Custom Ticker1

The new ticker code was designed to explicitly support user customized ticking. The documentation of matplotlib.ticker details this process. That code defines a lot of preset tickers but was primarily designed to be user extensible.

In this example a user defined function is used to format the ticks in millions of dollars on the y axis.

import matplotlib.pyplot as plt

money = [1.5e5, 2.5e6, 5.5e6, 2.0e7]


def millions(x, pos):
    """The two args are the value and tick position."""
    return '${:1.1f}M'.format(x*1e-6)

fig, ax = plt.subplots()
# Use automatic FuncFormatter creation
ax.yaxis.set_major_formatter(millions)
ax.bar(['Bill', 'Fred', 'Mary', 'Sue'], money)
plt.show()

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References

The use of the following functions, methods, classes and modules is shown in this example:

import matplotlib
matplotlib.pyplot.subplots
matplotlib.axis.Axis.set_major_formatter
matplotlib.ticker.FuncFormatter