Is there a clean way to generate a line histogram chart in Python?

DanGoodrick picture DanGoodrick · Jan 10, 2015 · Viewed 48.1k times · Source

I need to create a histogram that plots a line and not a step or bar chart. I am using python 2.7 The plt.hist function below plots a stepped line and the bins don't line up in the plt.plot function.

import matplotlib.pyplot as plt
import numpy as np
noise = np.random.normal(0,1,(1000,1))
(n,x,_) = plt.hist(noise, bins = np.linspace(-3,3,7), histtype=u'step' )  
plt.plot(x[:-1],n)

I need the line to correlate with each bin's count at the bin centers as if there was a histtype=u'line' flag to go with the align=u'mid' flag

Answer

unutbu picture unutbu · Jan 10, 2015

Using scipy, you could use stats.gaussian_kde to estimate the probability density function:

import matplotlib.pyplot as plt
import numpy as np
import scipy.stats as stats

noise = np.random.normal(0, 1, (1000, ))
density = stats.gaussian_kde(noise)
n, x, _ = plt.hist(noise, bins=np.linspace(-3, 3, 50), 
                   histtype=u'step', density=True)  
plt.plot(x, density(x))
plt.show()

enter image description here