// $Id: CovMatrix2VectorMultiply.cc,v 1.4 2002/09/19 16:45:18 sachs Exp $
//  David Sachs, Fermilab - April 2002
#include "CovMatrices/CovMatrix2.h"
#include "CovMatrixElement.h"

// Functions for multiplying a CovMatrix2 by a Vector2 or a BiVector2
// These functions are very straightforward, but contain too many operations to
// justify making them inline

namespace CovMatrices
{
  Vector2 operator* ( const CovMatrix2& m, const   Vector2& v )
  {
    return Vector2(
  	m.M[M00]*v.E[0] + m.M[M01]*v.E[1],
  	m.M[M10]*v.E[0] + m.M[M11]*v.E[1]);
  }
  
  Vector2 operator* ( const Vector2& v, const CovMatrix2& m )
  {
    return Vector2(
  	m.M[M00]*v.E[0] + m.M[M01]*v.E[1],
  	m.M[M10]*v.E[0] + m.M[M11]*v.E[1]);
  }
  
  BiVector2 operator* ( const CovMatrix2& m, const BiVector2& b )
  {
    return BiVector2(
  	m.M[M00]*b.v0.E[0] + m.M[M01]*b.v0.E[1],
  	m.M[M10]*b.v0.E[0] + m.M[M11]*b.v0.E[1],
  	m.M[M00]*b.v1.E[0] + m.M[M01]*b.v1.E[1],
  	m.M[M10]*b.v1.E[0] + m.M[M11]*b.v1.E[1]); 
  }
  
  BiVector2 operator* ( const BiVector2& b, const CovMatrix2& m )
  {
    return BiVector2(
  	m.M[M00]*b.v0.E[0] + m.M[M01]*b.v0.E[1],
  	m.M[M10]*b.v0.E[0] + m.M[M11]*b.v0.E[1],
  	m.M[M00]*b.v1.E[0] + m.M[M01]*b.v1.E[1],
  	m.M[M10]*b.v1.E[0] + m.M[M11]*b.v1.E[1]);
  }
}