casacore
Modules | Classes

Lattice expressions. More...

Modules

 LEL_module_internal_classes
 Internal LEL_module classes and functions.
 

Classes

class  casacore::LatticeExpr< T >
 Class to allow C++ expressions involving lattices. More...
 
class  casacore::LatticeExprNode
 Bridging class to allow C++ expressions involving lattices. More...
 
class  casacore::LELCoordinates
 Envelope class to handle Lattice Coordinates in LEL. More...
 

Detailed Description

Lattice expressions.

See below for an overview of the classes in this module.

Prerequisite

Review Status

Reviewed By:
Peter Barnes
Date Reviewed:
1999/10/30

Etymology

LEL: Lattice Expression Language.

Synopsis

A LatticeExpr represents a mathematical expression of lattices. All standard operators, regions, and many, many functions can be used in an expression.
An expression is calculated on-the-fly. Thus only when the user gets a part of the lattice, is the expression calculated for that part. Subexpressions resulting in a scalar are calculated only once, on a get of the first part of the lattice expression.
Note that a lattice expression is not writable, thus using the put function on such a lattice results in an exception.
Note 223 gives a more detailed explanation of the capabilities of LEL (Lattice Expression Language).

If the expression consists of images, the result can also be treated as an image using class ImageExpr . With the command function in ImageExprParse it is possible to parse and execute a LEL expression given as as a string.