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Re: Lorentzian on a baseline

• To: mathgroup at smc.vnet.net
• Subject: [mg89189] Re: [mg89178] Lorentzian on a baseline
• From: Sseziwa Mukasa <mukasa at jeol.com>
• Date: Thu, 29 May 2008 07:01:27 -0400 (EDT)
• References: <200805280845.EAA27166@smc.vnet.net>

On May 28, 2008, at 4:45 AM, fred.engles at gmail.com wrote:

> I'm trying to fit a Lorentzian subtracted from a constant baseline,
> using findfit.
>
>  FindFit[rawdata, m1 - m2/((x - m3)^2 + m2^2), {m1, m2, {m3, 250}}, x,
>   MaxIterations -> 10000]
>
> Isn't working - either a totally flat horizantal line, or the
> subtracted 'Lorentzian' looks almost delta-function sharp. Help?

Your Lorentzian has no amplitude parameter, are you sure it's of  
amplitude 1/m2?

Supplying rawdata would help too, perhaps it's too noisy?

Regards,

Ssezi

• References:
  • Lorentzian on a baseline
    • From: fred.engles@gmail.com