From 45aeb35aa99e9ea80c58ebe8f356a50b8e729cac Mon Sep 17 00:00:00 2001
From: Sterling Harper <smharper@mit.edu>
Date: Tue, 24 Sep 2019 15:15:30 -0400
Subject: [PATCH] Rotate azimuthal distributions by pi/2

---
 src/distribution_multi.cpp                     | 4 ++--
 tests/regression_tests/source/results_true.dat | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/distribution_multi.cpp b/src/distribution_multi.cpp
index d4a728c71f..0c1ecddecb 100644
--- a/src/distribution_multi.cpp
+++ b/src/distribution_multi.cpp
@@ -59,8 +59,8 @@ Direction PolarAzimuthal::sample() const
   double mu = mu_->sample();
   if (mu == 1.0) return u_ref_;
 
-  // Sample azimuthal angle
-  double phi = phi_->sample();
+  // Sample the azimuthal angle with an offset to match azimuth conventions
+  double phi = phi_->sample() + 0.5*PI;
   return rotate_angle(u_ref_, mu, &phi);
 }
 
diff --git a/tests/regression_tests/source/results_true.dat b/tests/regression_tests/source/results_true.dat
index 90cc3ec1f6..6fe76c8cd5 100644
--- a/tests/regression_tests/source/results_true.dat
+++ b/tests/regression_tests/source/results_true.dat
@@ -1,2 +1,2 @@
 k-combined:
-3.026614E-01 3.952008E-03
+2.800827E-01 7.360163E-03