- A histogram is a frequency plot. Each interval data is marked with different heights based on the frequency of the data in that interval. Higher the frequency greater the height marked for that frequency.
- Calling the hist() method on the plot member of a DataFrame instance draws the histogram for each column present in the DataFrame.
- Number of bins or intervals of the histogram is specified for all the columns of the DataFrame combined.
- Each histogram will be drawn in an overlapping(if any) fashion using the alpha-blending value specified.
# Example Python program that plots
# histograms for weekly data
import pandas as pds
import matplotlib.pyplot as plot
dailyClosingPrices = [(10.2, 9.8),
# The index
index = ["Mon", "Tue", "Wed", "Thu", "Fri"];
# Column labels
columns = ["Week1", "Week2"];
# Create a DataFrame instance
df = pds.DataFrame(data=dailyClosingPrices, index = index, columns = columns);
# Draw histograms for weekly closing prices
df.plot.hist(bins=4, alpha=0.5, title="Weekly Histograms for daily closing prices");