R

  1. Options
  2. Sourcing
  3. Output
  4. Version check

Options

What How Details
Debug (browse) on error options(error=recover)  
Treat warnings as errors options(warn=2)  
Readable traceback options(error=function() traceback(max.lines=3))  
Disable scientific notation options(scipen=999)  

Sourcing

What How Details
Run R script (source) source('file.R')  
Get sourced file from within script as.character(sys.call(1))[2] Does not work during start-up!
Get sourced directory from within script dirname(as.character(sys.call(1))[2])  

Output

What How Details
Output cat('hello')  
Output object cat(x)  
Generic print print('hello')  
Show message message('msg')  
Show warning warning('warning')  
Show warning right now warning('warning', .immediate=TRUE)  
Trigger and show error stop('error')  
Redirect output to file sink('log.txt') Use sink() to restore
Capture any output as string txt = capture.output({...})  
Suppress automatic printing in interactive mode invisible(x)  
Suppress all output capture.output({...})  
Suppress all output sink('nul:') '/dev/null' on linux?
Suppress messages suppressMessages({...})  
Suppress package messages on load suppressPackageStartupMessages({...})  
Suppress warnings suppressWarnings({...})  

Version check

What How Details
Run code conditional on R version if (compareVersion(paste(version$major, version$minor, sep='.'), '3.6.0') >= 0) {
RNGkind(sample.kind='Rounding') # fix to reproduce RNG of R 3.5.0
}		  

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