cla deletes all graphics objects that have
visible handles from the current axes. The handle is visible if the HandleVisibility property
of the object is set to 'on'.

The next plot added to the axes uses the first color and line
style based on the ColorOrder and LineStyleOrder properties
of the axes. The cla command resets the ColorOrderIndex and LineStyleOrderIndex properties
of the current axes to 1.

cla reset deletes graphics objects from
the current axes regardless of their handle visibility. It also resets
axes properties to their default values, with the exception of the Position and Units properties.

cla(ax) deletes all
graphics objects that have visible handles from the axes specified
by ax instead of the current axes. The next plot
added to the axes uses the first color and line style based on the ColorOrder and LineStyleOrder properties
of the axes.

cla(ax,'reset') deletes
graphics objects from the axes specified by ax,
regardless of their handle visibility. It also resets axes properties
to their default values, with the exception of the Position and Units properties.

Plot two sine waves. Then, clear the line plots from the axes.

x = linspace(0,2*pi);
y1 = sin(x);
y2 = sin(2*x);
plot(x,y1)
hold on
plot(x,y2)

cla

cla clears the line plots and resets the ColorIndex and LineStyleIndex properties of the axes to 1. Subsequent plots start from the beginning of the color order and line style order. For example, plot another sine wave.

Now, reset all axes properties for the upper subplot, including the camera properties that control the view, by using the optional input argument 'reset'.

x = linspace(0,2*pi);
y = sin(x);
plot(x,y)
axis([0,5,-2,2])

Clear the line plot from the axes and reset all the axes properties to their default values. cla reset resets all properties of the current axes, except for the Position and Units properties.

cla only deletes objects with a HandleVisibility property
set to 'on'. Therefore, if the HandleVisibility of
an object is set to 'callback' and you are in a
callback, then cla does not delete it.