[clsim] coalesce PEs

[David Schultz]

from comment:7:ticket:1322

It would also be nice to have an option to coalesce MCPEs that are within, say, 200 ps of each other, which is the same binning that PMTResponseSimulator uses in its "don't use all the memory in the universe" mode.

For an example 200 PeV numu interaction inside Gen2, doing that after the fact reduces the number of discrete MCPEs by a factor of 40. That would still leave a large number of I3Photons floating around; to handle those you would need a service-like analogue to I3PhotonToMCPEConverter that operates on batches of I3Photons as they come back from the GPU, converting them to MCPEs and coalescing with existing MCPEs from previous batches. All of this destroys the connection between PE and source particle, but I think that's a price we'll have to pay.

[Jakob van Santen]

This is also implemented in clsim/branches/multiprocess-server

[Alex Olivas]

Since this is solved on the multiprocess-server branch, I'm closing this as a duplicate of ticket #2160. That merge will happen soon-ish, at least in the next few months.

[Alex Olivas]

Milestone Winter Solstice 2018 deleted