CODEWITHSUNDEEP
rlmbroom
user4687531
user4687531

Reputation: 1111

Displaying a broom::tidy tibble as a printed summary table

I have what may seem like a strange question (but details of why I'm asking will become clear soon).

Consider fitting a linear model in R, as follows:

lm_fit <- lm(mpg ~ cyl+disp, data = mtcars).

Now suppose we produce a tidy tibble (named out_summ) of the summary of our fit using the amazing broom package as follows:

out_summ <- broom::tidy(lm_fit)
out_summ
#> # A tibble: 3 x 5
#>   term        estimate std.error statistic  p.value
#>   <chr>          <dbl>     <dbl>     <dbl>    <dbl>
#> 1 (Intercept)  34.7       2.55       13.6  4.02e-14
#> 2 cyl          -1.59      0.712      -2.23 3.37e- 2
#> 3 disp         -0.0206    0.0103     -2.01 5.42e- 2

Created on 2021-02-02 by the reprex package (v0.3.0)

Now consider just printing the summary of the lm_fit object to the console as follows:

summary(lm_fit)
#> 
#> Call:
#> lm(formula = mpg ~ cyl + disp, data = mtcars)
#> 
#> Residuals:
#>     Min      1Q  Median      3Q     Max 
#> -4.4213 -2.1722 -0.6362  1.1899  7.0516 
#> 
#> Coefficients:
#>             Estimate Std. Error t value Pr(>|t|)    
#> (Intercept) 34.66099    2.54700  13.609 4.02e-14 ***
#> cyl         -1.58728    0.71184  -2.230   0.0337 *  
#> disp        -0.02058    0.01026  -2.007   0.0542 .  
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#> 
#> Residual standard error: 3.055 on 29 degrees of freedom
#> Multiple R-squared:  0.7596, Adjusted R-squared:  0.743 
#> F-statistic: 45.81 on 2 and 29 DF,  p-value: 1.058e-09

Created on 2021-02-02 by the reprex package (v0.3.0)

Now, my question is given the lm_fit object and the tidy out_summ tibble as inputs, is it possible write a function to easily reproduce the printed summary(lm_fit) table shown above?

I looked at the getAnywhere(print.summary.lm) for the lm summary function and it is quite complicated. In the sense that it sources individual columns and manually adjusts spacing using cat() to pretty print. As such given the tidy tibbles, can this be easily reverse engineered?

Motivation: I'm developing a statistical modeling object similar to lm, however we are using tidy tibble formats from the start. We would still like to add a summary method to our object. This would take our tidy tibble format and print it out using the format of the summary(lm_fit) output style above. That is, we don't want to just print the tibble, without first making it look like the classical summary table format.

Any help on achieving this, with hopefully minimal code (given the tidy input), would be appreciated.

Upvotes: 1

Views: 1122

Answers (1)

jared_mamrot
jared_mamrot

Reputation: 26700

Not sure how to fill in the rest of the summary table without using the lm_fit object (or equivalent), but maybe these 'first steps' will help.

library(tidyverse)

lm_fit <- lm(mpg ~ cyl+disp, data = mtcars)

summarise_lm_like_object <- function(lm_fit){
  out_summ <- broom::tidy(lm_fit) %>%
    mutate(sig = ifelse(p.value <= 0.001, "***",
                        ifelse(p.value <= 0.01, "**",
                               ifelse(p.value <= 0.05, "*", ".")))) %>% 
    rename("Estimate" = estimate,
           "Std. Error" = std.error,
           "t value" = statistic,
           "Pr(>|t|)" = p.value,
           "Significance" = sig)
  
  print.data.frame(out_summ, row.names = FALSE)
  cat("---\n")
  cat("Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1")
}

summarise_lm_like_object(lm_fit)
#>         term    Estimate Std. Error   t value     Pr(>|t|) Significance
#>  (Intercept) 34.66099474 2.54700388 13.608536 4.022869e-14          ***
#>          cyl -1.58727681 0.71184427 -2.229809 3.366495e-02            *
#>         disp -0.02058363 0.01025748 -2.006696 5.418572e-02            .
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Created on 2021-02-03 by the reprex package (v1.0.0)

Upvotes: 1

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