Subject: Generalized Lambert W function - premature commit
From: Robert Dodier
Date: Thu, 17 May 2012 04:31:13 +0000 (UTC)
On 2012-05-17, David Billinghurst <dbmaxima at gmail.com> wrote:
> Oops. I have accidentally committed some code for Generalized Lambert
> W function to src/specfn.lisp. Still getting my head around git.
> The code seems functionally correct, and passes tests in
> tests/rtest_lambert_w.mac, but I hadn't finished polishing it and it
> is still undocumented. Unless anyone objects, I will leave it in
> place for the time being.
No problem, OK by me.
> There is a new function generalized_lambert_w(k,z) that returns the
> kth branch W_k(z). There are float and bigfloat routines for complex
> z. generalized_lambert_w(0,z) is not (yet) simplified to
> lambert_w(z), as I hadn't decided if this should be done
> unconditionally or controlled by a flag. Thoughts?
Is it more convenient to simplify W_0(z) instead of W(z) ? If not, then
it seems reasonable to just go ahead and simplify it.
If you decide against automatically simplifying W_0(z) to W(z), I guess
I hope you don't make it controlled by a flag; flags cause trouble,
because one can't guess by looking at some code how it's going to turn
out. How about a function to carry out the simplification.
Thanks for your work on this topic.
Robert Dodier