def METHOD_NAME(x, y, rho0, e1=0, e2=0, center_x=0, center_y=0):
    """Projected density.
    :param x:
    :param y:
    :param rho0:
    :param e1:
    :param e2:
    :param center_x:
    :param center_y:
    :return:
    """
    x_ = x - center_x
    y_ = y - center_y
    r = np.sqrt(x_**2 + y_**2)
    sigma = np.pi * rho0 / r
    return sigma