#ifndef TINY_MATRIX_HPP #define TINY_MATRIX_HPP #include <PastisAssert.hpp> #include <Kokkos_Core.hpp> #include <Types.hpp> #include <TinyVector.hpp> #include <iostream> template <size_t N, typename T=double> class TinyMatrix { private: T m_values[N*N]; static_assert((N>0),"TinyMatrix size must be strictly positive"); KOKKOS_INLINE_FUNCTION size_t _index(const size_t& i, const size_t& j) const { return std::move(i*N+j); } void _unpackVariadicInput(const T& t) { m_values[N*N-1] = t; } template <typename... Args> void _unpackVariadicInput(const T& t, Args&&... args) { m_values[N*N-1-sizeof...(args)] = t; this->_unpackVariadicInput(args...); } public: KOKKOS_INLINE_FUNCTION TinyMatrix operator-() const { TinyMatrix opposed; for (size_t i=0; i<N*N; ++i) { opposed.m_values[i] = -m_values[i]; } return std::move(opposed); } KOKKOS_INLINE_FUNCTION friend TinyMatrix operator*(const T& t, const TinyMatrix& A) { TinyMatrix tA; for (size_t i=0; i<N*N; ++i) { tA.m_values[i] = t * A.m_values[i]; } return std::move(tA); } KOKKOS_INLINE_FUNCTION TinyMatrix operator*(const TinyMatrix& B) const { const TinyMatrix& A = *this; TinyMatrix AB; for (size_t i=0; i<N; ++i) { for (size_t j=0; j<N; ++j) { T sum = A(i,0)*B(0,j); for (size_t k=1; k<N; ++k) { sum += A(i,k)*B(k,j); } AB(i,j) = sum; } } return std::move(AB); } KOKKOS_INLINE_FUNCTION TinyVector<N,T> operator*(const TinyVector<N,T>& x) const { const TinyMatrix& A = *this; TinyVector<N,T> Ax; for (size_t i=0; i<N; ++i) { T sum = A(i,0)*x[0]; for (size_t j=1; j<N; ++j) { sum += A(i,j)*x[j]; } Ax[i] = sum; } return std::move(Ax); } KOKKOS_INLINE_FUNCTION friend std::ostream& operator<<(std::ostream& os, const TinyMatrix& A) { if constexpr(N==1) { os << A(0,0); } else { os << '['; for (size_t i=0; i<N; ++i) { os << '(' << A(i,0); for (size_t j=1; j<N; ++j) { os << ',' << A(i,j); } os << ')'; } os << ']'; } return os; } KOKKOS_INLINE_FUNCTION bool operator==(const TinyMatrix& A) const { for (size_t i=0; i<N*N; ++i) { if (m_values[i] != A.m_values[i]) return false; } return true; } KOKKOS_INLINE_FUNCTION bool operator!=(const TinyMatrix& A) const { return not this->operator==(A); } KOKKOS_INLINE_FUNCTION TinyMatrix operator+(const TinyMatrix& A) const { TinyMatrix sum; for (size_t i=0; i<N*N; ++i) { sum.m_values[i] = m_values[i]+A.m_values[i]; } return std::move(sum); } KOKKOS_INLINE_FUNCTION TinyMatrix operator+(TinyMatrix&& A) const { for (size_t i=0; i<N*N; ++i) { A.m_values[i] += m_values[i]; } return std::move(A); } KOKKOS_INLINE_FUNCTION TinyMatrix operator-(const TinyMatrix& A) const { TinyMatrix difference; for (size_t i=0; i<N*N; ++i) { difference.m_values[i] = m_values[i]-A.m_values[i]; } return std::move(difference); } KOKKOS_INLINE_FUNCTION TinyMatrix operator-(TinyMatrix&& A) const { for (size_t i=0; i<N*N; ++i) { A.m_values[i] = m_values[i]-A.m_values[i]; } return std::move(A); } KOKKOS_INLINE_FUNCTION TinyMatrix& operator+=(const TinyMatrix& A) { for (size_t i=0; i<N*N; ++i) { m_values[i] += A.m_values[i]; } return *this; } KOKKOS_INLINE_FUNCTION TinyMatrix& operator-=(const TinyMatrix& A) { for (size_t i=0; i<N*N; ++i) { m_values[i] -= A.m_values[i]; } return *this; } KOKKOS_INLINE_FUNCTION T& operator()(const size_t& i, const size_t& j) { Assert((i<N) and (j<N)); return m_values[_index(i,j)]; } KOKKOS_INLINE_FUNCTION const T& operator()(const size_t& i, const size_t& j) const { Assert((i<N) and (j<N)); return m_values[_index(i,j)]; } KOKKOS_INLINE_FUNCTION TinyMatrix& operator=(const ZeroType& z) { static_assert(std::is_arithmetic<T>(),"Cannot assign 'zero' value for non-arithmetic types"); for (size_t i=0; i<N*N; ++i) { m_values[i] = 0; } return *this; } KOKKOS_INLINE_FUNCTION TinyMatrix& operator=(const IdentityType& I) { static_assert(std::is_arithmetic<T>(),"Cannot assign 'identity' value for non-arithmetic types"); for (size_t i=0; i<N; ++i) { for (size_t j=0; j<N; ++j) { m_values[_index(i,j)] = (i==j) ? 1 : 0; } } return *this; } KOKKOS_INLINE_FUNCTION TinyMatrix& operator=(const TinyMatrix& A) { for (size_t i=0; i<N*N; ++i) { m_values[i] = A.m_values[i]; } return *this; } KOKKOS_INLINE_FUNCTION TinyMatrix& operator=(TinyMatrix&& A) = default; template <typename... Args> KOKKOS_INLINE_FUNCTION TinyMatrix(const T& t, Args&&... args) { static_assert(sizeof...(args)==N*N-1, "wrong number of parameters"); this->_unpackVariadicInput(t, args...); } KOKKOS_INLINE_FUNCTION TinyMatrix()=default; KOKKOS_INLINE_FUNCTION TinyMatrix(const ZeroType& z) { static_assert(std::is_arithmetic<T>(),"Cannot construct from 'zero' value for non-arithmetic types"); for (size_t i=0; i<N*N; ++i) { m_values[i] = 0; } } KOKKOS_INLINE_FUNCTION TinyMatrix(const IdentityType& I) { static_assert(std::is_arithmetic<T>(),"Cannot construct from 'identity' value for non-arithmetic types"); for (size_t i=0; i<N; ++i) { for (size_t j=0; j<N; ++j) { m_values[_index(i,j)] = (i==j) ? 1 : 0; } } } KOKKOS_INLINE_FUNCTION TinyMatrix(const TinyMatrix& A) { for (size_t i=0; i<N*N; ++i) { m_values[i] = A.m_values[i]; } } KOKKOS_INLINE_FUNCTION TinyMatrix(TinyMatrix&& A) = default; KOKKOS_INLINE_FUNCTION ~TinyMatrix()=default; }; template <size_t N, typename T> KOKKOS_INLINE_FUNCTION TinyMatrix<N,T> tensorProduct(const TinyVector<N,T>& x, const TinyVector<N,T>& y) { TinyMatrix<N,T> A; for (size_t i=0; i<N; ++i) { for (size_t j=0; j<N; ++j) { A(i,j) = x[i]*y[j]; } } return std::move(A); } template <size_t N, typename T> KOKKOS_INLINE_FUNCTION T det(const TinyMatrix<N,T>& A) { static_assert(std::is_arithmetic<T>::value, "determinent is not defined for non arithmetic types"); static_assert(std::is_floating_point<T>::value, "determinent for arbitrary dimension N is defined for floating point types only"); TinyMatrix<N,T> M = A; TinyVector<N, size_t> index; for (size_t i=0; i<N; ++i) index[i]=i; T determinent = 1; for (size_t i=0; i<N; ++i) { for (size_t j=i; j<N; ++j) { size_t l = j; const size_t J = index[j]; for (size_t k=j+1; k<N; ++k) { if (std::abs(M(index[k],i)) > std::abs(M(J,i))) { l=k; } } if (l != j) { std::swap(index[l], index[j]); determinent *= -1; } } const size_t I = index[i]; if (M(I,i)==0) return 0; const T inv_Mii = 1./M(I,i); for (size_t k=i+1; k<N; ++k) { const size_t K = index[k]; const T factor = M(K,i)*inv_Mii; for (size_t l=i+1; l<N; ++l) { M(K,l) -= factor*M(I,l); } } } for (size_t i=0; i<N; ++i) { determinent *= M(index[i],i); } return determinent; } template <typename T> KOKKOS_INLINE_FUNCTION T det(const TinyMatrix<1,T>& A) { static_assert(std::is_arithmetic<T>::value, "determinent is not defined for non arithmetic types"); return A(0,0); } template <typename T> KOKKOS_INLINE_FUNCTION T det(const TinyMatrix<2,T>& A) { static_assert(std::is_arithmetic<T>::value, "determinent is not defined for non arithmetic types"); return A(0,0)*A(1,1)-A(1,0)*A(0,1); } template <typename T> KOKKOS_INLINE_FUNCTION T det(const TinyMatrix<3,T>& A) { static_assert(std::is_arithmetic<T>::value, "determinent is not defined for non arithmetic types"); return A(0,0)*(A(1,1)*A(2,2)-A(2,1)*A(1,2)) -A(1,0)*(A(0,1)*A(2,2)-A(2,1)*A(0,2)) +A(2,0)*(A(0,1)*A(1,2)-A(1,1)*A(0,2)); } #endif // TINYMATRIX_HPP