Graphics Programs Reference

In-Depth Information

text(-.7,f(-.7),'f(X)')

But we have made a mistake: the “x” should be lower case. We try to

correct it by issuing another
text
command with a lower case “x”:

text(-.7,f(-.7),'f(x)')

But this has printed over the top of the previous label, making a mess.

Without starting again, we can use the
delete
function to delete the

text objects, once we know their handles. We can get a list of the handles

of the line and the text objects by getting all the children of the current

axes:

>> h = get(gca,'children')

h=

19.0001

18.0001

11.0005

The variable
h
is a three-element column vector (the actual values are

not important). These are the handles corresponding to the Line object

(parabola) and the two Text objects. But which of them is the Line

object and which are the Text objects? We can get the object types

corresponding to these handles by typing:

>> types = get(h,'type')

types =

'text'

'text'

'line'

(The variable
types
is returned as a cell array.) A parent's children

are always listed in reverse age order: the most recently drawn object

appears first—youngest first, oldest last. This tells us that the first two

elements of the vector
h
correspond to the text objects '
f(X)
' and '
f(x)
',

in that order, and the third element corresponds to the parabolic line.

We can delete the two text objects by typing: