MAtlab的一段程序希望有人解答.
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CHEBY1 Chebyshev Type I digital and analogfilter design.
[B,A] = CHEBY1(N,R,Wp) designs an Nth order lowpass digital Chebyshev
filter with R decibels of peak-to-peak ripple in the passband.CHEBY1
returns the filter coefficients in length N+1 vectors B (numerator) and
A(denominator).The passband-edge frequency Wp must be 0.0 < Wp < 1.0,
with 1.0 corresponding to half the sample rate.Use R=0.5 as a
starting point,if you are unsure about choosing R.
If Wp is a two-element vector,Wp = [W1 W2],CHEBY1 returns an order 2N
bandpass filter with passband W1
< W < W2.[B,A] =
CHEBY1(N,R,Wp,'high') designs a highpass filter.[B,A] =
CHEBY1(N,R,Wp,'low') designs a lowpass filter.[B,A] =
CHEBY1(N,R,Wp,'stop') is a bandstop filter if Wp = [W1 W2].
When used with three left-hand arguments,as in [Z,P,K] = CHEBY1(...),
the zeros and poles are returned in length N column vectors Z and P,
and the gain in scalar K.
When used with four left-hand arguments,asin [A,B,C,D] = CHEBY1(...),
state-space matrices are returned.
CHEBY1(N,R,Wp,'s'),CHEBY1(N,R,Wp,'high','s') and
CHEBY1(N,R,Wp,'stop','s') design analog Chebyshev Type I filters.In
this case,Wp is in [rad/s] and it can be
greater than 1.0