How to extract one of the histogram plots resulting from using pd.Dataframe.hist()?-CodePudding

when I use the hist() from Pandas it produces a series of histograms for all the features in the dataset. I want to know how to extract/select/reference only one of the histograms returned by hist()?

For example, let'say I have the following code:

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

df = pd.DataFrame({'X' : np.random.rand(100), 'Y': np.random.rand(100)})
df
df.hist()

array([[<matplotlib.axes._subplots.AxesSubplot object at 0x00000150DAC658C8>,
        <matplotlib.axes._subplots.AxesSubplot object at 0x00000150DB29AD48>]],
      dtype=object)

I have tried slicing the array of matplotlib axes returned by the hist() method using [] (i.e. df.hist()[0]), but it does not extract only one plot but the two of them.

CodePudding user response：

I believe you can pass in a column name to hist() in order to select one of the histograms.

df.hist(column = column_name)

CodePudding user response：

I want to know how to extract:

df['X'].hist()

I want to know how to reference:

The ndarray of subplots returned is two-dimensional here, so:

axs = df.hist()
axs[0, 0].set_xlim(0, 2) # modify leftmost subplot

or .flatten() first:

axs.flatten()[0].set_xlim(0, 2)

CodePudding user response：

Try this:

h = plt.hist(df)

h
(array([[15., 13., 11.,  9.,  2., 15., 10.,  4.,  9., 12.],
        [ 6., 14., 10.,  9.,  9., 13., 11.,  7.,  8., 13.]]),
 array([0.01212735, 0.11088648, 0.20964561, 0.30840474, 0.40716387,
        0.50592301, 0.60468214, 0.70344127, 0.8022004 , 0.90095953,
        0.99971866]),
 <a list of 2 BarContainer objects>)

counts, bins, ax = h
counts
array([[15., 13., 11.,  9.,  2., 15., 10.,  4.,  9., 12.],
       [ 6., 14., 10.,  9.,  9., 13., 11.,  7.,  8., 13.]])
bins
array([0.01212735, 0.11088648, 0.20964561, 0.30840474, 0.40716387,
       0.50592301, 0.60468214, 0.70344127, 0.8022004 , 0.90095953,
       0.99971866])
ax
<a list of 2 BarContainer objects>

Slice counts and bins as needed.