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Nout - Number of output coordinates for a Mapping

Description:
This attribute gives the number of coordinate values generated by a Mapping to specify each output point (i.e. the number of dimensions of the space in which the Mapping's output points reside).
Type:
Integer, read-only.
Class Applicability:
Mapping
All Mappings have this attribute.
CmpMap
If a CmpMap's component Mappings are joined in series, then its Nout attribute is equal to the Nout attribute of the second component (or to the Nin attribute of the first component if the the CmpMap's Invert attribute is non-zero).

If a CmpMap's component Mappings are joined in parallel, then its Nout attribute is given by the sum of the Nout attributes of each component (or to the sum of their Nin attributes if the CmpMap's Invert attribute is non-zero).

Frame
The Nout attribute for a Frame is always equal to the number of Frame axes (Naxes attribute).
FrameSet
The Nout attribute of a FrameSet is equal to the number of FrameSet axes (Naxes attribute) which, in turn, is equal to the Naxes attribute of the FrameSet's current Frame (as specified by the Current attribute). The Nout attribute value may therefore change if a new current Frame is selected.


next up previous 264
Next: Nparameter - The number of global parameters in the table
Up: AST Attribute Descriptions
Previous: NormUnit(axis) - Normalised Axis physical units

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council