def test_Euler():
"""
This test checks that the Euler method is correctly updating a particle's position and
velocity.
"""
proton = Particle('proton', const.m_p, [0,0,0], [-100,200,300], [10,20,-30])
deltaT = 0.5
calculated_position = np.array([-50,100,150], dtype=float)
calculated_velocity = np.array([-95,210,285], dtype=float)
proton.euler(deltaT)
assert np.array_equal(calculated_position,proton.position)
assert np.array_equal(calculated_velocity,proton.velocity)
