How do I format tibbles?

Question

I'd like to make a table that looks like this

I have tibbles with each of the data points, but they're not combined.

library('dplyr')
library('ISLR')

data(Hitters)

Hitters <- na.omit(Hitters)

Q <- Hitters %>% group_by(League) %>% 
  dplyr::summarize(count = n(), avg_wage = sum(Salary)/n())

A <- Hitters %>% group_by(Division) %>% 
  dplyr::summarize(count = n(), avg_wage = sum(Salary)/n())

Z <- Hitters %>% group_by(NewLeague) %>% 
  dplyr::summarize(count = n(), avg_wage = sum(Salary)/n())

My goal is to stack the tibbles above each other in one output with shared "count" and "avg_wage" columns. I tried bind_rows() and ftable(), without success.

Answer 1

The problem is that you can't combine rows with different column names so it ends up giving you a confusing dataframe. We can instead use gather() to create two new columns and get the proper table.

library(tidyverse)
library(ISLR)

data(Hitters)

Hitters <- na.omit(Hitters)

Q <- Hitters %>% group_by(League) %>% 
  dplyr::summarize(count = n(), avg_wage = sum(Salary)/n())

A <- Hitters %>% group_by(Division) %>% 
  dplyr::summarize(count = n(), avg_wage = sum(Salary)/n())

Z <- Hitters %>% group_by(NewLeague) %>% 
  dplyr::summarize(count = n(), avg_wage = sum(Salary)/n())

list(Q,A,Z) %>% 
  map_df(bind_rows) %>% 
  gather("league_type", "league_id", c(1, 4, 5)) %>% 
  filter(!is.na(league_id))
#> Warning: attributes are not identical across measure variables;
#> they will be dropped
#> # A tibble: 6 x 4
#>   count avg_wage league_type league_id
#>   <int>    <dbl> <chr>       <chr>    
#> 1   139     542. League      A        
#> 2   124     529. League      N        
#> 3   129     624. Division    E        
#> 4   134     451. Division    W        
#> 5   141     537. NewLeague   A        
#> 6   122     535. NewLeague   N

^{Created on 2019-01-21 by the reprex package (v0.2.1)}

You can use spread() to get it back to wide format, although I would advise against that. The long version will probably be easier to work with.