Question

If I do

data(mtcars)
m1 <- lm(mpg ~ cyl, data= mtcars, x= TRUE, y= TRUE)

then I can extract the p-value for the slope using summary(m1)$coefficients[2, 4].

But if I do

library(rms)
data(mtcars)
m2 <- ols(mpg ~ cyl, data= mtcars, x= TRUE, y= TRUE)

what do I need to do to extract the p-value for the slope?

Answer 1

You can use the corresponding extractor function, but you need to call summary.lm:

> coef(summary.lm(m2))
          Estimate Std. Error   t value     Pr(>|t|)
Intercept 37.88458  2.0738436 18.267808 8.369155e-18
cyl       -2.87579  0.3224089 -8.919699 6.112687e-10