One value not being displayed?

Hello. I was wondering why one of my values isn't being displayed?

The value of '1' in the first graph (Magnitude Coefficients).

Code:

n_1 = 3:4:20;
n_2 = 0:2:20;
n_3 = 1:4:20;

s1 = n_3;
s2 = n_2==0;
s3 = n_1;

f(s1) = 4./(pi*s1).*sin(s1*pi/2);
f(s2) = 0;
f(s3) = -4./(pi*s3).*sin(s3*pi/2);

theta(n_3) = 0;
theta(n_1) = -pi;

subplot (2,1,1); stem(n_3, f(s1), 'p')
hold on
subplot (2,1,1); stem(n_1, f(s3), 'b'); ylabel('c_n'); xlabel('n'); title ('Magnitude Coefficients')

subplot (2,1,2); stem (n_3, theta(n_3), 'm')
hold on
subplot (2,1,2) ; stem (n_1, theta(n_1), 'g'); ylabel('\theta(n) [rad]'); xlabel('n') ; title ('Phase Coefficients')

Please and thank you.

Answer 1

[Chad Greene]

You've overwritten f(1) when you set f(s2)=0; Replace your first stem line with the values directly:

stem(n_3, 4./(pi*s1).*sin(s1*pi/2), 'p')

[Annalise]

That worked... thank you ^^ I repositioned the values, so that f(s2) is taken in first, and it came out right.

[Chad Greene]

Great!

Answer 2

[Image Analyst]

It is being displayed. f(1) is zero, and there is a marker at y=0 for the x=1 index.

[Annalise]

Yeah, but it wasn't the value I was supposed to get ^^ It was supposed to be x(1) = 1.27. Thank you though! ^^