Pulse shaping filter program that finds the pole-zero locations of a transfer function, H(s), for a matched filter. H(s) equals a -desired- signal (Yout) divided by a given input signal (Yin). Both Yout and Yin are functions of frequency. Group delay may also be calculated to compliment a given data set, thus, providing a flat group delay. Minimizing Intersymbol Interference in a read/write channel for disc drives by shaping and slimming an isolated readback pulse was the main objective for writing this program. For more info, see Kost, R. and P. Brubaker; 'Arbitrary equalization with simple LC structures'; IEEE Transactions on Magnetics, Nov. 1981, pp 3346-3348 or visit http://www.digitalcalculus.com/page/785704. This is a Fortran Calculus demo application.