FAQ

How to deal with some issues that may pop up

Permission to install packages locally

Mac users may need to alter their security preferences to allow apps authored by non-Apple developers to install. If you notice an error, try to change your system preferences.

Common Mistakes

  • Spelling mistakes
    • I swear, 80 percent of my mistakes come from typos
  • Using the wrong case
    • help(), Help(), and HELP() are three different functions (and only the first one will work)
  • Forgetting to use quotation marks when they are needed
    • install.packages(“gclus”) will work, while install.packages(gclus) will generate an error.
  • Forgetting to include the parentheses in a function call
    • help() rather than help. Even if there are no options, you still need the().
  • Using the \ in a path name on Windows
    • R sees the backlash character as an escape character.
    • setwd("c:\mydata") will generate an error. Use setwd("c:/mydata") or setwd("c:\\mydata") instead
  • Using a function from a package that is not loaded
    • The function str_trim() is contained in the stringr package.
    • If you try to use it before loading the package, you will get an error

Other possible issues

  • Package conflicts
    • Sometimes, packages depend on other packages to work correctly
    • If it says a package is missing, install it and then install the one that caused the error
    • To specify a specific package for a function, precede the code with nameofpackage::
      • For example, filter() will turn into dplyr::filter()
  • File cannot be found
    • Check getwd() is the file you’re trying to access in that directory that R thinks it should look?
      • If not, use setwd() to point to the correct directory.
    • Is the file name spelled correctly?
      • Run ls() to get a list of the files in the working directory and see if that file matches what’s listed.
      • Sometimes it’s as simple as a capital letter when it shouldn’t.
    • R working directory doesn’t work ideally with unzipped folders
      • Make sure if you extract a zip, you move the folder to your computer and not just a temporary folder
  • Objects, including column names, need to be one word
    • Space won’t be interpreted correctly unless in the context of strings, so it must be surrounded by quotation marks
    • To deal with columns that have spaces, you use the backtick ` next to the 1 button on your keyboard. so referencing column name on a dataframe called temp will be temp$`column name`
  • Warnings
    • Warning message: package 'whatever' was built under R version 3.x.x
      • Make sure you have the latest version of R and RStudio installed
    • Sometimes unfix-able, sometimes worth fixing
      • As long as it doesn’t mess up your data (for example, sometimes the warning that some items were replaces with NA is okay, and sometimes it’s horrible)

What’s with the weird phrase in the Console when I start R?

  • Every version of release for R references a different Peanuts comic strip or film.
    • You Stupid Darkness
    • Kite Eating Tree

Other ways to find solutions

  • Search for your question on StackOverflow or on Google
    • I’ve found answers to so many of my questions thanks to others who have encountered the same problem as me
  • If you can’t find a solution after Googling it, shoot it out to the #rstats community on Twitter
    • You’ll probably get a response that might solve your problem and maybe a GIF reaction for the heck of it
  • If it’s a problem related to a package, track down the GitHub repo for it and submit a question to the contributors
    • Sometimes your issue might be something that will help lead to a fix that improves the experience for all other users
    • I’ve found that R package creators are very responsive on GitHub and even Twitter with questions

© Copyright 2018, Andrew Ba Tran

© Copyright 2018, Andrew Tran