## 4.13 Convert models to equations

The equatiomatic package (https://github.com/datalorax/equatiomatic) developed by Daniel Anderson et al. provides a convenient and automatic way to show the equations corresponding to models fitted in R. We show a few brief examples below:

fit <- lm(mpg ~ cyl + disp, mtcars)
# show the theoretical model
equatiomatic::extract_eq(fit)

$\operatorname{mpg} = \alpha + \beta_{1}(\operatorname{cyl}) + \beta_{2}(\operatorname{disp}) + \epsilon$

# display the actual coefficients
equatiomatic::extract_eq(fit, use_coefs = TRUE)

$\operatorname{mpg} = 34.66 - 1.59(\operatorname{cyl}) - 0.02(\operatorname{disp}) + \epsilon$

To display the actual math equations, you need the chunk option results = "asis" (see Section 11.11 for the meaning of this option), otherwise the equations will be displayed as normal text output.