% b = firls(N, F, A); % b = firls(N, F, A, W); % % FIR filter design using least squares method. Returns a length N+1 % linear phase filter such that the integral of the weighted mean % squared error in the specified bands is minimized. % % F specifies the frequencies of the band edges, normalized so that % half the sample frequency is equal to 1. Each band is specified by % two frequencies, to the vector must have an even length. % % A specifies the amplitude of the desired response at each band edge. % % W is an optional weighting function that contains one value for each % band that weights the mean squared error in that band. A must be the % same length as F, and W must be half the length of F.