Create an input array from -1*pi to 1*pi

% Create an input array from -1*pi to 1*pi
t=[3 4 5 6 7 8 9];
% Calculate |sin(t)|
x=abs(sin(t));
%plot result
plot(t,x);

Answer 1

[Walter Roberson]

% Create an input array from -1*pi to 1*pi
t=-pi:pi;
% Calculate |sin(t)|
x=abs(sin(t));
%plot result
plot(t,x);

[Jan]

And with a finer grid:

t = -pi:0.01:pi;  % But this does not match the endpoint exactly!
t = linspace(-pi, pi, 200);  % See: doc linpsace

[Aaron Kerr]

Thank you, for my lerning and understanding, if the -1*pi to 1*pi was changed to other numbers say -3 and 3 would t=-3pi:3pi; and where does the t=[3 4 5 6 7 8 9]; factor in.

[Walter Roberson]

3 4 5 etc does not fit at all.

linspace(-3*pi,3*pi)

[Aaron Kerr]

Thanks, what about if it was t=[0 1 2 3 4 5 6]; what is the "t" refering to.

[Torsten]

If you set

t=[0 1 2 3 4 5 6];
x=abs(sin(t));
plot(t,x)

MATLAB takes the point (0,abs(sin(0))), (1,abs(sin(1))),...,(6,abs(sin(6))) and connects them in this order by straight lines in the plot.

Same for any array t that you define in advance.