MATLAB: Plotting over a certain range, what am i doing wrong here

arraymatrix arraymatrix manipulationplotting

I am looking to plot this sinusoidal curve over just a desired range, from theta=120 to theta=150 here
It must be zero before 120 and after 150
The code is as written below,
x = 0:0.1:3.14;
y = sin(x);
theta = 0:360;
if theta(theta(1,:)<120) && theta(theta(1,:)>150)
    yy = 0;
else
    yy = y;
end
plot(theta,yy)
Its returning me errors saying,
Operands to the || and && operators must be convertible to logical scalar values.
How do i approach this problem?

Best Answer

Mixing radian and degree angle units makes this a bit more challenging.
Try this: 
yfcn = @(a) sin(a) .* ((120*pi/180 < a) & (150*pi/180 > a));
x = 0:0.1:pi;
figure
plot(x, yfcn(x))
grid
Note that in your original code, ‘theta’ and ‘x’ are vastly different sizes, so the plot would never work regardless. Beyond that, to compare vector elements, use single logical operators, not double logical operators.
.
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