ARCA: TIme Residual Plot

The Time residual plot for ARCA shows asymmetric distribution. This is expected to be due to scattering photons, but the sign is opposite (at least it seems). Can Tom please check?

Thanks for reporting. I am already checking...

So in https://git.km3net.de/km3py/km3mon/blob/master/scripts/live_royfit.jl#L83 the time residual is calculated via:

for hit in hits
    Δt = hit.t - ccalc(hit.pos.z)
    write(fobj, "$(event.run_id),$(event.timestamp),$(hit.du),$(hit.floor),$(hit.dom_id),$(Δt),$(fit.Q)\n")
end

Then the time_residuals.py is used to do the actual plotting and it looks like I put in a minus sign: https://git.km3net.de/km3py/km3mon/blob/master/scripts/time_residuals.py#L56

for du in np.unique(df.du):
    _df = df[df.du == du]
    t_res = _df[_df.floor == floor].t_res
    t_res = t_res[np.abs(t_res) < 500]
    print(f"   DU {du} floor {floor}: {len(t_res)} entries")
    ax.hist(-t_res,
            bins=100,
            histtype='step',
            lw=2,
            label=f'Floor {floor} / DU {du}')

For whatever reason ;)

closed via commit c9f469e6

Looks better now: