Here is another (warped ;-) perspective:

def func1(p)
  (p >  100) ? "right" :
  (p > -100) ? "center":
               "left"
end

def func2(r1, r2, p)
  (p > r2) ? "right" :
  (p > r1) ? "center":
             "left"
end

p func1(200)  # -> "right"
p func1(-50)  # -> "center"
p func1(-200) # -> "left"

p func2(-300, 300,  400) # -> "right"
p func2(-300, 300,  -50) # -> "center"
p func2(-300, 300, -400) # -> "left"