Number of significant digits in dplyr summarise

Question

I am having trouble getting the desired number of decimal places from summarise. Here is a simple example:

test2  <- data.frame(c(\"a\",\"a\",\"b\",\"b\")         


        

Answer 1

I think the simplest solution is the following:

test2  <- data.frame(c("a","a","b","b"), c(245,246,247,248))
library(dplyr)
colnames(test2)  <- c("V1","V2")
group_by(test2,V1) %>% summarise(`mean(V2)` = sprintf("%0.1f",mean(V2)))
# A tibble: 2 x 2
  V1    `mean(V2)`
        
1 a     245.5     
2 b     247.5