Cross check: Travel distance to absorption with medium boundary

[fiedl]

Scenario: Start several photons towards the hole-ice cylinder as a pencil beam. Choose the absorption length outside and inside to be different.

Expectation: The distribution of the travelled distance of each photon should follow a piecewise overlay of two exponential curves.

Other cross checks: https://github.com/fiedl/hole-ice-study/issues/63

[fiedl]

For this cross check, deactivate ice layers and set the scattering length outside to a different value than inside the hole ice.

// clsim/resources/kernels/lib/propagation_through_media/propagation_through_media.c

// Ice properties outside the hole ice:
floating_t local_scattering_lengths[MEDIUM_LAYERS] = {1000000.0};
floating_t local_absorption_lengths[MEDIUM_LAYERS] = {1.0};

// add_ice_layers_on_photon_path_to_medium_changes(...) // commented out

Running the cross check simulation locally:

[2018-05-14 17:56:59] fiedl@fiedl-mbp ~/hole-ice-study/scripts/FiringRange master ⚡

# Ice properties inside the hole ice:
rm tmp/gcd_with_hole_ice.i3
./run.rb \
    --hole-ice-radius=1.00 \
    --effective-scattering-length=100.0 \
    --absorption-length=0.10 \
    --distance=2.0 \
    --number-of-photons=100000 \
    --cpu --save-photon-paths \
    --number-of-runs=1 --number-of-parallel-runs=1 \
    |grep "CROSS CHECK" |grep -v "INFO" \
    > ~/hole-ice-study/results/cross_checks/cross_check_65.txt
steamshovel tmp/propagated_photons.i3

[fiedl]

Running the plot and fit script:

[2018-05-14 21:33:43] fiedl@fiedl-mbp ~/hole-ice-study/scripts/lib master ⚡
▶ ./plot_cross_check_photonTotalPathLength_distribution_with_medium_boundary.py
[4.38093716e+03   1.59597602e+04   9.85225373e-01   9.85381640e+00]

[fiedl]

Looks good.

[fiedl]

Fixing plot labels:

[fiedl]

adding parameter errors to plot:

[fiedl]

Some open questions:

• [ ] Why is the error of the first fit parameter (lambda 1) so large?
• [ ] Why is there a half-height bin at x = 1.0?