In this post, we will see an example of how to make histogram with Matplotlib library in Python. Matplotlib’s pyplot module is designed to make a number of types of plots with Matplotlib. We will use pyplot module’s function hist() to make histograms with matplotlib.
Let us load Matplotlib.pyplot and Numpy library.
1 2 | import matplotlib.pyplot as pltimport numpy as np |
We will generate data to make a histogram using NumPy’s random module. Here were using NumPy.random’s normal distribution function to generate random numbers for our data.
1 2 3 4 5 6 7 8 9 10 | # set seed for reproducingnp.random.seed(42)# specify meanmean_mu = 60specify Standard deviationsd_sigma = 15# number of data pointsn = 5000# generate random numbers from normal distributiondata = np.random.normal(mean_mu, sd_sigma, n) |
Matplotlib’ Pyplot has hist() function that takes the data as input and makes histogram. In addition to data, hist() function can take a number of arguments to customize the histogram.
Here we specify the number of bins with “bins=100″ argument and specify we want frequency histogram with ” density=False” argument. We also specify transparency levels for the fill color with alpha=0.75.
1 2 3 4 5 | # the histogram of the datan, bins, patches = plt.hist(data, bins=100, density=False, alpha=0.75)plt.xlabel('data',size=16)plt.ylabel('Counts',size=16)plt.title('Histogram with Matplotlib',size=18) |
pyplot’s hist function also returns three tuples with all the information needed for histogram. And be default, pyplot’s hist() function colors the histogram in blue as shown below.
