Create a PermMap
A PermMap is a Mapping which permutes the order of coordinates, and possibly also changes the number of coordinates, between its input and output.
In addition to permuting the coordinate order, a PermMap may also assign constant values to coordinates. This is useful when the number of coordinates is being increased as it allows fixed values to be assigned to any new ones.
For details of additional special values that may be used in this array, see the description of the CONSTANT argument.
For details of additional special values that may be used in this array, see the description of the CONSTANT argument.
Care should be taken to ensure that locations lying outside the extent of this array are not accidentally addressed. The array is not used if the INPERM and OUTPERM arrays do not contain negative values.
If either of the INPERM or OUTPERM arrays contains a zero value (or a positive value which does not identify a valid output/input coordinate, as appropriate), then the value AST__BAD is assigned as the new coordinate value.
This function does not attempt to ensure that the forward and inverse transformations performed by the PermMap are self-consistent in any way. You are therefore free to supply coordinate permutation arrays that achieve whatever effect is desired.
A null Object pointer (AST__NULL) will be returned if this function is invoked with STATUS set to an error value, or if it should fail for any reason.