Selecting this item brings up a window which allows you to create your own variables for MeshTV to plot.
The Expression window should look like Expression window , if you have never saved your own expressions via the Save settings menu item.
The Expression window allows you to create your own variables from existing variables via mathematical and graphical operations. Once you create a variable, you can use it to create other variables.
If you don't see a description for an item in this window, check in the Shared items section near the front of the chapter.
This field contains the name of the variable you are creating. All variables must have their own, distinct name. Names can contain letters and numbers in any order, but there shouldn't be any "special" characters other than a dash or underscore.
This field contains the expression which creates the new variable. New variables are constructed from existing ones, either variables from the SILO file, or variables you previously created.
Expressions must be very specific. Because of this, they can become rather complicated. If you want to learn more about MeshTV expressions, see the defvar command in the MeshTV Command Line Interface Manual .
This option area indicates what type of variable is being created. There are five possibilities:
Constant
,
Material
,
Mesh
,
Scalar
, and
Vector
. You must specify the kind of variable you are creating so MeshTV will know how to generate and plot it.
The Constant , Material , Scalar , and Vector data types in MeshTV refer to values placed at either the zones or the nodes of a mesh. To MeshTV, variables created with these data types are equivalent to quad/ucd/point variables and materials in a SILO data file.
Constant : The values at all nodes/zones are the same value.
Material : Each zone has a material number associated with it. You can use this existing material to create a new material.
Scalar : Each node/zone has one scalar value associated with it.
Vector : Each node/zone has a 2D or 3D vector associated with it.
The Mesh data type refers to meshes. To MeshTV, meshes created with this data type are equivalent to quadmesh and pointmesh variables in a SILO data file.
Mesh : Mesh nodes are laid out in a logically rectangular fashion.