Unexpected results when using `aggregate()` with custom functions in R
Quick question that's been bugging me - I've been working on this all day and I'm relatively new to this, so bear with me. I'm trying to summarize a dataset with a custom function using `aggregate()`, but the results are not what I expect. I'm working with R version 4.1.0 and I have the following data frame: ```r set.seed(123) data <- data.frame( group = rep(letters[1:3], each = 4), value = rnorm(12) ) ``` I want to calculate the range of values for each group. Here’s the custom function I wrote: ```r range_func <- function(x) { return(max(x) - min(x)) } ``` I tried to use `aggregate()` like this: ```r result <- aggregate(value ~ group, data, range_func) ``` However, I’m getting a warning message: ``` In aggregate.data.frame(value ~ group, data, range_func) : longer object length is not a multiple of shorter object length ``` The output of `result` shows strange values that don’t align with the expected ranges. I suspect it might be due to how `aggregate()` handles the output of my custom function, but I'm not sure how to fix this. What could be causing this scenario and how can I correctly use my custom function with `aggregate()`? For context: I'm using R on macOS. Any help would be greatly appreciated! My development environment is Linux. Is there a better approach? For context: I'm using R on Debian. The project is a microservice built with R.