library(MASS) summary(menarche) plot(menarche) plot(menarche$Age, menarche$Menarche/menarche$Total) menarche$SF<- cbind(menarche$Menarche,menarche$Total-menarche$Menarche) mn<- glm(SF~Age, data=menarche, family=binomial(link="logit")) summary(mn) anova(mn) lines(menarche$Age, fitted(mn), lty=2, col=4) mnp<- glm(SF~Age, data=menarche, family=binomial(link="probit")) summary(mnp) anova(mnp) mnq<- glm(SF~Age, data=menarche, family=quasibinomial(link="logit")) summary(mnq) mnpq<- glm(SF~Age, data=menarche, family=quasibinomial(link=probit)) summary(mnpq) mnfull<- glm(SF~as.factor(Age), data=menarche, family=binomial(link="logit")) summary(mnfull) anova(mn,mnfull) # the test against the full model is not significant mn2<- update(mn, .~.+I(Age^2)) summary(mn2) mn3<- update(mn2, .~.+I(Age^3)) summary(mn3) lines(menarche$Age, fitted(mn3), lty=5, col=4) # some indication of non-linearity