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Output Data from Replica_exchange.py

Open covo6734 opened this issue 5 years ago • 6 comments

The data produced by examples/replica_exchange/replica_exchange.py may be repeating instead of generating new data as the parameters are varied. The constants for bond_angle_force_constant and torsion_force_constant have been brought from 0.5 all the day down to 0.001 with no noticeable change on the output .pdb files. Additionally, the graphical output for the Replica Exchange Simulation shows nearly identical results for the energy values regardless of what these constant values are set to. This seems to indicate the simulation is not accounting for these constants, or resetting them before each run. Changing the temperature ranges also seems to have little to no effect on these outputs.

covo6734 avatar Jan 24 '20 21:01 covo6734

What version of yank are you using? I'm having issues running it with Yank 0.20.1?

mrshirts avatar Feb 04 '20 23:02 mrshirts

The yank on the computer I've been running from is Yank 0.21.2

covo6734 avatar Feb 05 '20 00:02 covo6734

So, I have updated Yank to 0.25.2, and am getting a No module named 'yank.multistate' error. Since Yank is getting updated, my current plan is to debug in Yank 0.25.2, and then have other people update yank. Does that make sense?

mrshirts avatar Feb 06 '20 19:02 mrshirts

OK, I have the example running. I've posted the changes I needed to make with up-to-date libraries in branch mrs_tweak_feb2020. But very strange that the energy is so low for all attempts - seems to be of order `10^-19 (are energy off by a factor of N_avogadro), and the positions are moving quite slowly for that number of steps I'll keep poking around with this - perhaps a unit conversion error hidden somewhere?

mrshirts avatar Feb 11 '20 06:02 mrshirts

I checked and did not find any unit conversion errors. It does appear that energy only varies with temperature and not the torsion_force_constant or the bond_angle_force_constant. The output of the rep_ex_ener.png graph only changes in regards to temperature.

covo6734 avatar Feb 12 '20 22:02 covo6734

Interesting, so the model may not be including those things. I'll keep poking.

mrshirts avatar Feb 13 '20 03:02 mrshirts