Functions > Signal Processing > Digital Filtering > About Digital Filtering Functions
  
About Digital Filtering Functions
The following functions are used in the design of Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) filters.
• gain—Returns the gain of a filter.
• response, fftfilt—Returns the response of a vector to a FIR or IIR filter.
• bandpass, bandstop, highpass, lowpass—Returns coefficients for a bandpass, bandstop, highpass, or lowpass of an FIR filter.
• remez—Returns coefficients for an FIR filter generated by the Remez exchange algorithm.
• bessel, butter, cheby1, cheby2—Returns coefficients for a Bessel filter, a Butterworth filter or a Chebyshev filter of Type I or II.
• iirhigh, iirlow, iirpass, iirstop—Returns coefficients for a highpass, lowpass, bandpass, or bandstop of an IIR filter.
• filtfilt—Returns the zero-phase response of a filter.
• grpdelay—Returns the group delay imposed by a filter.
• upsample, multirate, resample—Performs interpolation and then resampling of an array.