Nth order Butterworth low pass filter design

I have been given the order N = 6 and the cutoff freqency as 1 rad/sec. Then what should be Wn , that I have to put in the function [b,a]= butter(N, Wn)?

Answer 1

[Star Strider]

Since in radian measure the frequency is defined on the interval , and 1 is obviously in that interval, use 1 as ‘Wn’, since that is the normalised frequency (as described in the documentation).