Section: Handle-Based Graphics
legend command are supported.  The
first form creates a legend with the given labels for the data
series:
  legend('label1','label2',...)
where 'label1' is the text label associated with data plot 1
and so on.  You can also use the legend command to control
the appearance of the legend in the current plot.  To remove the
legend from the current plot, use
  legend('off')
To hide the legend for the current plot (but do not remove it)
  legend('hide')
And to show the legend that has been hidden, use
  legend('show')
You can also toggle the display of the box surrounding the legend. Use
  legend('boxoff')
or
  legend('boxon')
to turn the legend box off or on, respectively. To toggle the visible state of the current legend, use
  legend('toggle')
Specifying no arguments at all (apart from an optional location argument as specified below) results in the legend being rebuilt. This form is useful for picking up font changes or relocating the legend.
legend
By default, the legend command places the new legend in the 
upper right corner of the current plot.  To change this behavior,
use the 'location' specifier (must be the last two options to the command)
legend(...,'location',option)
where option takes on the following possible values
north,N - top center of plot 
 south,S - bottom center of plot
 east,E - middle right of plot
 west,W - middle left of plot
 northeast,NE - top right of plot (default behavior)
 northwest,NW - top left of plot
 southeast,SE - bottom right of plot
 southwest,SW - bottom left of plot
 legend is incomplete relative to the 
MATLAB API.  The functionality will be improved in future versions
of FreeMat.