NonlinearFit problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg52033] NonlinearFit problem*From*: Feng-Yin Chang <fychang at slac.stanford.edu>*Date*: Mon, 8 Nov 2004 03:13:12 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi All, Could anyone give me any suggestion for the specified fitting function f= r^a Exp[-b r]? My data point was given below, data={{0, 1.00002}, {2.31507, 26.4522}, {4.32033, 56.8265}, {6.63539, 59.6674}, {8.64066, 39.5536}, {10.9557, 21.6862}, {12.961, 10.1456}, {15.276, 4.39652}} The following way, NonlinearFit[data,f,r,{a,b}], gives the error message, FindFit::njnum: The Jacobian is not a matrix of numbers at (a,b)={1.,1.}. How should I do this fitting without the problem? Feng-Yin Chang, Institute of Physics,NCTU,Taiwan

**Follow-Ups**:**Re: NonlinearFit problem***From:*DrBob <drbob@bigfoot.com>