Flattop window

[estarg]

Does anyone have the mathematical definition of the flattop window, sometimes called the Potter 201 window?

 

[WIM32]

calculation flattop window:
(t)=0.2395-0.4581*cos(2**t/T)+0.2585*cos(4**t/T)-0.0439*cos(6**t/T) if 0<t<T otherwise (t)=0

rgrds
Wim

 

[VibEngr]

I'm sorry, but WIM32's formula looks a little strange. There should be a pi and no exponents. Also, the initial constant should be close to unity.

For the P201 window I have:

a0=0.999028
a1=2*0.925752
a2=2*0.351960
a3=0
a4=0

w = a0 - a1*cos(2*pi*t/T) + a2*cos(4*pi*t/T) - a3*cos(6*pi*t/T) + a4*cos(8*pi*t/T)

I hope this helps, Troy

 

[VibEngr]

I almost forgot the last part to normalize the window:

w = w / (a0+a1+a2+a3+a4)

Regards, Troy