def test_simpson_e(self):
"""simpson e should match hand-calculated value"""
# example1 - a totally even community should have simpson_e=1
c = array([1,1,1,1,1,1,1])
self.assertEqual(simpson_e(c), 1)
# example2
c = array([0,30,25,40,0,0,5]).astype(float)
freq_c = c/c.sum()
D = (freq_c**2).sum()
exp = 1./(D*4)
obs = simpson_e(c)
self.assertEqual(obs, exp)
# example3 - from https://groups.nceas.ucsb.edu/sun/meetings/calculating-evenness-of-habitat-distributions
c = array([500, 400, 600, 500])
freq_c = array([.25, .2, .3, .25])
D = .0625+.04+.09+.0625
exp = 1./(D*4)
self.assertEqual(simpson_e(c), exp)
def test_simpson_e(self):
"""simpson e should match hand-calculated value"""
c = array([1,2,3,1])
s = simpson(c)
self.assertEqual((1/s)/4, simpson_e(c))
def test_simpson_e(self):
"""simpson e should match hand-calculated value"""
c = array([1, 2, 3, 1])
s = simpson(c)
self.assertEqual((1 / s) / 4, simpson_e(c))
