add a couple of improvements to the quad fitter and fix a bug in get_hough_transform()

This commit adds two improvements to the quad fitter:

1. I updated quad to weight the random PMT hit selection by the probability
that the PMT hit is a multiphoton hit. The idea here is that we really only
want to sample direct light and for high energy events the reflected and
scattered light is usually single photon.

2. I added an option to quad to only use points in the quad cloud which are
below a given quantile of t0. The idea here is that for particles like muons
which travel more than a few centimeters in the detector the quad cloud usually
looks like the whole track. Since we want the QUAD fitter to find the position
of the *start* of the track we select only those quad cloud points with an
early time so the position is closer to the position of the start of the track.

Also, I fixed a major bug in get_hough_transform() in which I was using the
wrong index variable when checking if a PMT was not flagged, a normal PMT, and
was hit. This was causing the algorithm to completely miss finding more than
one ring while I was testing it.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/Makefile b/src/Makefile
index 7787558..cb701cb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -32,9 +32,9 @@ test-time-pdf: test-time-pdf.o zebra.o likelihood.o pmt.o vector.o misc.o muon.o
 
 test-zebra: test-zebra.o zebra.o pack2b.o
 
-fit: fit.o zebra.o likelihood.o pmt.o vector.o misc.o muon.o optics.o quantum_efficiency.o solid_angle.o pdg.o scattering.o zdab_utils.o pack2b.o sno_charge.o db.o dqxx.o dict.o siphash.o path.o pmt_response.o release.o electron.o proton.o find_peaks.o quad.o dc.o sort.o util.o hdf5_utils.o
+fit: fit.o zebra.o likelihood.o pmt.o vector.o misc.o muon.o optics.o quantum_efficiency.o solid_angle.o pdg.o scattering.o zdab_utils.o pack2b.o sno_charge.o db.o dqxx.o dict.o siphash.o path.o pmt_response.o release.o electron.o proton.o find_peaks.o quad.o dc.o sort.o util.o hdf5_utils.o random.o mt19937ar.o
 
-test-find-peaks: test-find-peaks.o zebra.o likelihood.o pmt.o vector.o misc.o muon.o optics.o quantum_efficiency.o solid_angle.o pdg.o scattering.o zdab_utils.o pack2b.o sno_charge.o db.o dqxx.o dict.o siphash.o path.o pmt_response.o release.o electron.o proton.o find_peaks.o util.o quad.o
+test-find-peaks: test-find-peaks.o zebra.o likelihood.o pmt.o vector.o misc.o muon.o optics.o quantum_efficiency.o solid_angle.o pdg.o scattering.o zdab_utils.o pack2b.o sno_charge.o db.o dqxx.o dict.o siphash.o path.o pmt_response.o release.o electron.o proton.o find_peaks.o util.o quad.o random.o mt19937ar.o
 
 calculate-csda-range: calculate-csda-range.o