SmallMatrix.h

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// This file is part of the MercuryDPM project (https://www.mercurydpm.org).
// Copyright (c), The MercuryDPM Developers Team. All rights reserved.
// License: BSD 3-Clause License; see the LICENSE file in the root directory.
 
/*
 This file forms part of hpGEM. This package has been developed over a number of years by various people at the University of Twente and a full list of contributors can be found at
 http://hpgem.org/about-the-code/team
 
 This code is distributed using BSD 3-Clause License. A copy of which can found below.
 
 
 Copyright (c) 2014, University of Twente
 All rights reserved.
 
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//Note: This code is copied and adapted from hpGEM (see license above), version 22th of January 2016. It has been
//integrated into MercuryDPM at 16th of March 2017.
 
#ifndef MERCURYDPM_SMALLMATRIX_H
#define MERCURYDPM_SMALLMATRIX_H
 
#include "GeneralDefine.h"
#include "Logger.h"
#include "SmallVector.h"
 
template<unsigned int numberOfRows, unsigned int numberOfColumns>
class SmallMatrix
{
public:
    
    SmallMatrix()
            : data_()
    {
    }
    
    SmallMatrix(const SmallVector<numberOfRows>& other)
            : data_()
    {
        logger.assert_debug(numberOfColumns == 1, "Trying to construct a matrix with more than 1 columns from a vector");
        std::copy(other.data(), other.data() + numberOfRows, data_.begin());
    }
    
    SmallMatrix(const Mdouble& c)
            : data_()
    {
        data_.fill(c);
    }
    
    SmallMatrix(const std::initializer_list<SmallVector<numberOfRows>>& entries)
            : data_()
    {
        logger.assert_debug(entries.size() == numberOfColumns, "expected a matrix with % "
                                                         "columns, but got a matrix with % columns", numberOfColumns,
                      entries.size());
        unsigned int column = 0;
        for (const SmallVector<numberOfRows>& entry : entries)
        {
            for (unsigned int i = 0; i < numberOfRows; ++i)
            {
                (*this)(i, column) = entry[i];
            }
            ++column;
        }
    }
    
    SmallMatrix(const SmallMatrix& other)
            : data_()
    {
        std::copy(other.data_.begin(), other.data_.end(), data_.begin());
    }
    
    SmallMatrix(std::array<SmallVector<numberOfRows>, numberOfColumns> entries)
            : data_()
    {
        for (unsigned int i = 0; i < numberOfRows; ++i)
        {
            for (unsigned int j = 0; j < numberOfColumns; ++j)
            {
                (*this)(i, j) = entries[j][i];
            }
        }
    }
    
    SmallMatrix(SmallMatrix&& other)
            : data_(std::move(other.data_))
    {
    }
    
    Mdouble& operator()(unsigned int n, unsigned int m)
    {
        logger.assert_debug(n < numberOfRows, "Requested row number % for a matrix with only % rows", n, numberOfRows);
        logger.assert_debug(m < numberOfColumns, "Requested column number % for a matrix with only % columns", m,
                      numberOfColumns);
        return data_[n + m * numberOfRows];
    }
    
    const Mdouble& operator()(unsigned int n, unsigned int m) const
    {
        logger.assert_debug(n < numberOfRows, "Requested row number % for a matrix with only % rows", n, numberOfRows);
        logger.assert_debug(m < numberOfColumns, "Requested column number % for a matrix with only % columns", m,
                      numberOfColumns);
        return data_[n + m * numberOfRows];
    }
    
    Mdouble& operator[](const unsigned int n)
    {
        logger.assert_debug(n < numberOfRows * numberOfColumns, "Requested entry % for a matrix with only % entries", n,
                      numberOfRows * numberOfColumns);
        return data_[n];
    }
    
    const Mdouble& operator[](const unsigned int n) const
    {
        logger.assert_debug(n < numberOfRows * numberOfColumns, "Requested entry % for a matrix with only % entries", n,
                      numberOfRows * numberOfColumns);
        return data_[n];
    }
    
    SmallVector<numberOfRows> operator*(SmallVector<numberOfColumns>& right);
    
    SmallVector<numberOfRows> operator*(SmallVector<numberOfColumns>& right) const;
    
    SmallMatrix operator*(const Mdouble& right) const
    {
        SmallMatrix result;
        std::transform(data_.begin(), data_.end(), result.data_.begin(),
                       std::bind(std::multiplies<Mdouble>(), std::placeholders::_1, right));
        return result;
    }
    
    template<unsigned int K>
    SmallMatrix<numberOfRows, K> operator*(const SmallMatrix<numberOfColumns, K>& other);
    
    template<unsigned int K>
    SmallMatrix<numberOfRows, K> operator*(const SmallMatrix<numberOfColumns, K>& other) const;
    
    SmallMatrix& operator+=(const SmallMatrix& other)
    {
        std::transform(data_.begin(), data_.end(), other.data_.begin(), data_.begin(), std::plus<Mdouble>());
        return *this;
    }
    
    SmallMatrix& operator-=(const SmallMatrix& other)
    {
        std::transform(data_.begin(), data_.end(), other.data_.begin(), data_.begin(), std::minus<Mdouble>());
        return *this;
    }
    
    SmallMatrix operator+(const SmallMatrix& other) const
    {
        SmallMatrix result;
        std::transform(data_.begin(), data_.end(), other.data_.begin(), result.data_.begin(), std::plus<Mdouble>());
        return result;
    }
    
    SmallMatrix operator-(const SmallMatrix& other) const
    {
        SmallMatrix result;
        std::transform(data_.begin(), data_.end(), other.data_.begin(), result.data_.begin(), std::minus<Mdouble>());
        return result;
    }
    
    SmallMatrix operator-() const
    {
        return *this * -1.;
    }
    
    SmallMatrix& operator*=(const Mdouble& scalar)
    {
        std::transform(data_.begin(), data_.end(), data_.begin(),
                       std::bind(std::multiplies<Mdouble>(), std::placeholders::_1, scalar));
        return *this;
    }
    
    SmallMatrix& operator*=(const SmallMatrix<numberOfColumns, numberOfColumns>& other);
    
    SmallMatrix& operator/=(const Mdouble& scalar)
    {
        std::transform(data_.begin(), data_.end(), data_.begin(),
                       std::bind(std::divides<Mdouble>(), std::placeholders::_1, scalar));
        return *this;
    }
    
    SmallMatrix operator/(const Mdouble& scalar) const
    {
        SmallMatrix result;
        std::transform(data_.begin(), data_.end(), result.data_.begin(),
                       std::bind(std::divides<Mdouble>(), std::placeholders::_1, scalar));
        return result;
    }
    
    SmallMatrix& operator=(const SmallMatrix& right)
    {
        std::copy(right.data_.begin(), right.data_.end(), data_.begin());
        return *this;
    }
    
    SmallMatrix& operator=(SmallMatrix&& right)
    {
        std::move(right.data_.begin(), right.data_.end(), data_.begin());
        return *this;
    }
    
    SmallVector<numberOfRows> computeWedgeStuffVector() const;
    
    void axpy(Mdouble a, const SmallMatrix& x)
    {
        for (unsigned int i = 0; i < numberOfRows * numberOfColumns; ++i)
        {
            data_[i] += a * x[i];
        }
    }
    
    unsigned int size() const
    {
        return numberOfRows * numberOfColumns;
    }
    
    unsigned int getNumberOfRows() const
    {
        return numberOfRows;
    }
    
    unsigned int getNRows() const
    {
        return getNumberOfRows();
    }
    
    unsigned int getNumberOfColumns() const
    {
        return numberOfColumns;
    }
    
    unsigned int getNCols() const
    {
        return getNumberOfColumns();
    }
    
    SmallVector<numberOfRows> getColumn(unsigned int j) const
    {
        logger.assert_debug(j < numberOfColumns, "Asked for column %, but there are only % columns", j, numberOfColumns);
        return SmallVector<numberOfRows>(data() + j * numberOfRows);
    }
    
    SmallVector<numberOfColumns> getRow(unsigned int i) const
    {
        logger.assert_debug(i < numberOfRows, "Asked for row %, but there are only % rows", i, numberOfRows);
        SmallVector<numberOfColumns> result;
        for (unsigned int j = 0; j < numberOfColumns; ++j)
        {
            result[j] = (*this)(i, j);
        }
        return result;
    }
    
    SmallMatrix LUfactorisation() const;
    
    Mdouble determinant() const;
    
    SmallMatrix inverse() const;
    
    SmallMatrix<numberOfColumns, numberOfRows> transpose() const
    {
        SmallMatrix<numberOfColumns, numberOfRows> result;
        for (unsigned int i = 0; i < numberOfRows; ++i)
        {
            for (unsigned int j = 0; j < numberOfColumns; ++j)
            {
                result(j, i) = (*this)(i, j);
            }
        }
        return result;
    }
    
    template<unsigned int numberOfRightHandSideColumns>
    void solve(SmallMatrix<numberOfRows, numberOfRightHandSideColumns>& B) const;
    
    void solve(SmallVector<numberOfRows>& b) const;
    
    Mdouble* data()
    {
        return data_.data();
    }
    
    const Mdouble* data() const
    {
        return data_.data();
    }
 
private:
    std::array<Mdouble, numberOfRows * numberOfColumns> data_;
};
 
template<unsigned int numberOfRows, unsigned int numberOfColumns>
std::ostream& operator<<(std::ostream& os, const SmallMatrix<numberOfRows, numberOfColumns>& A)
{
    for (unsigned int i = 0; i < numberOfRows; ++i)
    {
        os << A.getRow(i) << std::endl;
    }
    return os;
}
 
template<unsigned int numberOfRows, unsigned int numberOfColumns>
SmallMatrix<numberOfRows, numberOfColumns>
operator*(const Mdouble d, const SmallMatrix<numberOfRows, numberOfColumns>& mat)
{
    return mat * d;
}
 
template<unsigned int numberOfRows, unsigned int numberOfColumns>
SmallVector<numberOfColumns> operator*(SmallVector<numberOfRows>& vec, SmallMatrix<numberOfRows, numberOfColumns>& mat);
 
#include "SmallMatrix_impl.h"
 
 
#endif //MERCURYDPM_SMALLMATRIX_H