update find_peaks algorithm

This commit updates the find peaks algorithm with several improvements which
together drastically improve its ability to find Cerenkov rings:

- when computing the Hough transform, instead of charge we weight each PMT hit
  by the probability that it is a multi-photon PMT hit
- we don't subtract off previously found rings (this makes the code simpler and
  I don't think it previously had a huge effect)
- ignore PMT hits who are within approximately 5 degrees of any previously
  found ring (previously we ignored all hits within the center of previously
  found rings)
- ignore PMT hits which have a time residual of more than 10 nanoseconds to
  hopefully ignore more reflected and/or scattered light
- switch from weighting the Hough transform by exp(-fabs(cos(theta)-1/n)/0.1)
  -> exp(-pow(cos(theta)-1/n,2)/0.01). I'm still not sure if this has a huge
  effect, but the reason I switched is that the PDF for Cerenkov light looks
  closer to the second form.
- switch to calling quad with f = 1.0 in test-find-peaks (I still need to add
  this update to fit.c but will do that in a later commit).

1 files changed, 5 insertions, 2 deletions

diff --git a/src/find_peaks.h b/src/find_peaks.h
index 0219561..584774a 100644
--- a/src/find_peaks.h
+++ b/src/find_peaks.h
@@ -20,8 +20,11 @@
 #include "event.h"
 #include <stddef.h> /* for size_t */
 
+/* Maximum number of PE to consider when calculating P(> 1 hit|q) */
+#define FIND_PEAKS_MAX_PE 10
+
 void find_peaks_array(double *x, size_t n, size_t m, size_t *imax, size_t *jmax, size_t *npeaks, size_t max_peaks, double threshold);
-void get_hough_transform(event *ev, double *pos, double *x, double *y, size_t n, size_t m, double *result, double *last, size_t len);
-void find_peaks(event *ev, double *pos, size_t n, size_t m, double *peak_theta, double *peak_phi, size_t *npeaks, size_t max_peaks, double delta);
+void get_hough_transform(event *ev, double *pos, double t0, double *x, double *y, size_t n, size_t m, double *result, double *last, size_t len);
+void find_peaks(event *ev, double *pos, double t0, size_t n, size_t m, double *peak_theta, double *peak_phi, size_t *npeaks, size_t max_peaks, double delta);
 
 #endif