X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;ds=sidebyside;f=source%2Flinal%2Fmatrix.h;h=2ad03447a9b10454f73ab982cf49f26dd25f983f;hb=HEAD;hp=ff73165d02c703c0efe263b27f23a522c54b7383;hpb=b60ee0fb060790277bfc68722f85a137a58ad771;p=libs%2Fmath.git

diff --git a/source/linal/matrix.h b/source/linal/matrix.h
index ff73165..2ad0344 100644
--- a/source/linal/matrix.h
+++ b/source/linal/matrix.h
@@ -2,17 +2,22 @@
 #define MSP_LINAL_MATRIX_H_
 
 #include <algorithm>
+#include <ostream>
+#include "matrixops.h"
 #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];
 
@@ -22,22 +27,38 @@ public:
 	template<typename U>
 	Matrix(const Matrix<U, M, N> &);
 
+	static Matrix identity();
 	static Matrix from_columns(const Vector<T, M> *);
 	static Matrix from_rows(const Vector<T, N> *);
 
+	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*=(const Matrix &);
 	Matrix &operator/=(T);
 	Matrix &operator+=(const Matrix &);
 	Matrix &operator-=(const Matrix &);
 
-	Matrix &exchange_rows(unsigned, unsigned);
-	Matrix &multiply_row(unsigned, T);
-	Matrix &add_row(unsigned, unsigned, T);
+	Matrix &invert();
+
+	Matrix &exchange_columns(unsigned, unsigned);
+	Matrix &multiply_column(unsigned, T);
+	Matrix &add_column(unsigned, unsigned, T);
 };
 
 template<typename T, unsigned M, unsigned N>
@@ -54,9 +75,21 @@ inline Matrix<T, M, N>::Matrix(const T *d)
 
 template<typename T, unsigned M, unsigned N>
 template<typename U>
-inline Matrix<T, M, N>::Matrix(const Matrix<U, M, N> &m)
+inline Matrix<T, M, N>::Matrix(const Matrix<U, M, N> &other)
+{
+	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 Matrix<T, M, N> Matrix<T, M, N>::identity()
 {
-	std::copy(m.data, m.data+M*N, data);
+	static_assert(M==N, "An identity matrix must be square");
+	Matrix<T, M, N> m;
+	for(unsigned i=0; i<M; ++i)
+		m(i, i) = T(1);
+	return m;
 }
 
 template<typename T, unsigned M, unsigned N>
@@ -66,6 +99,7 @@ inline Matrix<T, M, N> Matrix<T, M, N>::from_columns(const Vector<T, M> *v)
 	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>
@@ -75,6 +109,29 @@ inline Matrix<T, M, N> Matrix<T, M, N>::from_rows(const Vector<T, N> *v)
 	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>
@@ -85,6 +142,13 @@ inline Matrix<T, M, N> &Matrix<T, M, N>::operator*=(T s)
 	return *this;
 }
 
+template<typename T, unsigned M, unsigned N>
+inline Matrix<T, M, N> &Matrix<T, M, N>::operator*=(const Matrix<T, M, N> &m)
+{
+	static_assert(M==N, "Multiplication-assignment is only possible on square matrices");
+	return *this = *this*m;
+}
+
 template<typename T, unsigned M, unsigned N>
 inline Matrix<T, M, N> operator*(const Matrix<T, M, N> &m, T s)
 {
@@ -174,6 +238,23 @@ inline Matrix<T, M, N> operator-(const Matrix<T, M, N> &m1, const Matrix<T, M, N
 	return r -= m2;
 }
 
+template<typename T, unsigned M, unsigned N>
+inline Matrix<T, M, N>& Matrix<T, M, N>::invert()
+{
+	static_assert(M==N, "Inversion is only possible on square matrices");
+	Matrix<T, M, N> r = identity();
+	gauss_jordan(*this, r);
+	return *this = r;
+}
+
+template<typename T, unsigned S>
+inline Matrix<T, S, S> invert(const Matrix<T, S, S> &m)
+{
+	Matrix<T, S, S> temp = m;
+	Matrix<T, S, S> r = Matrix<T, S, S>::identity();
+	return gauss_jordan(temp, r);
+}
+
 template<typename T, unsigned M, unsigned N>
 inline bool operator==(const Matrix<T, M, N> &a, const Matrix<T, M, N> &b)
 {
@@ -185,26 +266,27 @@ inline bool operator==(const Matrix<T, M, N> &a, const Matrix<T, M, N> &b)
 }
 
 template<typename T, unsigned M, unsigned N>
-inline Matrix<T, M, N> &Matrix<T, M, N>::exchange_rows(unsigned i, unsigned j)
+inline Matrix<T, M, N> &Matrix<T, M, N>::exchange_columns(unsigned i, unsigned j)
 {
-	for(unsigned k=0; k<N; ++k)
-		std::swap(element(i, k), element(j, k));
+	using std::swap;
+	for(unsigned k=0; k<M; ++k)
+		swap(element(k, i), element(k, j));
 	return *this;
 }
 
 template<typename T, unsigned M, unsigned N>
-inline Matrix<T, M, N> &Matrix<T, M, N>::multiply_row(unsigned i, T s)
+inline Matrix<T, M, N> &Matrix<T, M, N>::multiply_column(unsigned i, T s)
 {
-	for(unsigned k=0; k<N; ++k)
-		element(i, k) *= s;
+	for(unsigned k=0; k<M; ++k)
+		element(k, i) *= 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)
+inline Matrix<T, M, N> &Matrix<T, M, N>::add_column(unsigned i, unsigned j, T s)
 {
-	for(unsigned k=0; k<N; ++k)
-		element(j, k) += element(i, k)*s;
+	for(unsigned k=0; k<M; ++k)
+		element(k, j) += element(k, i)*s;
 	return *this;
 }
 
@@ -218,6 +300,27 @@ inline Matrix<T, N, M> transpose(const Matrix<T, M, N> &m)
 	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