I need to repeat a periodic signal

The function is

f(t) = -t/2 if -2<=t<0

f(t) = t if 0<=t<1

f(t) = 1 if 1<=t<2

The periode is 4

and it has to be repeated from -10 to 10

Answer 1

[Image Analyst]

This looks like a homework problem. If you have any questions ask your instructor or read the link below to get started:

How do I get help on homework questions on MATLAB Answers? - MATLAB Answers - MATLAB Central

Obviously we can't give you the full solution because you're not allowed to turn in our code as your own.

Hint: linspace to generate t, and repmat to make additional copies of a vector.

Use masking to get the ranges of indexes for t and don't use (t) when assigning f, use the mask, like

t = linspace(..................); % You finish it
f = zeros(1, numel(t)); % Initialize
indexesToAssign = (-2 <= t) & (t < 0); % Get logical vector (mask) of where these indexes are.
f(indexesToAssign) = -t/2;
% Similar for the two other ranges.

Answer 2

[Walter Roberson]

Hint:

syms t
F(t) = piecewise(-2 <= t & t < 0, 1, 0 <= t & t < 1, 2, 1 <= t & t < 2, 3)

F(t) = 

fplot(F, [-10 10]); ylim([-1 4])

G = F(mod(t,4)-2)

G = 

fplot(G, [-10 10]); ; ylim([-1 4])

This tells us that if you can construct f(t) for one period of t, then you can extend it to an indefinite number of periods using mod

[ALOUI]

That worked for me very well Thank you so much

[Paul]

@Walter Roberson

I don't think the expression for G is correct. G should overlay F in the range -2<t<2.

syms t
F(t) = piecewise(-2 <= t & t < 0, 1, 0 <= t & t < 1, 2, 1 <= t & t < 2, 3);
G(t) = F(mod(t,4)-2);
figure
fplot([G F],[-10 10],'ShowPoles','off')
ylim([0 4])

[Walter Roberson]

Good catch, @Paul

syms t
F(t) = piecewise(-2 <= t & t < 0, 1, 0 <= t & t < 1, 2, 1 <= t & t < 2, 3);
G(t) = F(mod(t+2,4)-2);
figure
fplot([G F],[-10 10],'ShowPoles','off')
ylim([0 4])