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rglmbroom

Pretty summaries for statistical models

I am looking for a pretty way to see the statistical model summaries in R. In the following example, I want to see cyl_6 or cyl.6 instead of cyl6. How can I do that?

library(dplyr)
library(broom)

mean_mpg <- mean(mtcars$mpg)

# creating a new variable that shows that Miles/(US) gallon is greater than the mean or not

mtcars <-
  mtcars %>%
  mutate(mpg_cat = ifelse(mpg > mean_mpg, 1,0))

mtcars$cyl <- as.factor(mtcars$cyl)

model <-
mtcars %>%
  select (cyl,vs, am, mpg_cat) %>%

  glm(formula = mpg_cat ~ .,
      data = ., family = "binomial")


tidy(model)

enter image description here

Solution

  • I can think of one way to do this but it's pretty clunky: change the contrasts attribute for cyl (and any other factors you want to include) before running the model:

    mtcars$cyl <- as.factor(mtcars$cyl)
cont = contrasts(mtcars$cyl)
colnames(cont) = paste0("_", colnames(cont))
contrasts(mtcars$cyl) = cont

model <-
    mtcars %>%
    select (cyl,vs, am, mpg_cat) %>%

    glm(formula = mpg_cat ~ .,
        data = ., family = "binomial")

tidy(model)

    Output:

    # A tibble: 5 x 5
  term        estimate std.error  statistic p.value
  <chr>          <dbl>     <dbl>      <dbl>   <dbl>
1 (Intercept)   22.9      24034.  0.000953    0.999
2 cyl_6        -22.4      12326. -0.00182     0.999
3 cyl_8        -44.5      23246. -0.00191     0.998
4 vs            -1.59     13641. -0.000117    1.000
5 am             0.201    13641.  0.0000147   1.000

    If you wanted this behaviour by default, I guess you could write a modified version of contr.treatment that sets the column names how you want and then set that as the default with options(contrasts = ...)? I haven't tested if that works.