texmex (version 2.4.9)

migpdCoefs: Change values of parameters in a migpd object

Description

Change the values of parameters in a migpd object. You might want to do this after modelling marginal distributions as functions of covariates.

Usage

migpdCoefs(object, which, coefs)

Value

A migpd object. See the help for migpd.

Arguments

object

An object of class migpd.

which

Which models in the migpd object you want to change.

coefs

The coefficients that you want to change to. If which has length 1, coefs can be a vector of parameters. Otherwise, it should be a list of vectors, and the list should have the same length as which

Author

Harry Southworth

See Also

migpd

Examples

library(MASS)
liver <- liver
liver$ndose <- as.numeric(liver$dose)
d <- data.frame(alt = resid(rlm(log(ALT.M) ~ log(ALT.B) + ndose, data=liver)),
                ast = resid(rlm(log(AST.M) ~ log(AST.B) + ndose, data=liver)),
                alp = resid(rlm(log(ALP.M) ~ log(ALP.B) + ndose, data=liver)),
                tbl = resid(rlm(log(TBL.M) ~ log(TBL.B) + ndose, data=liver)))

Dgpds <- migpd(d[liver$dose == "D", 1:4], mqu=.7)

d$ndose <- liver$ndose
galt <- evm("alt", data=d, qu=.7, xi = ~ ndose)
gast <- evm("ast", data=d, qu=.7, xi = ~ ndose)
galp <- evm("alp", data=d, qu=.7, xi = ~ ndose)

altco <- predict(galt,type="lp",newdata=data.frame(ndose=4))$obj$link[1:2]
astco <- predict(gast,type="lp",newdata=data.frame(ndose=4))$obj$link[1:2]
alpco <- predict(galp,type="lp",newdata=data.frame(ndose=4))$obj$link[1:2]

Dgpd <- migpdCoefs(Dgpds, which=c("alt", "ast", "alp"),
                   coefs=list(altco, astco, alpco))

summary(Dgpd)
summary(Dgpds)