iFit/langevin

 y = langevin(p, x, [y]) : Langevin function for magnetic polarization

   iFunc/langevin Langevin function for magnetic polarization
     x = (x-p(2))/p(3); y  = p(4)+ p(1) .* ( coth(x) - 1./x );

 langevin(centre)         creates a model with a specified centre/threshold
 langevin([ parameters ]) creates a model with specified model parameters

 input:  p: Langevin model parameters (double)
            p = [ Amplitude Center Width 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=langevin([1 0 1 1], -10:10); or plot(langevin);

 Version: Nov. 26, 2018
 See also iFunc, iFunc/fits, iFunc/plot
 (c) E.Farhi, ILL. License: EUPL.