Model functions

inv() function

inv(v[r])
forms the reciprocal of v + r. This may also be used to transform the response variable.

log() function

log(v[r]
forms the natural log of v + r. This may also be used to transform the response variable.

pow() function

pow(v,p[,r]
raises v + r.to power p. This may also be used to transform the response variable. This is equivalent to natural log transformation if p is zero.

sqrt() function

sqrt(v[r])
forms the square root of v + r. This may also be used to transform the response variable.