function N = kaiord(Fp, Fs, Rp, Rs, FT)% Computation of the length of a linear-phase% FIR multi-band filter using Kaiser's formula% % Rp is the passband ripple% Rs is the stopband ripple% Fp is the passband edge in Hz% Fs is the stopband edge in Hz% FT is the sampling frequency in Hz.  % If none specified default value is 2% N is the estimated FIR filter orderif nargin == 4,	FT = 2;endif length(Fp) > 1,	TBW = min(abs(Fp(1) - Fs(1)), abs(Fp(2) - Fs(2)));else	TBW = abs(Fp - Fs);endnum = -20*log10(sqrt(Rp*Rs))-13;den = 14.6*TBW/FT;N = ceil(num/den);