Appendix C — Definitions
Argument- one of possibly several expressions that are passed to a function
Assignment - Giving a value to a variable.
<-is known as the “assignment operator”.Comment: Text written in a script that is not treated as code to be run, but rather as text that describes what the code is doing. These are usually short notes, beginning with a #
Console - Place you run your code. It prints all the inputs and outputs - but then it’s gone!
Comprehensive R Archive Network (CRAN) - A public repository of R packages
Data frame - A two-dimensional data structure for storing tabular data in memory. Rows represent records and columns represent variables.
Environment - A collection of functions, objects, and variables that are available for you to work with.
Function - A code block which gathers a sequence of operations into a whole, preserving it for ongoing use by defining a set of tasks that takes zero or more required and optional arguments as inputs and returns expected outputs (return values), if any. Functions enable repeating these defined tasks with one command, known as a function call.
GUI - “Graphical User Interface” - anything you can point-and-click to get what you want. This is in contrast to the “command line” where you have to write out what you want.
Script - Text file with code you want to run
Project - Set of scripts, data, and outputs that are associated with a working directory and are related to each other using an .Proj file.
Package - A collection of code, data, and documentation that can be distributed and re-used. Also referred to in some languages as a library or module.
Pipe operator: The
%>%used to make the output of one function the input of the next. Piping works particularly well with Tidyverse packages.Object - A data set, a variable, plot, or more formally, almost everything in R. If it has a mode, it is an object. Includes data frames, vectors, matrices, arrays, lists and functions.
Tidyverse - A collection of R packages for operating on tabular data in consistent ways.
Vector - A list of items of the same type (e.g., a list of numbers or words).
Working directory - The folder that contains all the scripts and data you are working with.