1994/10/01 by J. A. C. Weideman · 3 citations
Computer Science · Mathematics · #Digital Filter Design and Implementation #Numerical Methods and Algorithms #Numerical methods for differential equations
paper · doi:10.1137/0731077
openalex publication_date 1994/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Rational expansions for computing the complex error function w(z) = e - z2 erfc( - iz) are presented. These expansions have the following attractive properties: (1) they can be evaluated using a polynomial evaluation routine such as Homer’s method, (2) the polynomial coefficients can be computed once and for all by a single Fast Fourier Transform (FFT), and (3) high accuracy is achieved uniformly in the complex plane with only a small number of terms. Comparisons reveal that in some parts of the complex plane certain competitors may be more efficient. However, the difference in efficiency is never great, and the new algorithms are simpler than existing ones: a complete program takes eight lines of Matlab code.