[MaL] Remove unused Constant and LinearFunction.

MathLib/ConstantFunction.h

-/**
- * \author Norihiro Watanabe
- * \date   2013-08-13
- *
- * \copyright
- * Copyright (c) 2012-2019, OpenGeoSys Community (http://www.opengeosys.org)
- *            Distributed under a Modified BSD License.
- *              See accompanying file LICENSE.txt or
- *              http://www.opengeosys.org/project/license
- *
- */
-
-#pragma once
-
-#include <array>
-#include <numeric>
-
-namespace MathLib
-{
-
-/**
- * A constant function.
- * \f[
- *     f(x_1,...,x_k)=a_0
- * \f]
- */
-template <typename T_TYPE>
-class ConstantFunction
-{
-public:
-    explicit ConstantFunction(T_TYPE const& value)
-    : _value(value)
-    {}
-
-    T_TYPE operator()() const
-    {
-        return _value;
-    }
-private:
-    T_TYPE const _value;
-};
-
-}

MathLib/LinearFunction.h

-/**
- * \author Norihiro Watanabe
- * \date   2013-08-13
- *
- * \copyright
- * Copyright (c) 2012-2019, OpenGeoSys Community (http://www.opengeosys.org)
- *            Distributed under a Modified BSD License.
- *              See accompanying file LICENSE.txt or
- *              http://www.opengeosys.org/project/license
- *
- */
-
-#pragma once
-
-#include <array>
-#include <numeric>
-#include <utility>
-
-namespace MathLib
-{
-
-/**
- * Linear function
- * \f[
- *     f(x_1,...,x_k)=a_0+a_1*x_1+...+a_k*x_k
- * \f]
- *
- * \tparam T_TYPE  value type
- * \tparam N_VARS  the number of variables (k)
- */
-template <typename T_TYPE, unsigned N_VARS>
-class LinearFunction
-{
-public:
-    /**
-     * Constructor
-     * \param coefficients  an array of coefficients of a linear function.
-     * The size of the coefficient array should equal to the number of variables + 1
-     */
-    explicit LinearFunction(std::array<T_TYPE, N_VARS + 1> coefficients)
-        : _coefficients(std::move(coefficients))
-    {}
-
-    /**
-     * evaluate the function
-     * \param x  an array of variables. the size of the array should equal to the number of variables
-     */
-    T_TYPE operator()(T_TYPE const * const x) const
-    {
-        return std::inner_product(_coefficients.cbegin()+1, _coefficients.cend(), x, _coefficients.front());
-    }
-
-private:
-    /// Coefficients of a linear function
-    const std::array<T_TYPE, N_VARS+1> _coefficients;
-};
-
-}  // namespace MathLib