## Data
datadir <- here::here("materialer", "logistisk", "data")
dat_navn <- file.path(datadir, "blodtryk.xlsx")
dat <- readxl::read_xlsx(dat_navn)
dat <- head(dat, n = 200)
names(dat) <- c("x", "y")
fit <- glm(y~x, family = binomial(), data = dat)
a_mle <- coef(fit)[2]
b_mle <- coef(fit)[1]
p <- function(x,a,b){exp(a*x + b)/(1+exp(a*x+ b))}
library(ggplot2)
library(dplyr)
Attaching package: 'dplyr'
The following objects are masked from 'package:stats':
filter, lag
The following objects are masked from 'package:base':
intersect, setdiff, setequal, union
p_dat <- tibble(x = seq(50, 300, by = .2),
p = p(x, a_mle, b_mle))
dat |>
ggplot(aes(x = x)) +
geom_point(aes(y=y), col = "blue", size = 2, alpha = .5) +
geom_line(data = p_dat, aes(y = p)) +
labs(x = "", y = "") +
theme_grey()
