Customize Polar Axes

Create Polar Plot

Plot a line in polar coordinates and add a title.

theta = linspace(0,2*pi);
rho = 2*theta;
figure
polarplot(theta,rho)
title('My Polar Plot')

Before R2022a, polar axes do not include degree symbols by default. To add them, get the polar axes using pax = gca. Then modify the tick labels using pax.ThetaTickLabel = string(pax.ThetaTickLabel) + char(176).

Customize Polar Axes Using Properties

When you create a polar plot, MATLAB creates a PolarAxes object. PolarAxes objects have properties that you can use to customize the appearance of the polar axes, such as the font size, color, or ticks. For a full list, see PolarAxes Properties.

Access the PolarAxes object using the gca function, such as pax = gca. Then, use pax with dot notation to set properties, such as pax.FontSize = 14.

pax = gca

pax = 
  PolarAxes (My Polar Plot) with properties:

             ThetaLim: [0 360]
                 RLim: [0 14]
       ThetaAxisUnits: 'degrees'
             ThetaDir: 'counterclockwise'
    ThetaZeroLocation: 'right'

  Use GET to show all properties

pax.FontSize = 14;

theta-Axis Tick Values

Display lines along the theta-axis every 45 degrees. Specify the locations as a vector of increasing values.

thetaticks(0:45:315)

Display the theta-axis values in radians instead of degrees by setting the ThetaAxisUnits property.

pax = gca;
pax.ThetaAxisUnits = 'radians';

Modify the theta-axis so that it increases in a clockwise direction. Also, rotate the theta-axis so that the zero reference angle is on the left side.

pax = gca;
pax.ThetaDir = 'clockwise';
pax.ThetaZeroLocation = 'left';

r-Axis Limits, Tick Values, and Labels

Change the limits of the r-axis so that the values range from -5 to 15. Display lines at the values -2, 3, 9, and 15. Then, change the labels that appear next to each line. Specify the labels as a cell array of character vectors.

rlim([-5 15])
rticks([-2 3 9 15])
rticklabels({'r = -2','r = 3','r = 9','r = 15'})

Grid Line and Label Colors

Use different colors for the theta-axis and r-axis grid lines and associated labels by setting the ThetaColor and RColor properties. Change the width of the grid lines by setting the LineWidth property.

Specify the colors using either a character vector of a color name, such as 'blue', or an RGB triplet. An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1], for example, [0.4 0.6 0.7].

pax = gca;
pax.ThetaColor = 'blue';
pax.RColor = [0 .5 0];

Change the color of all the grid lines without affecting the labels by setting the GridColor property.

pax.GridColor = 'red';

When you specify the GridColor property, the ThetaColor and RColor properties no longer affect the grid lines. If you want the ThetaColor and RColor properties to affect the grid lines, then set the GridColorMode property back to 'auto'.