Just like the title, I want to use multiple independent variables in my model.
There is an easy example:
If I want to see the relationship between mpg and disp, I could use this:
mtcars %>% ggplot(aes(y = mpg, x = disp)) +
geom_point() +
geom_smooth(formula = y ~ x)
Then I want to see the relationship between mpg and disp adjusted hp, I write the below code occurring an error:
mtcars %>% ggplot(aes(y = mpg, x = disp)) +
geom_point() +
geom_smooth(formula = y ~ x + hp)
# Computation failed in `stat_smooth()`:
# object 'hp' not found
Maybe I didn't mapping hp in ggplot(aes()), and I tried this but the same error occurring:
mtcars %>% ggplot(aes(y = mpg, x = disp, z = hp)) +
geom_point() +
geom_smooth(formula = y ~ x + z)
Any help will be highly appreciated!

