Page 125 - Basics of MATLAB and Beyond

delete(h(1:2))
We can now issue the correct text command:

text(-.7,f(-.7),’f(x)’)

Let us write an m-file to do this automatically. We’ll call it oops. When
we call oops without any argument, it should delete the last object
drawn in the current axes. When called with an integer argument, n,
oops should delete the last n objects drawn in the current axes. The
following m-file is a possible solution. (The function nargin returns the
number of arguments with which a function was called.)

function oops(N)

% OOPS Delete the last object plotted on the axes.
% Repeating "oops" erases farther back in time.
% OOPS does not work for title and labels; to
% erase these, use "title(’’)" or "xlabel(’’)"
if nargin = =0N=1;end
h = get(gca,’children’);
delete(h(1:N));
Let us see if oops works:

clf
plt(x,f(x))
hold on
plt(x,f(x/2))

Nowwedoan oops to get rid of the shallow parabola,

oops

Now plot the shallow one again with a different line style:

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