Real values of the W -function
- 1 June 1995
- journal article
- Published by Association for Computing Machinery (ACM) in ACM Transactions on Mathematical Software
- Vol. 21 (2) , 161-171
- https://doi.org/10.1145/203082.203084
Abstract
Approximations for real values of W(x), where W is defined by solutions of W exp(W) = x, are presented. All of the approximations have maximum absolute (|W|1) or relative (|W|O(10−4). With these approximations an efficient algorithm, consisting of a single iteration of a rapidly converging iteration scheme, gives estimates of W(x) accurate to at least 16 significant digits (15 digits if double precision is used). The Fortran code resulting from the algorithm is written to account for the different floating-point-number mantissa lengths on different computers, so that W(x) is computed to the floating-point precision available on the host machine.Keywords
This publication has 4 references indexed in Scilit:
- Algorithm 743: WAPR--a Fortran routine for calculating real values of the W -functionACM Transactions on Mathematical Software, 1995
- A class of exact solutions for Richards' equationJournal of Hydrology, 1993
- Maple V Library Reference ManualPublished by Springer Nature ,1991
- Algorithm 443: Solution of the transcendental equation
we
w
= x
Communications of the ACM, 1973