Formatting Axis Offset-Values for Whole Numbers or Specific Values

Question:

Consider a matplotlib figure where data values are expressed in nanoseconds (1e-9). If the y-axis displays values like "4.4 with 1e-8 offset," how can the axis be forced to display "44 with 1e-9 offset"? Similarly, if the x-axis displays values like " 5.54478e4," how can it be shown as " 55447" (whole number without decimal)?

Solution:

To achieve the desired formatting, use the following steps:

1. Disable Offset for Scalar Formatters:

from matplotlib.ticker import ScalarFormatter

y_formatter = ScalarFormatter(useOffset=False)
ax.yaxis.set_major_formatter(y_formatter)

This will disable the automatic offset used by matplotlib when displaying scientific notation.

2. Set Number of Significant Figures:

To display whole numbers in the offset without decimals, adjust the number of significant figures:

x_formatter = ScalarFormatter(useOffset=False, useMathText=True)
x_formatter.set_powerlimits((-9,5))  # Display numbers up to 5 significant figures
ax.xaxis.set_major_formatter(x_formatter)