I am creating histogram with
pylab.hist(data,weights,histtype='step',normed=False,bins=150,cumulative=True)
getting (there are other plots, which are irrelevant now) the violet line
Why is the histogram dropping to zero at the end again? Cumulative functions should be in general non-decreasing. Is there a way to work around this, be it bug or feature?
EDIT: solution (hack):
# histtype=step returns a single patch, open polygon n,bins,patches=pylab.hist(data,weights,histtype='step',cumulative=True) # just delete the last point patches[0].set_xy(patches[0].get_xy()[:-1])
This is default behaviour. Think of it as an outline of the histogram as a bar chart. As for a quick workaround, not that I am aware of. A solution would be to calculate the histogram on your own: python histogram one-liner
In case you don't like OP's nice simple solution, here's an over-complicated one where we construct the plot by hand. Maybe it's useful though if you only have access to the histogram counts and can't use matplotlib's hist function.
import numpy as np import matplotlib.pyplot as plt data = np.random.randn(5000) counts, bins = np.histogram(data, bins=20) cdf = np.cumsum(counts)/np.sum(counts) plt.plot( np.vstack((bins, np.roll(bins, -1))).T.flatten()[:-2], np.vstack((cdf, cdf)).T.flatten() ) plt.show()
