geomean = []
for value in values:
a =Y[np.where(feature == value)]
- a = np.array(map(lambda x : x**(1.0/len(a)), a))
+ a = np.array(list(map(lambda x : x**(1.0/len(a)), a)))
geomean.append(a.prod())
plt.plot(feature, Y, 'r.')
for ii in range(0, len(geomean)-1):