TICA on backbone atoms

[qasimpars]

Hi,

I am trying to do TICA on backbone atoms but I couldn't find the commands for that. Could please tell me how I can do the TICA only on backbone atoms? Do the following commands do the TICA on backbone torsions?

arrays = []
feat = pyemma.coordinates.featurizer(pdb)
feat.add_backbone_torsions()
data = pyemma.coordinates.load(files, features=feat)

Regards