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| author | tlatorre <tlatorre@uchicago.edu> | 2019-08-26 10:25:41 -0500 |
|---|---|---|
| committer | tlatorre <tlatorre@uchicago.edu> | 2019-08-26 10:25:41 -0500 |
| commit | d319be4e9710a4c87a6217ba0a7b06a73b9e65cc (patch) | |
| tree | e5a3dc708986b7a8564412fb370567b8a650fd49 /src | |
| parent | 6dd68960212773f54dc56273f811b88e2bac5b09 (diff) | |
| download | sddm-d319be4e9710a4c87a6217ba0a7b06a73b9e65cc.tar.gz sddm-d319be4e9710a4c87a6217ba0a7b06a73b9e65cc.tar.bz2 sddm-d319be4e9710a4c87a6217ba0a7b06a73b9e65cc.zip | |
fix a bug in get_{shower,delta_ray}_weights() causing crash
This commit fixes a bug in get_shower_weights() and get_delta_ray_weights()
which was causing an inf value to propagate and cause the fitter to crash. The
problem came because due to floating point roundoff the cdf value at the end of
the loop was slightly greater than the last cdf value we wanted which was
causing it to get mapped to cos(theta) = -1 (I think?) and then subsequently
get interpolated to an infinite value for xcdf.
The fix is just to make sure that the x coordinate is always between x1 and x2.
Diffstat (limited to 'src')
| -rw-r--r-- | src/likelihood.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/likelihood.c b/src/likelihood.c index 4a0e755..5ca9c8d 100644 --- a/src/likelihood.c +++ b/src/likelihood.c @@ -358,6 +358,13 @@ int get_delta_ray_weights(particle *p, double range, double distance_to_psup, do cdf = cdf1 + i*delta; cos_theta = gsl_spline_eval(p->spline_delta,cdf,p->acc_delta); xcdf = cos_theta_to_x(cos_theta,R,cos_gamma,sin_gamma); + + /* Occasionally due to floating point rounding error, it's possible + * that cdf > cdf2 and so we end up with xcdf = inf. To prevent this, + * we just make sure that xcdf is bounded by x1 and x2. */ + if (xcdf < x1) xcdf = x1; + if (xcdf > x2) xcdf = x2; + if (i > 0) { /* For each interval we approximate the integral as: * @@ -442,6 +449,13 @@ int get_shower_weights(particle *p, double distance_to_psup, double *x, double * cdf = cdf1 + i*delta; cos_theta = gsl_spline_eval(p->spline_shower,cdf,p->acc_shower); xcdf = cos_theta_to_x(cos_theta,R,cos_gamma,sin_gamma); + + /* Occasionally due to floating point rounding error, it's possible + * that cdf > cdf2 and so we end up with xcdf = inf. To prevent this, + * we just make sure that xcdf is bounded by x1 and x2. */ + if (xcdf < x1) xcdf = x1; + if (xcdf > x2) xcdf = x2; + if (i > 0) { /* For each interval we approximate the integral as: * |