PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

40 Practical MATLAB® Applications for Engineers

title (‘2 triangular cycles’);

axis ([0 1 -0.5 1.5]);

ylabel (‘Amplitude’) ;

xlabel (‘time’);

The script fi le triang_pulses is executed and the results are shown in Figure 1.36.

R.1.119 Recall that system concepts such as transfer function, fi lter, and input and output
signals were introduced in Chapter 7 of the book titled Practical MATLAB® Basics
for Engineers.
The MATLAB command [h, t] = impulse(P, Q, t) returns as output h, when the
input is a Dirac impulse applied to a fi lter or system whose transfer function is
given by P/Q, where P and Q are polynomials expressed as row arrays whose coef-
fi cients are arranged in descending order of s (where s = jw is the Laplace variable)
and t is the time interval of interest (see Chapter 4 for more information).

R.1.120 The MATLAB command [gs, t] = step(P, Q, t) returns the step response of a linear
system with a transfer function defi ned by H = P/Q, over a time interval t.

R.1.121 The MATLAB function hn = dimpulse(P, Q, n) returns the discrete impulse response
consisting of n samples, applied to the discrete transfer function H(z) = P(z)/Q(z),
where P(z) and Q(z) represent the vector polynomial consisting of its coeffi cients
arranged in decreasing powers of z, where z = ejw.*

*^ See Chapter 5 for more information about z.

3 triangular cycles

5 triangular cycles

4 triangular cycles

2 triangular cycles

1.5

0.5

1.5 1.5

1

1

0.5

1

0

−0.5

0.5

−0.5

0

1

Amplitude

Amplitude Amplitude

Amplitude

0

0

0.5

0.5

1

1

1.5

0.5

−0.5

0.5^1

0

0

1

0

0

−0.5

0.5

time time

FIGURE 1.36
Plots of R.1.118.