11/06/2007, 01:34 PM

Ivars Wrote:Im (W) = +- ipi/2

then branches k=-1 and k=+1 are accordingly

-i(pi/2 - 2pi) = - 5/2pi i ; +i(pi/2+2pi) = + 5/2 pi*i and so on for all branches.

Again, no! Try for example Maple (LambertW) or Mathematica (ProductLog), you can chose the branch there, for example

Code:

`LambertW(-3,-Pi/2)=-2.198342630-13.98120831*I`

LambertW(-2,-Pi/2)=-1.604290913-7.647192276*I

LambertW(-1,-Pi/2)=-1.570796327*I

LambertW(0,-Pi/2)=1.570796327*I

LambertW(1,-Pi/2)=-1.604290913+7.647192276*I

LambertW(2,-Pi/2)=-2.198342630+13.98120831*I

The numbering of the branches is of course convention, but seems to match we the one given in your article (which seems to be a quite good article).