script_reglogis.R

library(aplore3)

data(chdage)
head(chdage)

# ajuste 1
mod1 <- glm(chd ~ age, family = binomial(), data = chdage)
summary(mod1)

#
exp(-5.309 + 0.111*50)/(1 + exp(-5.309 + 0.111*50))

#
pix <- function(x) {
  exp(-5.309 + 0.111*x)/(1 + exp(-5.309 + 0.111*x))
}
plot(function(x) pix(x), 0, 80, ylim = c(0, 1),
     ylab = expression(paste(pi, "(AGE)")), xlab = "AGE")
abline(h = 1, lty = 2)

# com variavel categorica
mod2 <- glm(chd ~ agegrp, family = binomial(), 
            data = chdage)
summary(mod2)