thetaregion

Create a polar plot. Then create a filled wedge between the angles 0 and pi/2.

% Create polar plot
theta = 0:0.01:2*pi;
rho = 2*sin(2*theta).*cos(2*theta);
polarplot(theta,rho,LineWidth=1.5)

% Create wedge
theta1 = 0;
theta2 = pi/2;
thetaregion(theta1,theta2)

Change the theta-axis units to radians by setting the ThetaAxisUnits property.

pax = gca;
pax.ThetaAxisUnits = "radians";

Create three filled wedges by specifying the theta values as three-element vectors.

theta1 = [pi/3 7*pi/6 10*pi/6];
theta2 = [pi/2 4*pi/3 11*pi/6];
thetaregion(theta1,theta2)

Alternatively, specify one 2-by-3 matrix of theta values.

figure
T = [pi/3 7*pi/6 10*pi/6; pi/2 4*pi/3 11*pi/6];
thetaregion(T)

You can specify PolarRegion properties, such as face color and boundary line width and color, by specifying one or more name-value arguments when you call thetaregion. Alternatively, you can set properties of the PolarRegion object after creating it.

For example, create two green filled wedges: one in the first (upper-right) quadrant and the other in the third (lower-left) quadrant. Specify an output argument to store the PolarRegion objects so that you can modify them later.

theta1 = [0 pi];
theta2 = [pi/2 3*pi/2];
tr = thetaregion(theta1,theta2,FaceColor="g");

Change the color of the wedge in the third quadrant to a shade of purple by setting the FaceColor property to a hexadecimal color code. Then display thick boundary lines on the wedge in the first quadrant by setting the EdgeColor property to a value other than "none" and LineWidth property to 1.5 points.

% Set color of wedge in third quadrant
tr(2).FaceColor = "#5500FF";

% Set boundary color and line thickness in first quadrant
tr(1).EdgeColor = "b";
tr(1).LineWidth = 1.5;

Plot a blue and a red cardioid.

theta = linspace(0,2*pi);
rho1 = 1-cos(theta);
rho2 = 1-cos(theta+pi);

% Blue cardioid
cardioid1 = polarplot(theta,rho1,LineWidth=1.5);
hold on

% Red cardioid
cardioid2 = polarplot(theta,rho2,LineWidth=1.5);

Create wedges that highlight specific regions of each cardioid.

theta1 = 5*pi/6;
theta2 = 7*pi/6;
wedge1 = thetaregion(theta1,theta2);

theta3 = 11*pi/6;
theta4 = 13*pi/6;
wedge2 = thetaregion(theta3,theta4);

Match each wedge color to the corresponding cardioid by setting the SeriesIndex property of the wedge to the SeriesIndex property of the cardioid.

wedge1.SeriesIndex = cardioid1.SeriesIndex;
wedge2.SeriesIndex = cardioid2.SeriesIndex;

To move a wedge on top of a plot, set the Layer property of the PolarRegion object to "top". For example, plot a polar rose and add a filled wedge. When you create the wedge, specify a custom face color and a transparency value so that you can see that the rose is on top of the wedge.

% Plot polar rose
theta = 0:0.01:2*pi;
rho = sin(2*theta).*cos(2*theta);
polarplot(theta,rho,LineWidth=1.5)

% Add filled wedge
theta1 = 0;
theta2 = pi/4;
tr = thetaregion(theta1,theta2,FaceColor=[0.8 0.8 0.8],FaceAlpha=0.7);

Move the filled wedge on top of the rose by setting the Layer property to "top".

tr.Layer = "top";

To create filled wedges in different polar axes within the same figure, create a tiled chart layout. In this case, create two axes that each contain a filled wedge.

Use the tiledlayout function to create a 1-by-2 tiled chart layout t. Use the polaraxes function to create each PolarAxes object. By default, both objects occupy the first tile. Move the second PolarAxes object to the second tile by setting the Layout.Tile property.

t = tiledlayout(1,2);
pax1 = polaraxes(t);
pax2 = polaraxes(t);
pax2.Layout.Tile = 2;

Create a red wedge in the first polar axes, and create a green wedge in the second polar axes. Specify the PolarAxes object that you want to plot into as the first argument when you call thetaregion.

theta1 = 0;
theta2 = pi/4;
thetaregion(pax1,theta1,theta2,FaceColor="r")
thetaregion(pax2,theta1,theta2,FaceColor="g")