Ifird

Synopsis: ifird(integer) = integer

Number of the first dihedral angle belonging to the residue n.

The function returns the original index of the first (rotatable or fixed) dihedral angle that belongs to the residue with the given index, or the special value ifird(nr+1) = nd+1.

This function is useful, for instance, to construct a loop over all atoms of a given residue, i:

 do j ifird(i) ifird(i+1)-1
   print "Angle $dnam(idord(j)) of residue $rnam(i) $rnum(i)"
 end do