From ccfd018de9351d14577bdbd1f746fdffe77b7236 Mon Sep 17 00:00:00 2001
From: Moritz Kiehn <msmk@cern.ch>
Date: Fri, 10 Mar 2017 08:16:52 +0100
Subject: [PATCH] Surfaces: remove FastArcTan
---
Core/include/ACTS/Surfaces/BoundaryCheck.hpp | 25 -------------------
Core/include/ACTS/Surfaces/CylinderBounds.hpp | 7 +++---
Core/include/ACTS/Surfaces/DiamondBounds.hpp | 7 +++---
.../ACTS/Surfaces/DiscTrapezoidalBounds.hpp | 5 ++--
Core/include/ACTS/Surfaces/LineBounds.hpp | 7 +++---
Core/include/ACTS/Surfaces/RadialBounds.hpp | 15 ++++++-----
.../include/ACTS/Surfaces/RectangleBounds.hpp | 5 ++--
.../include/ACTS/Surfaces/TrapezoidBounds.hpp | 2 +-
Core/include/ACTS/Surfaces/TriangleBounds.hpp | 5 ++--
Tests/Surfaces/BoundaryCheckTests.cpp | 14 -----------
10 files changed, 23 insertions(+), 69 deletions(-)
diff --git a/Core/include/ACTS/Surfaces/BoundaryCheck.hpp b/Core/include/ACTS/Surfaces/BoundaryCheck.hpp
index 9dca2be13..fb2621b92 100644
--- a/Core/include/ACTS/Surfaces/BoundaryCheck.hpp
+++ b/Core/include/ACTS/Surfaces/BoundaryCheck.hpp
@@ -125,9 +125,6 @@ public:
bool
TestKDOPKDOP(std::vector<KDOP>& a, std::vector<KDOP>& b) const;
- double
- FastArcTan(double x) const;
-
sincosCache
FastSinCos(double x) const;
@@ -137,28 +134,6 @@ private:
static double s_cos67;
};
-/// should have maximum (average) error of 0.0015 (0.00089) radians or 0.0859
-/// (0.0509) degrees, fine for us and much faster (>4 times)
-inline double
-BoundaryCheck::FastArcTan(double x) const
-{
- double y;
- bool complement = false; // true if arg was >1
- bool sign = false; // true if arg was < 0
- if (x < 0.) {
- x = -x;
- sign = true; // arctan(-x)=-arctan(x)
- }
- if (x > 1.) {
- x = 1. / x; // keep arg between 0 and 1
- complement = true;
- }
- y = M_PI_4 * x - x * (std::abs(x) - 1) * (0.2447 + 0.0663 * std::abs(x));
- if (complement) y = M_PI_2 - y; // correct for 1/x if we did that
- if (sign) y = -y; // correct for negative arg
- return y;
-}
-
/// should have maximum (average) error of 0.001 (0.0005) radians or 0.0573
/// (0.029) degrees, fine for us and much faster (>8 times)
inline sincosCache
diff --git a/Core/include/ACTS/Surfaces/CylinderBounds.hpp b/Core/include/ACTS/Surfaces/CylinderBounds.hpp
index db2f8e166..7136528b2 100644
--- a/Core/include/ACTS/Surfaces/CylinderBounds.hpp
+++ b/Core/include/ACTS/Surfaces/CylinderBounds.hpp
@@ -215,10 +215,9 @@ CylinderBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
float theta
= ((*bcheck.lCovariance)(1, 0) != 0
&& ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)) != 0)
- ? .5
- * bcheck.FastArcTan(
- 2 * (*bcheck.lCovariance)(1, 0)
- / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
+ ? .5 * std::atan(
+ 2 * (*bcheck.lCovariance)(1, 0)
+ / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
: 0.;
sincosCache scResult = bcheck.FastSinCos(theta);
double dphi = scResult.sinC * scResult.sinC * (*bcheck.lCovariance)(0, 0);
diff --git a/Core/include/ACTS/Surfaces/DiamondBounds.hpp b/Core/include/ACTS/Surfaces/DiamondBounds.hpp
index 06e971c3a..c4feed579 100644
--- a/Core/include/ACTS/Surfaces/DiamondBounds.hpp
+++ b/Core/include/ACTS/Surfaces/DiamondBounds.hpp
@@ -275,10 +275,9 @@ DiamondBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
float theta
= ((*bcheck.lCovariance)(1, 0) != 0
&& ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)) != 0)
- ? .5
- * bcheck.FastArcTan(
- 2 * (*bcheck.lCovariance)(1, 0)
- / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
+ ? .5 * std::atan(
+ 2 * (*bcheck.lCovariance)(1, 0)
+ / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
: 0.;
auto rotMatrix = Eigen::Rotation2D<double>(theta).toRotationMatrix();
ActsMatrixD<2, 2> normal;
diff --git a/Core/include/ACTS/Surfaces/DiscTrapezoidalBounds.hpp b/Core/include/ACTS/Surfaces/DiscTrapezoidalBounds.hpp
index 3b9e30280..520c9ea70 100644
--- a/Core/include/ACTS/Surfaces/DiscTrapezoidalBounds.hpp
+++ b/Core/include/ACTS/Surfaces/DiscTrapezoidalBounds.hpp
@@ -402,9 +402,8 @@ DiscTrapezoidalBounds::inside(const Vector2D& lpos,
double y0 = 0;
float theta = (lCovarianceCar(1, 0) != 0
&& (lCovarianceCar(1, 1) - lCovarianceCar(0, 0)) != 0)
- ? .5
- * bcheck.FastArcTan(2 * lCovarianceCar(1, 0)
- / (lCovarianceCar(1, 1) - lCovarianceCar(0, 0)))
+ ? .5 * std::atan(2 * lCovarianceCar(1, 0)
+ / (lCovarianceCar(1, 1) - lCovarianceCar(0, 0)))
: 0.;
auto rotMatrix = Eigen::Rotation2D<double>(theta).toRotationMatrix();
Vector2D tmp = rotMatrix * (-lposCar);
diff --git a/Core/include/ACTS/Surfaces/LineBounds.hpp b/Core/include/ACTS/Surfaces/LineBounds.hpp
index 6e06c1feb..010ee69d8 100644
--- a/Core/include/ACTS/Surfaces/LineBounds.hpp
+++ b/Core/include/ACTS/Surfaces/LineBounds.hpp
@@ -163,10 +163,9 @@ LineBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
float theta
= ((*bcheck.lCovariance)(1, 0) != 0
&& ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)) != 0)
- ? .5
- * bcheck.FastArcTan(
- 2 * (*bcheck.lCovariance)(1, 0)
- / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
+ ? .5 * std::atan(
+ 2 * (*bcheck.lCovariance)(1, 0)
+ / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
: 0.;
sincosCache scResult = bcheck.FastSinCos(theta);
double dphi = scResult.sinC * scResult.sinC * (*bcheck.lCovariance)(0, 0);
diff --git a/Core/include/ACTS/Surfaces/RadialBounds.hpp b/Core/include/ACTS/Surfaces/RadialBounds.hpp
index 736614e97..ecfc1dd18 100644
--- a/Core/include/ACTS/Surfaces/RadialBounds.hpp
+++ b/Core/include/ACTS/Surfaces/RadialBounds.hpp
@@ -358,15 +358,14 @@ RadialBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
double y0 = 0;
float theta = (lCovarianceCar(1, 0) != 0
&& (lCovarianceCar(1, 1) - lCovarianceCar(0, 0)) != 0)
- ? .5
- * bcheck.FastArcTan(2 * lCovarianceCar(1, 0)
- / (lCovarianceCar(1, 1) - lCovarianceCar(0, 0)))
+ ? .5 * std::atan(2 * lCovarianceCar(1, 0)
+ / (lCovarianceCar(1, 1) - lCovarianceCar(0, 0)))
: 0.;
- auto rotMatrix = Eigen::Rotation2D<double>(theta).toRotationMatrix();
- Vector2D tmp = rotMatrix * (-lposCar);
- double x1 = tmp(0, 0);
- double y1 = tmp(1, 0);
- double r = m_valueStore[RadialBounds::bv_rMax];
+ auto rotMatrix = Eigen::Rotation2D<double>(theta).toRotationMatrix();
+ Vector2D tmp = rotMatrix * (-lposCar);
+ double x1 = tmp(0, 0);
+ double y1 = tmp(1, 0);
+ double r = m_valueStore[RadialBounds::bv_rMax];
// check if ellipse and circle overlap and return result
return test.collide(x0, y0, w, h, x1, y1, r);
}
diff --git a/Core/include/ACTS/Surfaces/RectangleBounds.hpp b/Core/include/ACTS/Surfaces/RectangleBounds.hpp
index 63a41a893..f0fa736bc 100644
--- a/Core/include/ACTS/Surfaces/RectangleBounds.hpp
+++ b/Core/include/ACTS/Surfaces/RectangleBounds.hpp
@@ -175,9 +175,8 @@ RectangleBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
= ((*bcheck.lCovariance)(1, 0) != 0
&& ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)) != 0)
? .5
- * bcheck.FastArcTan(
- 2 * (*bcheck.lCovariance)(1, 0)
- / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
+ * std::atan(2 * (*bcheck.lCovariance)(1, 0)
+ / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
: 0.;
auto rotMatrix = Eigen::Rotation2D<double>(theta).toRotationMatrix();
// ellipse is always at (0,0), surface is moved to ellipse position and then
diff --git a/Core/include/ACTS/Surfaces/TrapezoidBounds.hpp b/Core/include/ACTS/Surfaces/TrapezoidBounds.hpp
index 0f5370bb0..9e2355ff2 100644
--- a/Core/include/ACTS/Surfaces/TrapezoidBounds.hpp
+++ b/Core/include/ACTS/Surfaces/TrapezoidBounds.hpp
@@ -326,7 +326,7 @@ TrapezoidBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
= ((*bcheck.lCovariance)(1, 0) != 0
&& ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)) != 0)
? .5
- * bcheck.FastArcTan(
+ * std::atan(
2 * (*bcheck.lCovariance)(1, 0)
/ ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
: 0.;
diff --git a/Core/include/ACTS/Surfaces/TriangleBounds.hpp b/Core/include/ACTS/Surfaces/TriangleBounds.hpp
index 04503f0c9..2d7a571e4 100644
--- a/Core/include/ACTS/Surfaces/TriangleBounds.hpp
+++ b/Core/include/ACTS/Surfaces/TriangleBounds.hpp
@@ -217,9 +217,8 @@ TriangleBounds::inside(const Vector2D& lpos, const BoundaryCheck& bcheck) const
= ((*bcheck.lCovariance)(1, 0) != 0
&& ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)) != 0)
? .5
- * bcheck.FastArcTan(
- 2 * (*bcheck.lCovariance)(1, 0)
- / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
+ * std::atan(2 * (*bcheck.lCovariance)(1, 0)
+ / ((*bcheck.lCovariance)(1, 1) - (*bcheck.lCovariance)(0, 0)))
: 0.;
auto rotMatrix = Eigen::Rotation2D<double>(theta).toRotationMatrix();
ActsMatrixD<2, 2> normal;
diff --git a/Tests/Surfaces/BoundaryCheckTests.cpp b/Tests/Surfaces/BoundaryCheckTests.cpp
index 4c81427fa..bff7129e2 100644
--- a/Tests/Surfaces/BoundaryCheckTests.cpp
+++ b/Tests/Surfaces/BoundaryCheckTests.cpp
@@ -141,20 +141,6 @@ namespace Test {
BOOST_CHECK_SMALL(fastCos - cosValue,
0.001); // claimed max difference in code
}
- /// Unit test for FastArcTan
- BOOST_DATA_TEST_CASE(BoundaryCheckFastArcTanAccuracy,
- bdata::xrange(0., 200., 10.))
- {
- BoundaryCheck b(true);
- // NOTE: Naming violation
- double fastArctan = b.FastArcTan(sample);
- const double atanValue = std::atan(sample);
- // NOTE: Use CHECK_SMALL on the difference to check within absolute
- // tolerance
- // because BOOST_TEST(a==b, tolerance) checks the relative tolerance.
- BOOST_CHECK_SMALL(fastArctan - atanValue,
- 0.0015); // claimed max difference in code
- }
/// Unit test for conversion of smooth ellipse to 4 + 4*n point polygon
BOOST_AUTO_TEST_CASE(BoundaryCheckEllipseToPoly)
--
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