[gmx-users] makes sense for Ryckaert Bellemans dihs. only.

[Sadaf Rani]

Dear Gromacs users

I am calculating a dihedral angle between certain atoms by following
command:-

gmx angle -type dihedral -f md_1000ps.xtc -n dihedral.ndx -ov group.xvg -of
trans.xvg

Group     0 (      dihedral1) has     4 elements
Group     1 (      dihedral2) has     4 elements
Group     2 (      dihedral3) has     4 elements
Select a group: 2
Selected 2: 'dihedral3'
I get a warning as below:-
Warning: calculating fractions as defined in this program
makes sense for Ryckaert Bellemans dihs. only. Ignoring -of

What does it mean? Can anyone please help me to understand? I am using
gromacs 2020

Thanks.
Sadaf