### Iwc

Include a Frame representing FITS-WCS intermediate world coordinates?

#### Description:

This attribute is a boolean value which is used when a FrameSet is read from a FitsChan with a foreign FITS encoding (e.g. FITS-WCS) using astRead. If it has a non-zero value then the returned FrameSet will include Frames representing " intermediate world coordinates" (IWC). These Frames will have Domain name " IWC" for primary axis descriptions, and " IWCa" for secondary axis descriptions, where " a" is replaced by the single alternate axis description character, as used in the FITS-WCS header. The default value for " Iwc" is zero.

FITS-WCS paper 1 defines IWC as a Cartesian coordinate system with one axis for each WCS axis, and is the coordinate system produced by the rotation matrix (represented by FITS keyword PCi_j, CDi_j, etc). For instance, for a 2-D FITS-WCS header describing projected celestial longitude and latitude, the intermediate world coordinates represent offsets in degrees from the reference point within the plane of projection.

Type:
Integer (boolean).

#### Applicability

##### FitsChan
All FitsChans have this attribute.