Errorbar Limit Selection

Introduction

In data visualization, it is often necessary to show the degree of uncertainty in the data being plotted. Error bars are a convenient way to represent this uncertainty. In this lab, we will learn how to selectively draw lower and/or upper limit symbols on error bars using the parameters uplims and lolims in Matplotlib.

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Import the necessary libraries

In this step, we import the necessary libraries to create our plots.

import matplotlib.pyplot as plt
import numpy as np

Create the data

In this step, we create the data that we will use to create our error bar plot.

x = np.arange(10)
y = 2.5 * np.sin(x / 20 * np.pi)
yerr = np.linspace(0.05, 0.2, 10)

Create the error bar plot with both limits (default)

In this step, we create an error bar plot with both upper and lower limits, which is the default behavior.

plt.errorbar(x, y + 3, yerr=yerr, label='both limits (default)')

Create the error bar plot with upper limits only

In this step, we create an error bar plot with only upper limits.

plt.errorbar(x, y + 2, yerr=yerr, uplims=True, label='uplims=True')

Create the error bar plot with both upper and lower limits

In this step, we create an error bar plot with both upper and lower limits.

plt.errorbar(x, y + 1, yerr=yerr, uplims=True, lolims=True, label='uplims=True, lolims=True')

Create the error bar plot with subsets of upper and lower limits

In this step, we create an error bar plot with subsets of upper and lower limits.

upperlimits = [True, False] * 5
lowerlimits = [False, True] * 5
plt.errorbar(x, y, yerr=yerr, uplims=upperlimits, lolims=lowerlimits, label='subsets of uplims and lolims')

Create the error bar plot with horizontal error bars

In this step, we create an error bar plot with horizontal error bars.

x = np.arange(10) / 10
y = (x + 0.1)**2

plt.errorbar(x, y, xerr=0.1, xlolims=True, label='xlolims=True')
y = (x + 0.1)**3

plt.errorbar(x + 0.6, y, xerr=0.1, xuplims=upperlimits, xlolims=lowerlimits, label='subsets of xuplims and xlolims')

y = (x + 0.1)**4
plt.errorbar(x + 1.2, y, xerr=0.1, xuplims=True, label='xuplims=True')

Add a legend and show the plot

In this step, we add a legend to the plot and display it.

plt.legend(loc='lower right')
plt.show()

Summary

In this lab, we learned how to selectively draw lower and/or upper limit symbols on error bars using the parameters uplims and lolims in Matplotlib. We also learned how to create error bar plots with horizontal error bars.