iFit/allometric

 y = allometric(p, x, [y]) : Power/Freundlich/Belehradek function

   iFunc/allometric Power/Freundlich/Belehradek fitting function
                    to describe power and asymptotic laws
     y = p(1)*(x-p(2)).^p(3) + p(4);

 allometric(decay)          creates a model with specified decay constant
 allometric([ parameters ]) creates a model with specified model parameters

 Reference: Ratkowksy, David A. 1990. Handbook of Nonlinear Regression Models. Marcel Dekker, Inc. 4.3.1 

 input:  p: Power model parameters (double)
            p = [ Amplitude Offset Exponent BackGround ]
          or 'guess'
         x: axis (double)
         y: when values are given and p='guess', a guess of the parameters is performed (double)
 output: y: model value
 ex:     y=allometric([1 0 1 1], -10:10); or plot(allometric)

 Version: Aug. 22, 2017
 See also iFunc, iFunc/fits, iFunc/plot
 (c) E.Farhi, ILL. License: EUPL.