• bandpass(f1, f2, n, [w])—Returns coefficients for a bandpass FIR filter with n coefficients and cutoff frequencies f1 and f2, windowed with taper w.

• bandstop(f1, f2, n, [w])—Returns coefficients for a bandstop FIR filter with n coefficients and cutoff frequencies f1 and f2, windowed with taper w.

• highpass(f, n, [w])—Returns coefficients for a highpass FIR filter with n coefficients and cutoff frequency f, windowed with taper w.

• lowpass(f, n, [w])—Returns coefficients for a lowpass FIR filter with n coefficients and cutoff frequency f, windowed with taper w.

• f, f1, and f2 are real-valued cutoff or bandpass frequencies, given as a fraction of the sampling frequency, between 0 and 0.5.

• n is an integer greater than 2. It represents the number of coefficients for the filter.

• w (optional) is an integer representing a windowing function index. A rectangular window is used if w is 0 or not specified.

• The FIR design functions use windowing of the impulse response of an ideal filter to generate coefficients for an FIR filter of the given type.

• All functions return an n element vector containing the filter coefficients.