next up previous 264
Next: SinkFile - Output file to which to data should be written
Up: AST Attribute Descriptions
Previous: SimpIF - Inverse-forward MathMap pairs simplify?


SimpVertices - Simplify a Polygon by transforming its vertices?

Description:
This attribute controls the behaviour of the astSimplify method when applied to a Polygon. The simplified Polygon is created by transforming the vertices from the Frame in which the Polygon was originally defined into the Frame currently represented by the Polygon. If SimpVertices is non-zero (the default) then this simplified Polygon is returned without further checks. If SimpVertices is zero, a check is made that the edges of the new Polygon do not depart significantly from the edges of the original Polygon (as determined by the uncertainty associated with the Polygon). This could occur, for instance, if the Mapping frrm the original to the current Frame is highly non-linear. If this check fails, the original unsimplified Polygon is returned without change.
Type:
Integer (boolean).
Class Applicability:
Polygon
All Polygons have this attribute.


next up previous 264
Next: SinkFile - Output file to which to data should be written
Up: AST Attribute Descriptions
Previous: SimpIF - Inverse-forward MathMap pairs simplify?

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
25th February 2013
E-mail:starlink@jiscmail.ac.uk

Copyright (C) 2014 Science \& Technology Facilities Council