Identify the problem and make a plan

Overview

Questions

• What do I do when I encounter an error?
• What do I do when my code outputs something I don’t expect?
• Why do errors and warnings appear in R?
• Which areas of code are responsible for errors?
• How can I fix my code? What other options exist if I can’t fix it?

Objectives

After completing this episode, participants should be able to…

• decode/describe what an error message is trying to communicate
• Identify specific lines and/or functions generating the error message
• Lookup function syntax, use, and examples using R Documentation (?help calls)
• Describe the general category of error message (e.g. syntax error, semantic errors, package-specific errors, etc.)
• Describe the output of code you are seeking
• Identify and quickly fix commonly-encountered R errors
• Identify which problems are better suited for asking for further help, including online help and reprex

Predict the output from a base R function call

Which of the following results when running the following line of code:

R

length(5, 6, 7)

1. 3
2. Error in length(5, 6, 7) : 3 arguments passed to ‘length’ which requires 1
3. NULL
4. 1, 1, 1

Solution Title

2. Error in length(5, 6, 7) : 3 arguments passed to ‘length’ which requires 1