Description

Here we will show how to make contour plots in sage for functions with two variables, such as

Sage Cell

Code

y = var('y')
contour_plot(x^2 + y^2, (x, -10, 10), (y, -10, 10))

Options

Multicolor plots

By using the cmap option, we can make a contour plot in multiple different colors instead of shades:

Code

y = var('y')
contour_plot(x^2 + y^2, (x, -10, 10), (y, -10, 10), cmap='jet')

Adding a legend

We can also set colorbar to True for a legend to increase readability

Code

y = var('y')
contour_plot(x^2 + y^2, (x, -10, 10), (y, -10, 10), cmap='jet', colorbar=True)

Fill, Axes and Labels

When creating a contour plot, you can set the fill, axes and labels properties to True or False (Their default values are True, False and False, respectively). If you're setting axes or labels to True, it's a good idea to set fill to False, otherwise the fill will cover them up.

Code

y = var('y')
contour_plot(x^2 + y^2, (x, -10, 10), (y, -10, 10), fill=False, axes=True, labels=True)

Tags

Primary Tags: Plotting: Two-dimensional plots

Secondary Tags: Two-dimensional plots: Contour plots

Related Cells

• Plotting a Circle
• Plotting a Polygon
• Plotting an Implicit Function
• Two-Dimensional Plots
• Parametric Plots
• Line Plots
• Plotting Two-Dimensional Vector Fields
• Multiple Plots on the Same Graph
• Controlling the Viewing Window of a Plot
• Plotting Functions with Asymptotes
• Multiple Annotation Techniques for Graphing
• Occasional Issues in Polar Plotting.
• Plotting Inequalities in Sage
• Plotting Systems of Linear Inequalities
• Plotting Nonlinear Inequalities in Sage
• Making log-log Plots in Sage

Attribute

Permalink:

Author: Gregory V. Bard. Sage for Undergraduates. American Mathematical Society, Providence, RI, 2015. Available at http://www.gregorybard.com/Sage.html.

Date: 28 Feb 2019 21:50

Submitted by: Zane Corbiere