From 251ecc0ab9ee7bf923c5212ab93bdf02dc8156d7 Mon Sep 17 00:00:00 2001
From: Benoit Jacob <jacob.benoit.1@gmail.com>
Date: Sun, 24 Aug 2008 17:31:03 +0000
Subject: [PATCH] Rename someOrthogonal to unitOrthogonal. Fix a bug in it,
 with dyn-size vectors of size <=3. Update doc and test to reflect that it
 always returns a unit vector.

---
 Eigen/src/Core/MatrixBase.h       |  2 +-
 Eigen/src/Geometry/OrthoMethods.h | 24 ++++++++++++++----------
 test/geometry.cpp                 |  9 ++++++---
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/Eigen/src/Core/MatrixBase.h b/Eigen/src/Core/MatrixBase.h
index c563466b4..dbb481914 100644
--- a/Eigen/src/Core/MatrixBase.h
+++ b/Eigen/src/Core/MatrixBase.h
@@ -567,7 +567,7 @@ template<typename Derived> class MatrixBase
 
     template<typename OtherDerived>
     EvalType cross(const MatrixBase<OtherDerived>& other) const;
-    EvalType someOrthogonal(void) const;
+    EvalType unitOrthogonal(void) const;
     
     #ifdef EIGEN_MATRIXBASE_PLUGIN
     #include EIGEN_MATRIXBASE_PLUGIN
diff --git a/Eigen/src/Geometry/OrthoMethods.h b/Eigen/src/Geometry/OrthoMethods.h
index 046ca0c88..9ca107541 100644
--- a/Eigen/src/Geometry/OrthoMethods.h
+++ b/Eigen/src/Geometry/OrthoMethods.h
@@ -47,7 +47,7 @@ MatrixBase<Derived>::cross(const MatrixBase<OtherDerived>& other) const
 }
 
 template<typename Derived, int Size = Derived::SizeAtCompileTime>
-struct ei_someOrthogonal_selector
+struct ei_unitOrthogonal_selector
 {
   typedef typename ei_eval<Derived>::type VectorType;
   typedef typename ei_traits<Derived>::Scalar Scalar;
@@ -66,7 +66,9 @@ struct ei_someOrthogonal_selector
     || (!ei_isMuchSmallerThan(src.y(), src.z())))
     {
       RealScalar invnm = Scalar(1)/src.template start<2>().norm();
-      perp.template start<3>() << -ei_conj(src.y())*invnm, ei_conj(src.x())*invnm, 0;
+      perp.coeffRef(0) = -ei_conj(src.y())*invnm;
+      perp.coeffRef(1) = ei_conj(src.x())*invnm;
+      perp.coeffRef(2) = 0;
     }
     /* if both x and y are close to zero, then the vector is close
      * to the z-axis, so it's far from colinear to the x-axis for instance.
@@ -75,10 +77,12 @@ struct ei_someOrthogonal_selector
     else
     {
       RealScalar invnm = Scalar(1)/src.template end<2>().norm();
-      perp.template start<3>() << 0, -ei_conj(src.z())*invnm, ei_conj(src.y())*invnm;
+      perp.coeffRef(0) = 0;
+      perp.coeffRef(1) = -ei_conj(src.z())*invnm;
+      perp.coeffRef(2) = ei_conj(src.y())*invnm;
     }
-    if (Derived::SizeAtCompileTime>3
-    || (Derived::SizeAtCompileTime==Dynamic && src.size()>3))
+    if( (Derived::SizeAtCompileTime!=Dynamic && Derived::SizeAtCompileTime>3)
+     || (Derived::SizeAtCompileTime==Dynamic && src.size()>3) )
       perp.end(src.size()-3).setZero();
 
     return perp;
@@ -86,26 +90,26 @@ struct ei_someOrthogonal_selector
 };
 
 template<typename Derived>
-struct ei_someOrthogonal_selector<Derived,2>
+struct ei_unitOrthogonal_selector<Derived,2>
 {
   typedef typename ei_eval<Derived>::type VectorType;
   inline static VectorType run(const Derived& src)
   { return VectorType(-ei_conj(src.y()), ei_conj(src.x())).normalized(); }
 };
 
-/** \returns an orthogonal vector of \c *this
+/** \returns a unit vector which is orthogonal to \c *this
   *
   * The size of \c *this must be at least 2. If the size is exactly 2,
-  * then the returned vector is a counter clock wise rotation of \c *this, i.e., (-y,x).
+  * then the returned vector is a counter clock wise rotation of \c *this, i.e., (-y,x).normalized().
   *
   * \sa cross()
   */
 template<typename Derived>
 typename MatrixBase<Derived>::EvalType
-MatrixBase<Derived>::someOrthogonal() const
+MatrixBase<Derived>::unitOrthogonal() const
 {
   EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived);
-  return ei_someOrthogonal_selector<Derived>::run(derived());
+  return ei_unitOrthogonal_selector<Derived>::run(derived());
 }
 
 #endif // EIGEN_ORTHOMETHODS_H
diff --git a/test/geometry.cpp b/test/geometry.cpp
index 82f0a2797..a3876c8d8 100644
--- a/test/geometry.cpp
+++ b/test/geometry.cpp
@@ -58,9 +58,12 @@ template<typename Scalar> void geometry(void)
       (v0.cross(v1).cross(v0)).normalized();
   VERIFY(m.isUnitary());
 
-  // someOrthogonal
-  VERIFY_IS_MUCH_SMALLER_THAN(u0.someOrthogonal().dot(u0), Scalar(1));
-  VERIFY_IS_MUCH_SMALLER_THAN(v0.someOrthogonal().dot(v0), Scalar(1));
+  // unitOrthogonal
+  VERIFY_IS_MUCH_SMALLER_THAN(u0.unitOrthogonal().dot(u0), Scalar(1));
+  VERIFY_IS_MUCH_SMALLER_THAN(v0.unitOrthogonal().dot(v0), Scalar(1));
+  VERIFY_IS_APPROX(u0.unitOrthogonal().norm(), Scalar(1));
+  VERIFY_IS_APPROX(v0.unitOrthogonal().norm(), Scalar(1));
+
 
   q1 = AngleAxis(ei_random<Scalar>(-M_PI, M_PI), v0.normalized());
   q2 = AngleAxis(ei_random<Scalar>(-M_PI, M_PI), v1.normalized());