How to remove an histogram in Matplotlib

Question

I am used to work with plots that change over the time in order to show differences when a parameter is changed. Here I provide an easy example

import matplotli         


        

Answer 1

Here the right way to iteratively draw and delete histograms in matplotlib

import matplotlib.pyplot as plt
import numpy as np


fig = plt.figure(figsize = (20, 10))
ax = fig.add_subplot(111)
ax.grid(True)


for j in range(1, 15):
    x = np.random.randn(100)
    count, bins, bars = ax.hist(x, 40)
    plt.draw()
    plt.pause(1.5)
    t = [b.remove() for b in bars]

Answer 2

ax.hist doesn't return what you think it does.

The returns section of the docstring of hist (access via ax.hist? in an ipython shell) states:

Returns
-------
n : array or list of arrays
    The values of the histogram bins. See **normed** and **weights**
    for a description of the possible semantics. If input **x** is an
    array, then this is an array of length **nbins**. If input is a
    sequence arrays ``[data1, data2,..]``, then this is a list of
    arrays with the values of the histograms for each of the arrays
    in the same order.

bins : array
    The edges of the bins. Length nbins + 1 (nbins left edges and right
    edge of last bin).  Always a single array even when multiple data
    sets are passed in.

patches : list or list of lists
    Silent list of individual patches used to create the histogram
    or list of such list if multiple input datasets.

So you need to unpack your output:

counts, bins, bars = ax.hist(x, 40)*j
_ = [b.remove() for b in bars]