Function Sine Wave

//@version=4
study(title='Function Sine Wave')
wave_height = input(100)
wave_duration = input(50)

f_sine_wave_1(_wave_height, _wave_duration) =>
    _pi = 3.14159265359
    _w = 2 * _pi / _wave_duration
    _sine_wave = _wave_height * sin(_w * bar_index)
    _sine_wave
f_sine_wave_2(_wave_height, _wave_duration) =>
    _pi = 3.14159265359
    _w = 2 * _pi / _wave_duration
    _sine_wave = _wave_height * sin(_w * bar_index)
    _sine_wave

wave = f_sine_wave_1(wave_height, wave_duration)
wave2 = f_sine_wave_2(wave_height, close)
plot(series=wave, title='Normal', color=color.black)
plot(series=wave2, title='Price as cycle duration', color=color.red)
//end of this part

length = input(50)
src = wave
//----
sum=0.,sumw=0.
for i = 1 to length
    w = sin(2*3.14*i/length)/i
    sumw := sumw + w
    sum := sum + w*src[i-1]
//----
plot(sum/sumw,"Plot",#ff1100,2,transp=0)