# CYANA Function: idord

## Synopsis

**idord( integer) = integer**

## Description

Given the index of a dihedral angle with respect to the original order of dihedral angles, this function returns its actual dihedral angle index.

Optionally, the *integer* dihedral angle index can be replaced by a
string consisting of the dihedral angle name and the residue number,
separated by a blank or a period, **.**.

The original indexing 1,...,nd of the dihedral angles is made according
to the the order of the dihedral angles in the residue library and of
the residues in the sequence. When the tree structure of the rotatable
dihedral angles is set up upon reading the sequence or executing the
**angles fix** or **angles free** commands, this original order is modified
such that the rotatable dihedral angles 1,...,ndfree precede the fixed
dihedral angles ndfree+1,...,nd. This becomes the standard ordering
of the dihedral angles.