/// <summary>
/// 2Dベクトルの原点中心の回転を行います
/// </summary>
/// <param name="theta"></param>
/// <returns></returns>
public Pos Rotation2DVector(double theta)
{
return(new Pos(
x * Cal.Cos(theta) - y * Cal.Sin(theta),
x * Cal.Sin(theta) + y * Cal.Cos(theta)
));
}
/// <summary>
/// 回転
/// </summary>
public static Pos Rotation(double theta)
{
return(new Pos(Cal.Cos(theta), Cal.Sin(theta)));
}