Get Vertex Values of Function: getv3

Calling Sequence

...

  
getv3(i, m3, chunk) 
getv3_rect(i, m3, chunk) 
getv3_irreg (i, m3, chunk)

Description

getv3 returns vertex values of the I th function attached to 3D mesh M3 for cells in the specified CHUNK. The CHUNK may be a list of cell indices, in which case getv3 returns a 2x2x2x(CHUNK. shape) list of vertex coordinates. CHUNK may also be a mesh-specific data structure used in the slice3 routine (see ``slice3: Plane and Isosurface Slices of a 3D mesh'' on page ), in which case getv3 may return a (ni) x(nj) x(nk) array of vertex values. For meshes which are logically rectangular or consist of several rectangular patches, this is up to 8 times less data, with a concomitant performance advantage. Use getv3 when writing slicing functions for slice3.

getv3_rect does the job for a regular rectangular mesh. getv3_irreg, for an irregular mesh, returns a 3-list whose elements are:

1. the function values for the I th function on the vertices of the given CHUNK. (The function values must have the same dimension as the coordinates; there is no attempt to convert zone-centered values to vertex-centered values.)

2. an array of relative cell numbers within the list of cells of this type.

3. a number that can be added to these relative numbers to give the absolute cell numbers for correct access to their coordinates and function values