Axes Aspect Ratio Properties

The axis command works by setting various axes object properties. You can set these properties directly to achieve precisely the effect you want.

When the mode properties are set to auto, MATLAB automatically determines values for all of these properties and then stretches the axes to fit the figure shape. You can override any property's automatic operation by specifying a value for the property or setting its mode property to manual.

The value you select for a particular property depends primarily on what type of data you want to display. Much of the data visualized with MATLAB is either

In the first case, it is generally desirable to select axis limits that provide good resolution in each axis direction and to fill the available space. Real-world objects, on the other hand, need to be represented accurately in proportion, regardless of the angle of view.

The MATLAB default property values are designed to

Default Aspect Ratio Selection

The axes Position property specifies the location and dimensions of the axes within the figure. The third and fourth elements of the Position vector (width and height) define a rectangle in which MATLAB draws the axes. MATLAB fits the axes to this rectangle.

The default value for the axes Units property is normalized to the parent figure dimensions. This means the shape of the figure window determines the shape of the position rectangle. As you change the size of the figure window, MATLAB reshapes the position rectangle to fit it.

sphere
set(gcf,'Color',[0.90 0.90 0.90])
set(gca,'BoxStyle','full','Box','on')

Changing the size and shape of the figure causes a change in the size and shape of the axes. The axes might select new axis tick mark locations as well.

f = gcf;
f.Position(3) = f.Position(3) * 0.67;

Reshaping the axes to fit into the figure window can change the aspect ratio of the graph. MATLAB fits the axes to fill the position rectangle and in the process can distort the shape. This is generally desirable for graphs of numeric data, but not for displaying objects realistically.

Maintaining the Axes Proportions with Figure Resize

To maintain a particular shape, you can specify the size of the axes in absolute units such as inches, which are independent of the figure window size. However, this is not a good approach if you are writing a MATLAB program that you want to work with a figure window of any size. A better approach is to specify the aspect ratio of the axes and override automatic stretch-to-fill.

In cases where you want a specific aspect ratio, you can override stretching by specifying a value for these axes properties:

The first two sets of properties affect the aspect ratio directly. Setting either of the mode properties to manual simply disables stretch-to-fill while maintaining all current property values. In this case, MATLAB enlarges the axes until one dimension of the position rectangle constrains it. For example, set the DataAspectRatio to [1 1 1]. Also set the figure's color to see the relationship between the figure and the axes.

sphere
daspect([1 1 1])
set(gca,'BoxStyle','full','Box','on')
set(gcf,'Color',[0.90 0.90 0.90])

Changing the size and shape of the figure does not change the aspect ratio of the axes.

f = gcf;
f.Position(3) = f.Position(3) * 0.67;

Setting the CameraViewAngle property disables stretch-to-fill, and also prevents MATLAB from readjusting the size of the axes if you change the view.

Aspect Ratio Properties

It is important to understand how properties interact with each other, in order to obtain the results you want. The DataAspectRatio, PlotBoxAspectRatio, and the x-, y-, and z-axis limits (XLim, YLim, and ZLim properties) all place constraints on the shape of the axes.

[X,Y] = meshgrid((-2:.15:2),(-4:.3:4));
Z = X.*exp(-X.^2 - Y.^2);
surf(X,Y,Z)
set(gca,'BoxStyle','full','Box','on')

daspect

ans = 1×3

     4     8     1

daspect([1 1 1])

pbaspect

ans = 1×3

     4     8     1

daspect([1 1 1])
pbaspect([1 1 1])

set(gca,'DataAspectRatio',[1 1 1],...
        'PlotBoxAspectRatio',[1 1 1],...
        'XLim',[-4 4],...
        'YLim',[-4 4],...
        'ZLim',[-1 1])

pbaspect

ans = 1×3

     4     4     1

Displaying Real Objects

If you want to display an object so that it looks realistic, you need to change MATLAB defaults. For example, this data defines a wedge-shaped patch object.

vert = [0 0 0; 0 1 0; 1 1 0; 1 0 0; 0 0 1; 0 1 1; 1 1 4; 1 0 4];
fac = [1 2 3 4; 2 6 7 3; 4 3 7 8; 1 5 8 4; 1 2 6 5; 5 6 7 8];
patch('Vertices',vert,'Faces',fac,...
   'FaceColor',[0.7 0.7 0.7],'EdgeColor','k')
view(3)

However, this axes distorts the actual shape of the solid object defined by the data. To display it in correct proportions, set the DataAspectRatio. Setting this property makes the units equal in the x-, y-, and z-directions and prevents the axes from being stretched to fill the position rectangle, revealing the true shape of the object.

set(gca,'DataAspectRatio',[1 1 1])