Matlab Chapter6.pdf

Example 1.4 The characters \ pi create the symbol π.
Example 1.5
≫ xlabel( ′ x = 0 : 2\pi ′ )
≫ ylabel( ′ Sine of x ′ )
≫ title( ′ Plot of the Sine Function’,’FontSize ′ , 12)
≫ t = −pi : pi/100 : pi;
≫ y = sin(t);
≫ plot(t, y)
≫ axis([−pi pi − 1 1])
≫ xlabel( ′ −\pi ≤ t ≤ \pi ′ )
≫ ylabel( ′ sin(t) ′ )
≫ title(’Graph of the sine function’)
≫ text(1, −1/3, ′ Notetheoddsymmetry. ′ )
You can also set these options interactively. Note that the location of the text string is defined
in axes units (i.e., the same units as the data).
Remark 1.2 Graphs may be labeled with the following statements:
≫ gtext(text)
writes a string (text) in the graph window. gtext puts a cross-hair in the graph window
and waits for a mouse button or keyboard key to be pressed. The cross-hair can be positioned
with the mouse or the arrow keys. For example,
≫ gtext(Xmarksthespot)
Text may also be placed on a graph interactively with Tools click Edit Plot from the figure
window.
≫ text(x, y, text)
writes text in the graphics window at the point specified by x and y.
If x and y are vectors, the text is written at each point. If the text is an indexed list,
successive points are labeled with corresponding rows of the text.
≫ title(text)
1.8 Figure Windows
Graphing functions automatically open a new figure window if there are no figure windows
already on the screen. If a figure window exists, MATLAB uses that window for graphics
output. If there are multiple figure windows open, MATLAB targets the one that is designated
the “current figure” (the last figure used or clicked in).
To make an existing figure window the current figure, you can click the mouse while the
pointer is in that window or you can type
≫ figure(n)
where n is the number in the figure title bar. The results of subsequent graphics commands
are displayed in this window.
≫ x = 0 : pi/100 : 2 ∗ pi;
≫ y = sin(x);
≫ y2 = sin(x − .25);
≫ y3 = sin(x − .5);
≫ plot(x, y)
≫ plot(x, y2)
≫ plot(x, y3)
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