#### Description:

This attribute controls which one of a Mapping `’` s two possible coordinate transformations is considered the `"` forward`"` transformation (the other being the `"` inverse`"` transformation). If the attribute value is zero (the default), the Mapping`’` s behaviour will be the same as when it was first created. However, if it is non-zero, its two transformations will be inter-changed, so that the Mapping displays the inverse of its original behaviour.

Inverting the boolean sense of the Invert attribute will cause the values of a Mapping`’` s Nin and Nout attributes to be interchanged. The values of its TranForward and TranInverse attributes will also be interchanged. This operation may be performed with the astInvert function.

Type:

  Integer (boolean).

#### Applicability

##### Mapping

All Mappings have this attribute.

##### UnitMap

The value of the Invert attribute has no effect on the behaviour of a UnitMap.

##### FrameSet

Inverting the boolean sense of the Invert attribute for a FrameSet will cause its base and current Frames (and its Base and Current attributes) to be interchanged. This, in turn, may affect other properties and attributes of the FrameSet (such as Nin, Nout, Naxes, TranForward, TranInverse, etc.). The Invert attribute of a FrameSet is not itself affected by selecting a new base or current Frame.
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