CODEWITHSUNDEEP
rtidyverse
Eric Green
Eric Green

Reputation: 7735

creating summary tables with tidyverse

Q1. Is there a more direct (but still tidyverse) way to create a summary table like this?

enter image description here

library(tidyverse)
library(knitr)
library(kableExtra)
df <- data.frame(group=c(1, 1, 1, 1, 0, 0, 0, 0),
                 v1=c(1, 2, 3, 4, 5, 6, 1, 2),
                 v2=c(4, 3, 2, 5, 3, 5, 3, 8),
                 v3=c(0, 1, 0, 1, 1, 0, 1, 1))

df %>%
  group_by(group) %>%
  summarise(v1=paste0(round(mean(v1), 2),
                      " (",
                      round(sd(v1), 2),
                      ")"),
            v2=paste0(round(mean(v2), 2),
                      " (",
                      round(sd(v2), 2),
                      ")"),
            v3=round(mean(v3)*100, 1)
  ) %>%
  dplyr::select(-group) %>%
  t() %>%
  `rownames<-` (c("v1 mean (SD)",
                  "v2 mean (SD)",
                   "Percent v3")) %>%
  kable("html",
        col.names=c("Group 0", "Group 1")) %>%
  kable_styling()

Q2. Related to this, is there a way to combine two levels of summarise (e.g., no grouping + grouping) without repeating the summarise code?

enter image description here

all <- 
df %>%
  summarise(v1=paste0(round(mean(v1), 2),
                      " (",
                      round(sd(v1), 2),
                      ")"),
            v2=paste0(round(mean(v2), 2),
                      " (",
                      round(sd(v2), 2),
                      ")"),
            v3=round(mean(v3)*100, 1)
  ) %>%
  t() %>%
  `rownames<-` (c("v1 mean (SD)",
                  "v2 mean (SD)",
                   "Percent v3")) 

groups <- 
  df %>%
  group_by(group) %>%
  summarise(v1=paste0(round(mean(v1), 2),
                      " (",
                      round(sd(v1), 2),
                      ")"),
            v2=paste0(round(mean(v2), 2),
                      " (",
                      round(sd(v2), 2),
                      ")"),
            v3=round(mean(v3)*100, 1)
  ) %>%
  dplyr::select(-group) %>%
  t() %>%
  `rownames<-` (c("v1 mean (SD)",
                  "v2 mean (SD)",
                  "Percent v3")) 

all %>%
  cbind(groups) %>%
  kable("html",
        col.names=c("All", "Group 0", "Group 1")) %>%
  kable_styling()

Upvotes: 1

Views: 2828

Answers (2)

Hao
Hao

Reputation: 7856

This is the minimum I can think of.

cat_var <- "v3"

df_cal <- function(x, var) {
  if (var[1] %in% cat_var) return(as.character(round(mean(x), 1)))
  paste0(mean(x), " (", round(sd(x), 2), ")")
}

df_tall <- df %>% gather(var, x, v1:v3) %>% group_by(var)

all <- df_tall %>% summarise(stat = df_cal(x, var)) %>% mutate(group = -1)
groups <- df_tall %>% group_by(group, var) %>% summarise(stat = df_cal(x, var)) 

bind_rows(all, groups) %>%
  ungroup() %>%
  mutate(var = factor(var, labels = c(
    "v1 mean (SD)", "v2 mean (SD)", "Precent v3"
  ))) %>%
  spread(group, stat) %>%
  kable("html", col.names = c(" ", "All", "Group 0", "Group 1")) %>%
  kable_styling()

Upvotes: 1

Daniel Sch&#252;tte
Daniel Sch&#252;tte

Reputation: 618

One solution (especially if you want to expand the number of columns v1, v2, ... in the future) to make your code a bit more concise might be, to put paste0(round(mean(v1), 2)," (", round(sd(v1), 2), ")") into a function: paste_mean_and_sd = function(df_col){paste0(round(mean(df_col), 2)," (", round(sd(df_col), 2), ")")}.

That would shorten your "pipeline" and make it more easily readable:

... %>% summarise(v1 = paste_mean_and_sd(v1), v2 = paste_mean_and_sd(v2), v3=round(mean(v3)*100, 1)) %>% ...

Upvotes: 1

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