Axes Aspect Ratio

By default, 2-D graphs display in a rectangular axes that has the same aspect ratio as the figure window. This makes optimum use of space available for plotting. Set the aspect ratio with the axis function:

  • axis normal — Sets the axis limits to span the data range along each axis and stretches the plot to fit the figure window. This the default behavior.

  • axis square — makes the current axes region square

  • axis equal — sets the aspect ratio so that the data units are the same in every direction

  • axis equal tight — sets the aspect ratio so that the data units are the same in every direction and then sets the axis limits to the minimum and maximum values of the data.

For example, these statements create a elongated circle.

t = 0:pi/20:2*pi;
x = sin(t);
y = 2*cos(t);
plot(x,y)
grid on

These graphs show the effects of various axis command options:

3-D Views

These statements create a cylindrical surface:

t = 0:pi/6:4*pi;
[x,y,z] = cylinder(4+cos(t),30);
surf(x,y,z)

These graphs show the effects of various axis command options:

  • axis normal — Sets the axis limits to span the data range along each axis and stretches the plot to fit the figure window. This the default behavior.

  • axis square — Creates an axes that is square regardless of the shape of the figure window. The cylindrical surface is no longer distorted because it is not warped to fit the window. However, the size of one data unit is not equal along all axes (the z-axis spans only one unit while the x-axes and y-axes span 10 units each).

  • axis equal — Makes the length of one data unit equal along each axis while maintaining a nearly square plot box. It also prevents warping of the axis to fill the window's shape.

  • axis vis3d — Freezes aspect ratio properties to enable rotation of 3-D objects and overrides stretching the axes to fill the figure. Use this option to keep settings from changing while you rotate the scene.

    Note:   To format aspect ratio using the axis function, call axis after creating the graph or use the hold on command before plotting data.

Additional Commands for Setting Aspect Ratio

You can also control the aspect ratio of your graph more precisely using these functions:

  • Specifying the relative scales of the x-, y-, and z-axes (data aspect ratio)

  • Specifying the shape of the space defined by the axes (plot box aspect ratio)

  • Specifying the axis limits

The following commands enable you to set these values.

Command

Purpose

daspect

Set or query the data aspect ratio

pbaspect

Set or query the plot box aspect ratio

xlim

Set or query x-axis limits

ylim

Set or query y-axis limits

zlim

Set or query z-axis limits

Was this topic helpful?