Is there a function in R to connect tapply with round?-CodePudding

Probably the solution is simple, but I can't find it right now. I like to use tapply in descriptive-statistical analyses. For example:

tapply(dataframe1$Means, dataframe2$gender, function(x) {
  c(
    "mean" = mean(x, na.rm = TRUE),
    "sd" = sd(x, na.rm = TRUE),
    "med" = median(x, na.rm = TRUE),
    "min" = min(x, na.rm = TRUE),
    "max" = max(x, na.rm = TRUE)
  )
})

Now I would like to have the results rounded directly to two places, but without writing them to another or new object.

Thanks for tips

CodePudding user response：

Is it what you are looking for? I added round(c(...), digits = 2) around the group of summary functions (mean, sd, etc.) so the function does the rounding inside tapply without creating a new object.

Edit: better version without repeating the round() function.

tapply(iris$Sepal.Length, iris$Species, 
       function(x){round(c("mean" = mean(x, na.rm = TRUE),
                     "sd" = sd(x, na.rm = TRUE), 
                     "med" = median(x, na.rm = TRUE), 
                     "min" = min(x, na.rm = TRUE), 
                     "max"= max(x, na.rm = TRUE)), digits = 2)})
#> $setosa
#> mean   sd  med  min  max 
#> 5.01 0.35 5.00 4.30 5.80 
#> 
#> $versicolor
#> mean   sd  med  min  max 
#> 5.94 0.52 5.90 4.90 7.00 
#> 
#> $virginica
#> mean   sd  med  min  max 
#> 6.59 0.64 6.50 4.90 7.90

^{Created on 2022-05-10 by the reprex package (v2.0.1)}

CodePudding user response：

You can wrap your tapply with another lapply with round.

lapply(
  tapply(iris$Sepal.Length, iris$Species, function(x) {
    c("mean" = mean(x, na.rm = TRUE),
      "sd" = sd(x, na.rm = TRUE), 
      "med" = median(x, na.rm = TRUE), 
      "min" = min(x, na.rm = TRUE), 
      "max" = max(x, na.rm = TRUE))}), 
  round, digits = 2
)

$setosa
mean   sd  med  min  max 
5.01 0.35 5.00 4.30 5.80 

$versicolor
mean   sd  med  min  max 
5.94 0.52 5.90 4.90 7.00 

$virginica
mean   sd  med  min  max 
6.59 0.64 6.50 4.90 7.90