Working with functions

Benchmark code

system.time(mean(1:10^7))

##    user  system elapsed 
##   0.044   0.011   0.056

Inform users with a message

message('Hello world')

## Hello world

Abort execution and return error message

stop('Something went wrong')
> Error: Something went wrong

Do not abort code if error is returned

try(log("you can't log a string"))

Suppress messages

# When using a function
suppressMessages(expr)

# When loading libraries
suppressPackageStartupMessages( library(ggplot2) )