Green-Kubo

Hi all,
I am trying to calculate thermal conductivity using Green-Kubo based on LAMMPS input script for thermal conductivity of solid Ar. I have obtained the J0Jt.dat file. How can I obtain the curve for HCACF (heat current autocorrelation function)?

Thank you,
Tony

The format of files generated by fix ave/correlate is described on its doc page in the manual: fix ave/correlate command — LAMMPS documentation