(5)Details about this crucial optimization step can be found in the bibliographic references. While a thorough discussion of the algorithm is beyond the scope of the book, we can mention that at each iteration the new set of candidate extremal points is obtained by exchanging the old set with the ordinates of the current local maxima. This trick is known as the Remez exchange algorithm and that is why, in Matlab, the Parks-McClellan algorithm is named remez.