Matplotlib.ticker.FuncFormatter class in Python
Last Updated :
25 Apr, 2025
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Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack.
matplotlib.ticker.FuncFormatter
The matplotlib.ticker.FuncFormatter class uses a user defined function for formatting. This user defined function must take two values as inputs for a tick value x and a position pos.
Syntax: class matplotlib.ticker.FuncFormatter(func)
Parameter:
- func: The user defined function for formatting of the plot.
Example 1:
Python3
import matplotlib.pyplot as pltimport matplotlib.ticker as tickimport numpy as npx = np.linspace(0, 10, 1000)y = 0.000001 * np.sin(10 * x)fig = plt.figure()ax = fig.add_subplot(111)ax.plot(x, y)def y_fmt(x, y): return '{:2.2e}'.format(x).replace('e', 'x10^')ax.yaxis.set_major_formatter(tick.FuncFormatter(y_fmt))plt.show() |
Output:
Example 2:
Python3
import matplotlib.pyplot as pltfrom matplotlib.ticker import FuncFormatterfig, ax = plt.subplots()ax.axis([0.01, 10000, 1, 1000000])ax.loglog()for axis in [ax.xaxis, ax.yaxis]: formatter = FuncFormatter(lambda y, _: '{:.16g}'.format(y)) axis.set_major_formatter(formatter)plt.show() |
Output:
