def test_mean() :
h0 = Histogram(axis=Axis(100, -50, 50))
h1 = Histogram(axis=Axis(100, -50, 50))
for x in xrange(-50, 50) :
h0.fill(x + 0.5)
if x + 0.5 > 0 :
h1.fill(x+0.5)
assert h1.mean() == 25.
assert h0.mean() == 0
def test_empty_histogram() :
h = Histogram(axis=Axis(100,-50, 50))
assert h.entries() == 0.
assert h.sigma() == 0
assert h.mean() == 0
assert h.overflow() == 0
assert h.underflow() ==0
