matrix3x3.h

#ifndef CMU462_MATRIX3X3_H
#define CMU462_MATRIX3X3_H

#include <iosfwd>

#include "vector3D.h"

namespace CMU462 {  

class Matrix3x3 {
  
  public:

  void zero(double val = 0.0 );

  double det( void ) const;

  double norm( void ) const;

  static Matrix3x3 identity( void );

  static Matrix3x3 crossProduct( const Vector3D& u );

        Vector3D& column( int i );
  const Vector3D& column( int i ) const;

  Matrix3x3 T( void ) const;

  Matrix3x3 inv( void ) const;

  // accesses element (i,j) of A using 0-based indexing
        double& operator()( int i, int j );
  const double& operator()( int i, int j ) const;

  // accesses the ith column of A   
        Vector3D& operator[]( int i );
  const Vector3D& operator[]( int i ) const;

  // increments by B
  void operator+=( const Matrix3x3& B );

  // returns -A
  Matrix3x3 operator-( void ) const;

  // returns A-B
  Matrix3x3 operator-( const Matrix3x3& B ) const;

  // returns c*A
  Matrix3x3 operator*( double c ) const;

  // returns A*B
  Matrix3x3 operator*( const Matrix3x3& B ) const;

  // returns A*x
  Vector3D operator*( const Vector3D& x ) const;

  // divides each element by x
  void operator/=( double x );   

  protected:

  // column vectors
  Vector3D entries[3];

}; // class Matrix3x3

// returns the outer product of u and v
Matrix3x3 outer( const Vector3D& u, const Vector3D& v );

// returns c*A
Matrix3x3 operator*( double c, const Matrix3x3& A );

// prints entries
std::ostream& operator<<( std::ostream& os, const Matrix3x3& A );
    
} // namespace CMU462

#endif // CMU462_MATRIX3X3_H