| dDeta {mgcv} | R Documentation | 
INTERNAL function. Distribution families provide derivatives of the deviance and link w.r.t. mu = inv_link(eta).
This routine converts these to the required derivatives of the deviance w.r.t. eta, the linear predictor.
dDeta(y, mu, wt, theta, fam, deriv = 0)
y | 
 vector of observations.  | 
mu | 
 if   | 
wt | 
 vector of weights.  | 
theta | 
 vector of family parameters that are not regression coefficients (e.g. scale parameters).  | 
fam | 
 the family object.  | 
deriv | 
 the order of derivative of the smoothing parameter score required.  | 
A list of derivatives.
Simon N. Wood <simon.wood@r-project.org>.