We present a reliable and portable software package for computing zeros of
analytic functions. The package is named ZEAL (ZEros of Analytic functions)
. Given a rectangular region W in the complex plane and a function f: W -->
C that is analytic in W and does not have zeros on the boundary of W, ZEAL
localizes and computes all the zeros of f that lie inside W, together with
their respective multiplicities. ZEAL is based on the theory of formal ort
hogonal polynomials. It proceeds by evaluating numerically certain integral
s along the boundary of W involving the logarithmic derivative f'/f and by
solving generalized eigenvalue problems. The multiplicities are computed by
solving a linear system of equations that has Vandermonde structure. ZEAL
is written in Fortran 90. (C) 2000 Elsevier Science B.V. All rights reserve
d.