Eumeration scheme for particle IDs (PIDs) of the dark matter particles in the initial conditions
Alexander Johnson
10 Mar
I would like to get details on the enumeration scheme for the dark matter (DM) particle PIDs; particularly for the DM only simulations. I'm running the DM only initial conditions and would like to be able to compute the lagrangian displacement of particles.
I should have mentioned that I would like to use the PIDs to calculate a "distance" between particles at any timestep with the idea that if the PIDs relate to some enumeration of the original particles on a lattice (during IC generation) then this "PID distance" actually still means something useful. The context is that I'm running a different simulation with the same initial conditions. Of course this will only be useful if the PIDs result from some structured enumeration of the particles over space so that this "PID distance" can be computed; this is important because I would be computing this PID distance for many particles at every time step and so indexing the IC file to try do something like this would be impractical.
Dylan Nelson
10 Mar
You can look at the N-GenIC source to get a sense of how the ParticleIDs correspond to the index ordering.
The TNG ICs are tiled glass configurations, so I don't think it is possible that the distance between any two particles in the ICs can be expressed solely as a function of their IDs.
I would like to get details on the enumeration scheme for the dark matter (DM) particle PIDs; particularly for the DM only simulations. I'm running the DM only initial conditions and would like to be able to compute the lagrangian displacement of particles.
Perhaps this thread is related.
To compute the displacement, you can calculate the distance between the current location of any DM particle, and its position in the ICs?
I should have mentioned that I would like to use the PIDs to calculate a "distance" between particles at any timestep with the idea that if the PIDs relate to some enumeration of the original particles on a lattice (during IC generation) then this "PID distance" actually still means something useful. The context is that I'm running a different simulation with the same initial conditions. Of course this will only be useful if the PIDs result from some structured enumeration of the particles over space so that this "PID distance" can be computed; this is important because I would be computing this PID distance for many particles at every time step and so indexing the IC file to try do something like this would be impractical.
You can look at the N-GenIC source to get a sense of how the ParticleIDs correspond to the index ordering.
The TNG ICs are tiled glass configurations, so I don't think it is possible that the distance between any two particles in the ICs can be expressed solely as a function of their IDs.