1、butter函数中~analog是什么意思?
% step 1: get analog, pre-warped frequencies
if ~analog,
fs = 2;
u = 2*fs*tan(pi*Wn/fs);
else
u = Wn;
end
2、butter函数中step3为什么要转换到状态空间?
% step 3: Get N-th order Butterworth analog lowpass prototype
[z,p,k] = buttap(n);
% Transform to state-space
[a,b,c,d] = zp2ss(z,p,k);
谢谢各位!!!