Can someone please explain why my function wont plot correctly

clear all
t=0:10;
y=-2:0.5:2

y = 1×9

-2.0000 -1.5000 -1.0000 -0.5000 0 0.5000 1.0000 1.5000 2.0000

fig1=0.001*sin((2*t)+(pi/2));
plot (fig1), grid on

Answer 1

[Dyuman Joshi]

You need atleast 2 sets of values to plot a graph.

I assume you want to plot fig1 against t

t=0:10;
fig1=0.001*sin((2*t)+(pi/2));

plot(t, fig1)
grid on

You can also plot a smooth graph for the same relation via fplot -

fun = @(t) 0.001*sin((2*t)+(pi/2));
fplot(fun,[0 10])

If this is not what you want, please specify what you want to plot.

[Daniel]

thank you thats what i needed

[Dyuman Joshi]

@Daniel, if this answer solved your problem, please consider accepting it.

Answer 2

[Sulaymon Eshkabilov]

You'd need to take a bit small step size for t to make your plot look like a sine wave:

clear all
dt=0.1;
t=0:dt:10;
fig1=0.001*sin((2*t)+(pi/2));
figure(1)
plot(t, fig1, 'ro--'), grid on
xlabel('t')
ylabel('y(t)')

%% Alt. way is:
y=@(t)0.001*sin((2*t)+(pi/2));
N = 200;   % Number of points
t = linspace(0, 10, N);
figure(2)
plot(t, y(t), 'kd--'), grid on
xlabel('t')
ylabel('y(t)')