Lambert W function for Excel, work on real and complex number

[manandpc]

The Lambert W function (very efficient, fast)

See, LambertW.bas to get the VB module (attach)

Input: real or complex values from -infinity to +infinity
You can verify the results with

=IMSUM(IMPRODUCT(LambertW(COMPLEX(-100,0)),IMEXP(LambertWc(-100,0))),-1)
return:
-100.999999999999+8.5265128291212E-14i

OR

=IMPRODUCT(LambertW(-0.1),IMEXP(LambertW(-0.1)))
return:
-0.1

Lots of testing, no error found

[Onewheeler]

Thank you! That has saved me a lot of work!



Martin/