From: Ashar Malik (
Date: Mon Oct 23 2017 - 02:05:30 CDT

Technically you don't need the entire trajectory loaded to carry out what
you want to do.
Load it in manageable portions.

For example use first 0 last 100 step 1 to load the first 100 or however
many frames you want.
When you are done with those. use the next 100 by changing the first and
last flags appropriately.
To do the same using the GUI -- use the First and Last boxes which become
active when you select a trajectory for loading.
You can write out a few trajectories and then concatenate them using catdcd.
I think there is another way of doing this as well but I can't recall it at
the moment.
I am assuming that was the problem and not usage of animate.
If this doesn't help write back.

On Mon, Oct 23, 2017 at 7:24 PM, Monika Madhavi <>

> Hi everyone,
> I have a huge dcd file from which I need to write an atom selection to a
> separate dcd file. I need to update the selection every frame as well. To
> do this with animate write, I can't load the entire trajectory first as i
> don't have enough memory. Can someone please suggest a way to do this?
> Thank you.
> Best regards,
> Monika
> --
> W.A.Monika Madhavi
> Lecturer (Probation),
> Department of Physics,
> University of Colombo.