2D grids: definition (structure)
Definition
A 2D grid is defined by:
 a name (and a comment)
 a type
 a coordinate system for definition
 an origin (in a coordinate system for definition)
 specific characteristics belonging to a type
 a coordinate system for definition
 attributes of color and visibility
Name
The name to identify the 2D grid is set by the user during the creation of this one.
A comment (optional) can be added to the name.
Type of 2D grids
The different types of 2D grids and the characteristics useful for their description are presented in the table below.
Type  Characteristics  

All types  2D grid origin coordinates  coordinate system for definition 
Type  Characteristics  

Rectangular in the XY plane 
dimension along positive X dimension along negative X number of elements along X 
dimension along positive Y dimension along negative Y number of elements along Y 

Rectangular in the XZ plane 
dimension along positive X dimension along negative X number of elements along X 
dimension along positive Z dimension along negative Z number of elements along Z 

Rectangular in the YZ plane 
dimension along positive Y dimension along negative Y number of elements along Y 
dimension along positive Z dimension along negative Z number of elements along Z 

Annular 
internal radius external radius number of elements along the radius 
minimal θ maximal θ number of elements along θ 

Cylindrical  radius 
minimal θ maximal θ number of elements along the radius 
dimension along positive Z dimension along negative Z number of elements along Z 
Spherical  radius 
minimal θ maximal θ number of elements along the radius 
minimal φ maximal φ number of elements along φ 
Length and angle units
Length and angle units are those associated with the coordinate system.