’ 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 AST_INVERT routine.