/// <summary>
/// returns <paramref name="a"/>*<paramref name="alpha"/>
/// </summary>
/// <param name="a">a vector field</param>
/// <param name="alpha">scalar</param>
/// <returns></returns>
static public VectorField <T> operator *(VectorField <T> a, double alpha)
{
VectorField <T> ret = (VectorField <T>)a.Clone();
ret.Scale(alpha);
return(ret);
}
/// <summary>
/// subtracting two vector fields
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
/// <returns></returns>
static public VectorField <T> operator -(VectorField <T> a, VectorField <T> b)
{
VectorField <T> ret = (VectorField <T>)b.Clone();
ret.Scale(-1);
ret.Acc(1.0, a);
return(ret);
}
