Hi,
      I am trying to fit a Johnson SB distribution using fitdist function in
fitdistrplus Library. I have defined the Johnson SB distribution from (
http://www.ntrand.com/johnson-sb-distribution/) . But it gives me the
follwing errors. Any help would be appreciated

#xi = xi
#lambda =l
#delta =d
#gamma = g

djohn = function(x,xi,l,d,g)
(d/(l*sqrt(2*pi)*((x-xi)/l)*(1-((x-xi)/l))))*exp[-0.5*(g +
d*log(((x-xi)/l)/(1-((x-xi)/l))))^2]

pjohn = function(x,xi,l,d,g)   pnorm(g + d*log(((x-xi)/l)/(1-((x-xi)/l))))

qjohn = function(p,xi,l,d,g)   xi + (l*exp((qnorm(p) - g)/d))/(1 +
exp((qnorm(p) - g)/d))

f1c <- fitdist(data2,"john",start=list(xi = 0.5 ,l = 50, d = 1, g = 1))

Error in fitdist(data2, "john", start = list(xi = 0.5, l = 50, d = 1,  :
  the function mle failed to estimate the parameters,
                with the error code 100
In addition: Warning message:
In log(((x)/l)/(1 - ((x)/l))) : NaNs produced


Cheers
AG

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