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authorGravatar Benoit Jacob <jacob.benoit.1@gmail.com>2007-12-28 16:00:55 +0000
committerGravatar Benoit Jacob <jacob.benoit.1@gmail.com>2007-12-28 16:00:55 +0000
commitdfdad129a3c6d5437eb001f5fe6d37de3fc07238 (patch)
treeafbde1562e62b3952c8ce7a6b9c3cdd95fdb69c0 /Eigen/src/Core/Dot.h
parente7bdbe2e6a7d3d3e3f498e1ba9159b0ec1a8ccae (diff)
move Core/ to a src/ subdir, in preparation for following changes
Diffstat (limited to 'Eigen/src/Core/Dot.h')
-rw-r--r--Eigen/src/Core/Dot.h126
1 files changed, 126 insertions, 0 deletions
diff --git a/Eigen/src/Core/Dot.h b/Eigen/src/Core/Dot.h
new file mode 100644
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+++ b/Eigen/src/Core/Dot.h
@@ -0,0 +1,126 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2006-2007 Benoit Jacob <jacob@math.jussieu.fr>
+//
+// Eigen is free software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the Free Software
+// Foundation; either version 2 or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+// details.
+//
+// You should have received a copy of the GNU General Public License along
+// with Eigen; if not, write to the Free Software Foundation, Inc., 51
+// Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+//
+// As a special exception, if other files instantiate templates or use macros
+// or functions from this file, or you compile this file and link it
+// with other works to produce a work based on this file, this file does not
+// by itself cause the resulting work to be covered by the GNU General Public
+// License. This exception does not invalidate any other reasons why a work
+// based on this file might be covered by the GNU General Public License.
+
+#ifndef EIGEN_DOT_H
+#define EIGEN_DOT_H
+
+template<int Index, int Size, typename Derived1, typename Derived2>
+struct DotUnroller
+{
+ static void run(const Derived1 &v1, const Derived2& v2, typename Derived1::Scalar &dot)
+ {
+ DotUnroller<Index-1, Size, Derived1, Derived2>::run(v1, v2, dot);
+ dot += v1.coeff(Index) * conj(v2.coeff(Index));
+ }
+};
+
+template<int Size, typename Derived1, typename Derived2>
+struct DotUnroller<0, Size, Derived1, Derived2>
+{
+ static void run(const Derived1 &v1, const Derived2& v2, typename Derived1::Scalar &dot)
+ {
+ dot = v1.coeff(0) * conj(v2.coeff(0));
+ }
+};
+
+template<int Index, typename Derived1, typename Derived2>
+struct DotUnroller<Index, Dynamic, Derived1, Derived2>
+{
+ static void run(const Derived1&, const Derived2&, typename Derived1::Scalar&) {}
+};
+
+// prevent buggy user code from causing an infinite recursion
+template<int Index, typename Derived1, typename Derived2>
+struct DotUnroller<Index, 0, Derived1, Derived2>
+{
+ static void run(const Derived1&, const Derived2&, typename Derived1::Scalar&) {}
+};
+
+/** \returns the dot product of *this with other.
+ *
+ * \only_for_vectors
+ *
+ * \note If the scalar type is complex numbers, then this function returns the hermitian
+ * (sesquilinear) dot product, linear in the first variable and anti-linear in the
+ * second variable.
+ *
+ * \sa norm2(), norm()
+ */
+template<typename Scalar, typename Derived>
+template<typename OtherDerived>
+Scalar MatrixBase<Scalar, Derived>::dot(const OtherDerived& other) const
+{
+ assert(IsVectorAtCompileTime && OtherDerived::IsVectorAtCompileTime && size() == other.size());
+ Scalar res;
+ if(EIGEN_UNROLLED_LOOPS && SizeAtCompileTime != Dynamic && SizeAtCompileTime <= 16)
+ DotUnroller<SizeAtCompileTime-1, SizeAtCompileTime, Derived, OtherDerived>
+ ::run(*static_cast<const Derived*>(this), other, res);
+ else
+ {
+ res = (*this).coeff(0) * conj(other.coeff(0));
+ for(int i = 1; i < size(); i++)
+ res += (*this).coeff(i)* conj(other.coeff(i));
+ }
+ return res;
+}
+
+/** \returns the squared norm of *this, i.e. the dot product of *this with itself.
+ *
+ * \only_for_vectors
+ *
+ * \sa dot(), norm()
+ */
+template<typename Scalar, typename Derived>
+typename NumTraits<Scalar>::Real MatrixBase<Scalar, Derived>::norm2() const
+{
+ return real(dot(*this));
+}
+
+/** \returns the norm of *this, i.e. the square root of the dot product of *this with itself.
+ *
+ * \only_for_vectors
+ *
+ * \sa dot(), norm2()
+ */
+template<typename Scalar, typename Derived>
+typename NumTraits<Scalar>::Real MatrixBase<Scalar, Derived>::norm() const
+{
+ return sqrt(norm2());
+}
+
+/** \returns an expression of the quotient of *this by its own norm.
+ *
+ * \only_for_vectors
+ *
+ * \sa norm()
+ */
+template<typename Scalar, typename Derived>
+const ScalarMultiple<typename NumTraits<Scalar>::Real, Derived>
+MatrixBase<Scalar, Derived>::normalized() const
+{
+ return (*this) / norm();
+}
+
+#endif // EIGEN_DOT_H