#ifndef MSP_LINAL_MATRIX_H_
#define MSP_LINAL_MATRIX_H_
+#include <algorithm>
+#include <ostream>
#include "vector.h"
namespace Msp {
namespace LinAl {
/**
-A general mathematical matrix.
+A general mathematical matrix with M rows and N columns.
*/
template<typename T, unsigned M, unsigned N>
class Matrix
{
+public:
+ typedef T ElementType;
+
private:
T data[M*N];
Matrix(const T *);
template<typename U>
Matrix(const Matrix<U, M, N> &);
+
static Matrix from_columns(const Vector<T, M> *);
static Matrix from_rows(const Vector<T, N> *);
- T &operator()(unsigned, unsigned);
- const T &operator()(unsigned, unsigned) const;
+ unsigned rows() const { return M; }
+ unsigned columns() const { return N; }
+
+ T &element(unsigned i, unsigned j) { return data[i+M*j]; }
+ const T &element(unsigned i, unsigned j) const { return data[i+M*j]; }
+ T &operator()(unsigned i, unsigned j) { return element(i, j); }
+ const T &operator()(unsigned i, unsigned j) const { return element(i, j); }
+
+ Vector<T, M> column(unsigned i) const { return Vector<T, M>(data+M*i); }
+ Vector<T, N> row(unsigned i) const { return Vector<T, N>(data+i, M); }
+
+ template<unsigned P, unsigned Q>
+ Matrix<T, P, Q> select(const Vector<unsigned, P> &, const Vector<unsigned, Q> &) const;
+
+ template<unsigned P, unsigned Q>
+ Matrix<T, P, Q> block(unsigned, unsigned) const;
Matrix &operator*=(T);
Matrix &operator/=(T);
Matrix &operator+=(const Matrix &);
Matrix &operator-=(const Matrix &);
- Matrix<T, N, M> transpose() const;
+ Matrix &exchange_rows(unsigned, unsigned);
+ Matrix &multiply_row(unsigned, T);
+ Matrix &add_row(unsigned, unsigned, T);
};
template<typename T, unsigned M, unsigned N>
-inline T &Matrix<T, M, N>::operator()(unsigned i, unsigned j)
+inline Matrix<T, M, N>::Matrix()
+{
+ std::fill(data, data+M*N, T());
+}
+
+template<typename T, unsigned M, unsigned N>
+inline Matrix<T, M, N>::Matrix(const T *d)
+{
+ std::copy(d, d+M*N, data);
+}
+
+template<typename T, unsigned M, unsigned N>
+template<typename U>
+inline Matrix<T, M, N>::Matrix(const Matrix<U, M, N> &other)
{
- return data[i+M*j];
+ for(unsigned i=0; i<M; ++i)
+ for(unsigned j=0; j<N; ++j)
+ element(i, j) = other(i, j);
}
template<typename T, unsigned M, unsigned N>
-inline const T &Matrix<T, M, N>::operator()(unsigned i, unsigned j) const
+inline Matrix<T, M, N> Matrix<T, M, N>::from_columns(const Vector<T, M> *v)
{
- return data[i+M*j];
+ Matrix<T, M, N> m;
+ for(unsigned i=0; i<M; ++i)
+ for(unsigned j=0; j<N; ++j)
+ m(i, j) = v[j][i];
+ return m;
+}
+
+template<typename T, unsigned M, unsigned N>
+inline Matrix<T, M, N> Matrix<T, M, N>::from_rows(const Vector<T, N> *v)
+{
+ Matrix<T, M, N> m;
+ for(unsigned i=0; i<M; ++i)
+ for(unsigned j=0; j<N; ++j)
+ m(i, j) = v[i][j];
+ return m;
+}
+
+template<typename T, unsigned M, unsigned N>
+template<unsigned P, unsigned Q>
+inline Matrix<T, P, Q> Matrix<T, M, N>::select(const Vector<unsigned, P> &row_indices, const Vector<unsigned, Q> &col_indices) const
+{
+ Matrix<T, P, Q> r;
+ for(unsigned j=0; j<P; ++j)
+ for(unsigned i=0; i<Q; ++i)
+ r(j, i) = element(row_indices[j], col_indices[i]);
+ return r;
+}
+
+template<typename T, unsigned M, unsigned N>
+template<unsigned P, unsigned Q>
+inline Matrix<T, P, Q> Matrix<T, M, N>::block(unsigned y, unsigned x) const
+{
+ Matrix<T, P, Q> r;
+ for(unsigned j=0; j<P; ++j)
+ for(unsigned i=0; i<Q; ++i)
+ r(j, i) = element(y+j, x+i);
+ return r;
}
template<typename T, unsigned M, unsigned N>
return m*s;
}
+template<typename T, unsigned M, unsigned P, unsigned N>
+inline Matrix<T, M, N> operator*(const Matrix<T, M, P> &m1, const Matrix<T, P, N> &m2)
+{
+ Matrix<T, M, N> r;
+ for(unsigned i=0; i<M; ++i)
+ for(unsigned j=0; j<N; ++j)
+ for(unsigned k=0; k<P; ++k)
+ r(i, j) += m1(i, k)*m2(k, j);
+ return r;
+}
+
+template<typename T, unsigned M, unsigned N>
+inline Vector<T, M> operator*(const Matrix<T, M, N> &m, const Vector<T, N> &v)
+{
+ Vector<T, M> r;
+ for(unsigned i=0; i<M; ++i)
+ for(unsigned j=0; j<N; ++j)
+ r[i] += m(i, j)*v[j];
+ return r;
+}
+
+template<typename T, unsigned M, unsigned N>
+inline Vector<T, N> operator*(const Vector<T, M> &v, const Matrix<T, M, N> &m)
+{
+ Vector<T, N> r;
+ for(unsigned j=0; j<N; ++j)
+ for(unsigned i=0; i<M; ++i)
+ r[j] += v[i]*m(i, j);
+ return r;
+}
+
template<typename T, unsigned M, unsigned N>
inline Matrix<T, M, N> &Matrix<T, M, N>::operator/=(T s)
{
return r -= m2;
}
-template<typename T, unsigned M, unsigned P, unsigned N>
-Matrix<T, M, N> operator*(const Matrix<T, M, P> &m1, const Matrix<T, P, N> &m2)
+template<typename T, unsigned M, unsigned N>
+inline bool operator==(const Matrix<T, M, N> &a, const Matrix<T, M, N> &b)
{
- Matrix<T, M, N> r;
- for(unsigned i=0; i<M; ++i)
- for(unsigned j=0; j<N; ++j)
- for(unsigned k=0; k<P; ++k)
- r.at(i, j) += m1(i, k)*m2(k, j);
- return r;
+ for(unsigned j=0; j<N; ++j)
+ for(unsigned i=0; i<M; ++i)
+ if(a(i, j)!=b(i, j))
+ return false;
+ return true;
}
template<typename T, unsigned M, unsigned N>
-Vector<T, M> operator*(const Matrix<T, M, N> &m, const Vector<T, N> &v)
+inline Matrix<T, M, N> &Matrix<T, M, N>::exchange_rows(unsigned i, unsigned j)
{
- Vector<T, M> r;
- for(unsigned i=0; i<M; ++i)
- for(unsigned j=0; j<N; ++j)
- r[i] += m(i, j)*v[j];
- return r;
+ using std::swap;
+ for(unsigned k=0; k<N; ++k)
+ swap(element(i, k), element(j, k));
+ return *this;
}
template<typename T, unsigned M, unsigned N>
-Vector<T, N> operator*(const Vector<T, M> &v, const Matrix<T, M, N> &m)
+inline Matrix<T, M, N> &Matrix<T, M, N>::multiply_row(unsigned i, T s)
{
- Vector<T, N> r;
+ for(unsigned k=0; k<N; ++k)
+ element(i, k) *= s;
+ return *this;
+}
+
+template<typename T, unsigned M, unsigned N>
+inline Matrix<T, M, N> &Matrix<T, M, N>::add_row(unsigned i, unsigned j, T s)
+{
+ for(unsigned k=0; k<N; ++k)
+ element(j, k) += element(i, k)*s;
+ return *this;
+}
+
+template<typename T, unsigned M, unsigned N>
+inline Matrix<T, N, M> transpose(const Matrix<T, M, N> &m)
+{
+ Matrix<T, N, M> r;
for(unsigned j=0; j<N; ++j)
for(unsigned i=0; i<M; ++i)
- r[j] += v[i]*m(i, j);
+ r(j, i) = m(i, j);
return r;
}
+template<typename T, unsigned M, unsigned N>
+inline std::ostream &operator<<(std::ostream &s, const Matrix<T, M, N> &m)
+{
+ s << "Matrix" << M << 'x' << N << '(';
+ for(unsigned i=0; i<N; ++i)
+ {
+ if(i)
+ s << ", ";
+ s << '[';
+ for(unsigned j=0; j<M; ++j)
+ {
+ if(j)
+ s << ", ";
+ s << m(j, i);
+ }
+ s << ']';
+ }
+ s << ')';
+ return s;
+}
+
} // namespace LinAl
} // namespace Msp