Displaying first decimal digit in scientific notation in Matplotlib

Question

I am currently generating different figures with a scientific notation for the y-axis leading to ticks like 2 or 6 on some plots, but 2.5 or 8.9 on some others. I would like to

Answer 1

The ScalarFormatter does not currently support custom formats for the ticks, such as setting numbers of decimals. However you can extend the class, so to force it to use a format that you specify. Here is an example:

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.ticker import ScalarFormatter

class ScalarFormatterForceFormat(ScalarFormatter):
    def _set_format(self):  # Override function that finds format to use.
        self.format = "%1.1f"  # Give format here

plt.plot(np.arange(1, 10), np.arange(1, 10)**5)
ax = plt.gca()
yfmt = ScalarFormatterForceFormat()
yfmt.set_powerlimits((0,0))
gca().yaxis.set_major_formatter(yfmt)
plt.show()

Here is how it will look.