Numerical evaluation of harmonic polylogarithms

Harmonic polylogarithms H((a) over right arrow ;x), a generalization of Nielsen's polylogarithms S-n,S-p(x), appear frequently in analytic calculations of radiative corrections in quantum field theory. We present an algorithm for the numerical evaluation of harmonic polylogarithms of arbitrary real argument. This algorithm is implemented into a FORTRAN subroutine hplog to compute harmonic polylogarithms up to weight 4. (C) 2001 Elsevier Science B.V. All rights reserved.