From c6b210c1defdd39b4fb68fb2ae8acb6076cf15b3 Mon Sep 17 00:00:00 2001
From: szepfalvibalint <60049889+szepfalvibalint@users.noreply.github.com>
Date: Sat, 18 Apr 2020 13:26:10 +0200
Subject: [PATCH] Mapping of phi to all 4 quadrants

I have tested it with a small number of Pythia8 data.
---
 pythiaplotter/parsers/event_classes.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pythiaplotter/parsers/event_classes.py b/pythiaplotter/parsers/event_classes.py
index 589125b..3da5294 100644
--- a/pythiaplotter/parsers/event_classes.py
+++ b/pythiaplotter/parsers/event_classes.py
@@ -153,7 +153,7 @@ def convert_px_py_pz(px, py, pz):
     p = math.sqrt(math.fsum([math.pow(pt, 2), math.pow(pz, 2)]))
     if pt != 0:
         eta = math.asinh(pz / pt)
-        phi = math.asin(py / pt)
+        phi = math.atan2(py, px)
     else:
         eta = math.copysign(float('inf'), pz)
         phi = 0