comp.lang.idl-pvwave archive: archive » Re: ProductLog function

Home » Public Forums » archive » Re: ProductLog function

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: ProductLog function [message #60105 is a reply to message #60103]

Thu, 01 May 2008 06:26

pgrigis
Messages: 436
Registered: September 2007

Senior Member

You could try to use a numerical solver like fx_root in IDL.

Ciao,
Paolo

emitch...@googlemail.com wrote:
> Hi all, I've used Wolfrang Mathmatica to solve an equation for x, and
> have been given a solution involving the function ProductLog. I was
> wondering if anyone knew if there was any inbuilt capacity in IDL to
> evaluate this. It's definitely different to PRODUCT(ALOG(x)), as I've
> tried this but results were wrong.
>
> I'm trying to convert a matrix of y's to x's, but the equation I need
> to use is:
>
> y = 0.0015x + a(1-exp(-bx))
>
> Mathmatica gave me (to 6sf):
>
> 0.333333(-2000.a + 2000.y +
> (3.ProductLog(666.667(a.b.exp(666.667b(1.a-1.y)))))/b
>
> I tried this in IDL, but no joy:
>
> (1D/3D)*(-2000D*a + 2000D*y + (3*(PRODUCT(ALOG((2000D/
> 3D)*a*b*exp((2000D/3D)*b*((a-1D)*(y))))))/b))
>
> Cheers,
>
> Ed

Report message to a moderator

[Message index]

		Re: ProductLog function By: Jeremy Bailin on Fri, 02 May 2008 07:46
		Re: ProductLog function By: Allan Whiteford on Thu, 01 May 2008 06:36
		Re: ProductLog function By: Vince Hradil on Thu, 01 May 2008 06:35
		Re: ProductLog function By: pgrigis on Thu, 01 May 2008 06:26

Previous Topic:	iImage axes
Next Topic:	Re: A problem using IDL?

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Oct 10 15:24:39 PDT 2025

Total time taken to generate the page: 0.96056 seconds