This attribute specifies the largest legal index for a PV projection parameter attached to a specified axis of the WcsMap (i.e. the largest legal value for " m" when accessing the "PVi_m" attribute). The axis index is specified by i, and should be in the range 1 to 99. The value for each axis is determined by the projection type specified when the WcsMap is first created using AST_WCSMAP and cannot subsequently be changed.

WcsMap