def test_size_distribution_n_part():
# Arrange
s = 1.5
n_part = 256
sut = Lognormal(n_part, .5e-5, s)
# Act
m, dm = np.linspace(.1e-6, 100e-6, 100, retstep=True)
sd = sut.size_distribution(m)
# Assert
assert_approx_equal(np.sum(sd) * dm, n_part, 4)
def test_size_distribution_r_mode():
# Arrange
s = 1.001
r_mode = 1e-6
sut = Lognormal(1, r_mode, s)
# Act
m, dm = np.linspace(.01e-6, 100e-6, 10000, retstep=True)
sd = sut.size_distribution(m)
# Assert
assert_approx_equal(m[sd == np.amax(sd)], r_mode, 2)