MinimizerVariableArrayTraits.hpp

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/* 
 * MinimizerVariableArrayTraits.hpp 
 *
 * Copyright (C) 2003 Thomas Seidel <thomas.seidel@univie.ac.at>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; see the file COPYING. If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
 
#ifndef CDPL_MATH_MINIMIZERVARIABLEARRAYTRAITS_HPP
#define CDPL_MATH_MINIMIZERVARIABLEARRAYTRAITS_HPP
 
#include <vector>
 
#include "CDPL/Math/VectorArray.hpp"
#include "CDPL/Math/TypeTraits.hpp"
 
 
namespace CDPL
{
 
    namespace Math
    {
 
        template <typename A>
        struct MinimizerVariableArrayTraits
        {
 
            typedef A                     ArrayType;
            typedef typename A::ValueType ValueType;
            typedef typename A::SizeType  SizeType;
 
            template <typename T>
            static T dot(const ArrayType& a1, const ArrayType& a2)
            {
                return innerProd(a1, a2);
            }
 
            template <typename T>
            static T norm2(const ArrayType& a)
            {
                T        scale = T();
                T        ssq   = T(1);
                SizeType size  = a.getSize();
 
                if (size == SizeType(0))
                    return T();
 
                else if (size == SizeType(1))
                    return TypeTraits<ValueType>::abs(a(0));
 
                for (SizeType i = 0; i < size; i++) {
                    const ValueType& x = a(i);
 
                    if (x != ValueType()) {
                        const typename TypeTraits<ValueType>::RealType ax = TypeTraits<ValueType>::abs(x);
 
                        if (scale < ax) {
                            ssq   = 1 + ssq * (scale / ax) * (scale / ax);
                            scale = ax;
 
                        } else {
                            ssq += (ax / scale) * (ax / scale);
                        }
                    }
                }
 
                return (scale * TypeTraits<T>::sqrt(ssq));
            }
 
            template <typename T>
            static void axpy(const T& alpha, const ArrayType& x, ArrayType& y)
            {
                y.plusAssign(alpha * x);
            }
 
            static void clear(ArrayType& a)
            {
                a.clear(ValueType());
            }
 
            static void assign(ArrayType& a1, const ArrayType& a2)
            {
                a1.assign(a2);
            }
 
            template <typename T>
            static void multiply(ArrayType& a, const T& v)
            {
                a *= v;
            }
 
            static void sub(ArrayType& a1, const ArrayType& a2)
            {
                a1.minusAssign(a2);
            }
        };
 
        template <typename V>
        struct MinimizerVariableArrayTraits<VectorArray<V> >
        {
 
            typedef VectorArray<V>               ArrayType;
            typedef V                            VectorType;
            typedef typename V::ValueType        ValueType;
            typedef typename ArrayType::SizeType SizeType;
 
            template <typename T>
            static T dot(const ArrayType& a1, const ArrayType& a2)
            {
                T result = T();
 
                for (typename ArrayType::ConstElementIterator it1 = a1.getElementsBegin(), it2 = a2.getElementsBegin(), end1 = a1.getElementsEnd(); it1 != end1; ++it1, ++it2)
                    result += innerProd(*it1, *it2);
 
                return result;
            }
 
            template <typename T>
            static T norm2(const ArrayType& a)
            {
                T scale = T();
                T ssq   = T(1);
 
                for (typename ArrayType::ConstElementIterator it = a.getElementsBegin(), end = a.getElementsEnd(); it != end; ++it) {
                    const typename VectorType::ConstPointer vx  = it->getData();
                    typename VectorType::SizeType           dim = it->getSize();
 
                    for (typename VectorType::SizeType i = 0; i < dim; i++) {
                        const ValueType& x = vx[i];
 
                        if (x != ValueType()) {
                            const typename TypeTraits<ValueType>::RealType ax = TypeTraits<ValueType>::abs(x);
 
                            if (scale < ax) {
                                ssq   = 1 + ssq * (scale / ax) * (scale / ax);
                                scale = ax;
 
                            } else {
                                ssq += (ax / scale) * (ax / scale);
                            }
                        }
                    }
                }
 
                return (scale * TypeTraits<T>::sqrt(ssq));
            }
 
            template <typename T>
            static void axpy(const T& alpha, const ArrayType& x, ArrayType& y)
            {
                typename ArrayType::ElementIterator it2 = y.getElementsBegin();
                VectorType                          tmp;
 
                for (typename ArrayType::ConstElementIterator it1 = x.getElementsBegin(), end1 = x.getElementsEnd(); it1 != end1; ++it1, ++it2) {
                    tmp.assign(*it1);
                    tmp *= alpha;
 
                    it2->plusAssign(tmp);
                }
            }
 
            static void clear(ArrayType& a)
            {
                for (typename ArrayType::ElementIterator it = a.getElementsBegin(), end = a.getElementsEnd(); it != end; ++it)
                    it->clear(ValueType());
            }
 
            static void assign(ArrayType& a1, const ArrayType& a2)
            {
                a1 = a2;
            }
 
            template <typename T>
            static void multiply(ArrayType& a, const T& v)
            {
                for (typename ArrayType::ElementIterator it = a.getElementsBegin(), end = a.getElementsEnd(); it != end; ++it)
                    *it *= v;
            }
 
            static void sub(ArrayType& a1, const ArrayType& a2)
            {
                typename ArrayType::ConstElementIterator it2 = a2.getElementsBegin();
 
                for (typename ArrayType::ElementIterator it1 = a1.getElementsBegin(), end1 = a1.getElementsEnd(); it1 != end1; ++it1, ++it2)
                    it1->minusAssign(*it2);
            }
        };
 
        template <typename V>
        struct MinimizerVariableArrayTraits<std::vector<V> >
        {
 
            typedef std::vector<V>                ArrayType;
            typedef V                             VectorType;
            typedef typename V::ValueType         ValueType;
            typedef typename ArrayType::size_type SizeType;
 
            template <typename T>
            static T dot(const ArrayType& a1, const ArrayType& a2)
            {
                T result = T();
 
                for (typename ArrayType::const_iterator it1 = a1.begin(), it2 = a2.begin(), end1 = a1.end(); it1 != end1; ++it1, ++it2)
                    result += innerProd(*it1, *it2);
 
                return result;
            }
 
            template <typename T>
            static T norm2(const ArrayType& a)
            {
                T scale = T();
                T ssq   = T(1);
 
                for (typename ArrayType::const_iterator it = a.begin(), end = a.end(); it != end; ++it) {
                    const typename VectorType::ConstPointer vx  = it->getData();
                    typename VectorType::SizeType           dim = it->getSize();
 
                    for (typename VectorType::SizeType i = 0; i < dim; i++) {
                        const ValueType& x = vx[i];
 
                        if (x != ValueType()) {
                            const typename TypeTraits<ValueType>::RealType ax = TypeTraits<ValueType>::abs(x);
 
                            if (scale < ax) {
                                ssq   = 1 + ssq * (scale / ax) * (scale / ax);
                                scale = ax;
 
                            } else {
                                ssq += (ax / scale) * (ax / scale);
                            }
                        }
                    }
                }
 
                return (scale * TypeTraits<T>::sqrt(ssq));
            }
 
            template <typename T>
            static void axpy(const T& alpha, const ArrayType& x, ArrayType& y)
            {
                typename ArrayType::iterator it2 = y.begin();
                VectorType                   tmp;
 
                for (typename ArrayType::const_iterator it1 = x.begin(), end1 = x.end(); it1 != end1; ++it1, ++it2) {
                    tmp.assign(*it1);
                    tmp *= alpha;
 
                    it2->plusAssign(tmp);
                }
            }
 
            static void clear(ArrayType& a)
            {
                for (typename ArrayType::iterator it = a.begin(), end = a.end(); it != end; ++it)
                    it->clear(ValueType());
            }
 
            static void assign(ArrayType& a1, const ArrayType& a2)
            {
                a1 = a2;
            }
 
            template <typename T>
            static void multiply(ArrayType& a, const T& v)
            {
                for (typename ArrayType::iterator it = a.begin(), end = a.end(); it != end; ++it)
                    *it *= v;
            }
 
            static void sub(ArrayType& a1, const ArrayType& a2)
            {
                typename ArrayType::const_iterator it2 = a2.begin();
 
                for (typename ArrayType::iterator it1 = a1.begin(), end1 = a1.end(); it1 != end1; ++it1, ++it2)
                    it1->minusAssign(*it2);
            }
        };
        
    } // namespace Math
} // namespace CDPL
 
#endif // CDPL_MATH_MINIMIZERVARIABLEARRAYTRAITS_HPP