Digital Signal Processing Reference
In-Depth Information
>> mymax(x2)
ans =
4.5000
4. Find y
1
[n] = x
1
[n]:9x
1
[n1], using x
1
from above.
Plot y
1
(adjusting t as needed).
Answer:
Array t does not need to be adjusted, but we have to be careful about n. That
is, x
1
[n1] does not exist when n = 1 (MATLAB will not let us index an
array at location 0). Therefore, we have to start n at 2, so that n1 is a valid
array value. Also, notice that we use parentheses for MATLAB code, in place
of the square brackets.
for n=2:length(x1)
y1(n) = x1(n) - .9 * x1(n-1);
end
plot(y1)
5. Create y
2
[n] to be the average of the current and previous two values of x
2
[n].
Plot y
2
.
Answer:
We have to be careful with our starting value for n, as in the problem above.
for n=3:length(x2)
y2(n) = (x2(n) + x2(n-1) + x2(n-2))/3;
end
plot(y2)
6. Create y
3
[n] = x
2
[n]y
3
[n1].
Plot y
3
.
What will happen as n approaches innity?
