8FUNCTIONS: iar - CYANA function

Synopsis: iar(<integer>) = <integer>

This function returns the residue index of the atom with the given
atom index.

The residues are indexed from 1 to nr according to the sequence
declared in the sequence file. Note that the (external) residue number
that is used to identify a residue in the input files can be different
from the (internal) residue index. The function 'rnum' can be used
to obtain the external residue number of from the residue index.

Optionally, the <integer> atom index can be replaced by a string
consisting of the atom name and the residue number, separated by a
blank or a period, '.'.

See also: rnum
