of subsetting is often cumbersome through VisIt’s GUI. To understand why as well as read about other issues related to subsetting, please see these developer notes.