ordering.HPDataFrame: HEALPix ordering scheme from a HPDataFrame
Description
This function returns the HEALPix ordering scheme from a HPDataFrame.
The ordering scheme is either "ring" or "nested". If a new ordering
is specified, using e.g. new.ordering = "ring", the
ordering scheme of the HPDataFrame will be converted.
Usage
# S3 method for HPDataFrame
ordering(x, new.ordering, ...)