2D Plots - Fancy Graphic Tool
Matlab includes
fancy tools for visualization. Basic 2D plots, good 3D
graphics, and even animation possibilities are available
in an easy environment.
The most basic and useful command for producing simple 2D
plots is:
plot(
xvalues,
yvalues, '
style')
-
xvalues is the
value of the
horizontal points
to be plotted.
-
yvalues is the
value of the
function to be
plotted.
-
xvalues and
yvalues have to
have the same length.
-
' style' is an
optional argument that specifies the
color,
line style and
point-marker
style.
Examples:
plot(x,y) |
plots y vs
x with a
solid line
|
plot(x,y,'-.') |
plots y vs
x with a
dash-dot line
|
plot(x) |
plots the elements of
x against
their own index
|
plot(x,y,'r--') |
plots y vs
x with a red
dashed line
|
plot(a,b,'k+') |
plots b vs
a
with black plus signs
|
You may annotate your plots with '
xlabel', '
ylabel' and '
title'. Other useful
functions are '
legend', '
axis', '
grid' and '
hold'.
Here's an example that integrates all of the above
functions.
% Clears variables, command window, and closes all
figures
clear, clc,close all
% Defines value of x and two functions
x = 0: .1 : 2*pi;
y1 = cos(x);
y2 = sin(x);
% Plots two functions with different style, and wider
lines
plot(x,y1,'b', x, y2, 'r-.', 'linewidth', 2)
% Activates the grid
grid on
% Defines limits for x and y axes, and sets title, labels
and legends
axis([0 2*pi -1.5 1.5])
title('2D plots', 'fontsize', 12)
xlabel('angle')
ylabel('f1(x), f2(x)')
legend('cos(x)', 'sin(x)')
% Keeps figure on screen, in order to add a third
function
hold on
% Defines another function
y3 = 0.5 * x;
% Plots over the previous figure
plot(x, y3, 'm')
And the result is:
|
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|
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