From 54c788d74eb94e2680ad5eea1071e4cd475b2991 Mon Sep 17 00:00:00 2001
From: Tommaso Zugno <tommasozugno@gmail.com>
Date: Thu, 4 Jun 2020 19:18:46 +0200
Subject: [PATCH] spectrum: fix wrong usage of atan

---
 .../examples/three-gpp-channel-example.cc     | 18 +++++----------
 .../test/three-gpp-channel-test-suite.cc      | 22 ++++++-------------
 2 files changed, 12 insertions(+), 28 deletions(-)

diff --git a/src/spectrum/examples/three-gpp-channel-example.cc b/src/spectrum/examples/three-gpp-channel-example.cc
index 2ba7e8e2a..e21635c25 100644
--- a/src/spectrum/examples/three-gpp-channel-example.cc
+++ b/src/spectrum/examples/three-gpp-channel-example.cc
@@ -68,19 +68,11 @@ DoBeamforming (Ptr<NetDevice> thisDevice, Ptr<ThreeGppAntennaArrayModel> thisAnt
   // compute the azimuth and the elevation angles
   Angles completeAngle (bPos,aPos);
 
-  double posX = bPos.x - aPos.x;
-  double phiAngle = atan ((bPos.y - aPos.y) / posX);
-
-  if (posX < 0)
-    {
-      phiAngle = phiAngle + M_PI;
-    }
-  if (phiAngle < 0)
-    {
-      phiAngle = phiAngle + 2 * M_PI;
-    }
-
-  double hAngleRadian = fmod ((phiAngle + M_PI),2 * M_PI - M_PI); // the azimuth angle
+  double hAngleRadian = fmod (completeAngle.phi, 2.0 * M_PI); // the azimuth angle
+  if (hAngleRadian < 0)
+  {
+    hAngleRadian += 2.0 * M_PI;     
+  } 
   double vAngleRadian = completeAngle.theta; // the elevation angle
 
   // retrieve the number of antenna elements
diff --git a/src/spectrum/test/three-gpp-channel-test-suite.cc b/src/spectrum/test/three-gpp-channel-test-suite.cc
index 9d3440cdf..df1866841 100644
--- a/src/spectrum/test/three-gpp-channel-test-suite.cc
+++ b/src/spectrum/test/three-gpp-channel-test-suite.cc
@@ -402,28 +402,20 @@ ThreeGppSpectrumPropagationLossModelTest::~ThreeGppSpectrumPropagationLossModelT
 void
 ThreeGppSpectrumPropagationLossModelTest::DoBeamforming (Ptr<NetDevice> thisDevice, Ptr<ThreeGppAntennaArrayModel> thisAntenna, Ptr<NetDevice> otherDevice, Ptr<ThreeGppAntennaArrayModel> otherAntenna)
 {
-  uint8_t noPlane = 1;
   ThreeGppAntennaArrayModel::ComplexVector antennaWeights;
 
   Vector aPos = thisDevice->GetNode ()->GetObject<MobilityModel> ()->GetPosition ();
   Vector bPos = otherDevice->GetNode ()->GetObject<MobilityModel> ()->GetPosition ();
 
+  // compute the azimuth and the elevation angles
   Angles completeAngle (bPos,aPos);
 
-  double posX = bPos.x - aPos.x;
-  double phiAngle = atan ((bPos.y - aPos.y) / posX);
-
-  if (posX < 0)
-    {
-      phiAngle = phiAngle + M_PI;
-    }
-  if (phiAngle < 0)
-    {
-      phiAngle = phiAngle + 2 * M_PI;
-    }
-
-  double hAngleRadian = fmod ((phiAngle + (M_PI / noPlane)),2 * M_PI / noPlane) - (M_PI / noPlane);
-  double vAngleRadian = completeAngle.theta;
+  double hAngleRadian = fmod (completeAngle.phi, 2.0 * M_PI); // the azimuth angle
+  if (hAngleRadian < 0)
+  {
+    hAngleRadian += 2.0 * M_PI;     
+  } 
+  double vAngleRadian = completeAngle.theta; // the elevation angle
 
   int totNoArrayElements = thisAntenna->GetNumberOfElements ();
   double power = 1 / sqrt (totNoArrayElements);