I assume if you've successfully run a 2-phase particle run, that you've been using the Rocpart User's Guide for guidance? (http://illinoisrocstar.github.io/Rocstar/rocpart_ug.pdf) You should have output files described in Section 3.3.3 of that manual (<casename>.plag sola <region> <stamp>) assuming you're running Rocflu. You can write scripts/code to format those files for processing by your favorite plotting tool (see section 4.4 for the basic layout of the output files). It has been quite a while...