source("http://192.38.117.59/~linearpredictors/datafiles/readFever.R")

par(mfrow = c(1,2))

## Linear model with alcohol as explanatory variable
model <- glm(death ~ alco, 
             family = binomial,
             data = fever)

## Influence of observations on the estimated coefficients

modeldata <- model$model ## the data.frame actually used in the model
influences <- dfbetas(model)

plot(modeldata$alco, influences[,2],
     pch = ifelse(modeldata$death==1,3,1),
     xlab = "Drinks per week",
     ylab = expression(dev(b)[i]),
     ylim = c(-0.2,0.8)
     )

plot(modeldata$alco, influences[,1],
     pch = ifelse(modeldata$death==1,3,1),
     xlab = "Drinks per week",
     ylab = expression(dev(a)[i]),
     ylim = c(-0.3,0.1)
     )