advanced fragment information

Fragments are defined as series of amino-acids that are covalently bonded, and are not bonded to other fragments.
A series of methods are related to their detection. The generic method is frgList.
Usage:
frgList(maxNCDist = 1.7, maxCADist = 4.1)
This will return the number of fragments detected, and their boundaries (numbered from 0). This method will detect fragments onthe basis of the inter-atomic distance between the C' atoms of residue $k$ and the N atom of residue $k+1$. If only the CA atoms are provided, the distance between the consecutive alpha-carbons will be used instead. If not specified, the default inter-atomic distance provided are of 1.7 and 4.1. The values were chosen since found to encompass much of the PDB deviations to standard geometry. They can be modified as any named parameter.

The more advanced methods wrapped by frgList are: chnCAFrgList() (for CA fragments) and chnFrgList() (for all atom fragments).

The nFrg() method will only return the number of fragments.