R/der2phiBY3.R

In musto101/wilcox_R: What the package does (short line)

der2phiBY3 <-
function(s,y,c3)
{
  s=as.double(s)
  Fs= exp(-(log(1+exp(-abs(s)))+abs(s)*(s<0)))
  ds=Fs*(1-Fs)
  dev=log(1+exp(-abs(s)))+abs(s)*((y-0.5)*s<0)
  Gprim1=log(1+exp(-abs(s)))+abs(s)*(s<0)
  Gprim2=log(1+exp(-abs(s)))+abs(s)*(s>0)
  der2=(derpsiBY3(dev,c3)*(Fs-y)^2)+(ds*psiBY3(dev,c3))
  der2=der2+(ds*(1-2*Fs)*(psiBY3(Gprim1,c3)-psiBY3(Gprim2,c3)))
  der2=der2-(ds*((derpsiBY3(Gprim1,c3)*(1-Fs))+(derpsiBY3(Gprim2,c3)*Fs)))
  der2
}