Rotating a turtle through cone of vision - netlogo

Question

I wish to write to where I have a cone-of-vision cone angle for the turtle.
And I rotate the turtle through the cone-of-vision.
Therefore, first it's heading the start of cone-of-vision and with a increment of 0.05 degree it changes till it reaches the end of cone-of-vision
let max-head heading + (cone-angle / 2)
set heading subtract-headings heading (zero-dash / 2)
while[(subtract-headings heading max-head ) < 0]
[
set heading heading + .05
;wait 0.1
]
The above code I wrote isnt correct. But I can't find the mistake.

Answer 1

I think part of your difficulty is using subtract-headings. This finds the size of the shortest angle between two headings and that's not what you want for a cone of vision (which could potentially be wide). Since your code rotates clockwise, I have assumed you want to start at the most anti-clockwise point and rotate. The only difficulty then is if the heading goes through 360, so you need to separate the cone sweeping counter and the actual heading, and use mod arithmetic to convert from the counter.
globals
[ cone-angle]
to setup
clear-all
create-turtles 1
set cone-angle 25
end
to go
ask turtles
[ let max-head heading + (cone-angle / 2)
let fake-head heading - (cone-angle / 2)
while [fake-head < max-head]
[ print fake-head
set fake-head fake-head + 1
set heading fake-head mod 360
wait 0.1
]
]
end