Data frames and tidy data

Data frames and tidy data

Objectives

• Common data file types

• Excel, data setup, and the Data Dictionary

• Getting data into R

• Manipulating variables in the Data Frame

• Practice exercises

Tidy data concept

• Archives data in accessible format

• Data “transparent” to others

• “Tidy Data” credit: Hadley Wickham (lead statistician at Posit)

• Wickham 2014

Tidy data concept

Common data file types

• (c)sv comma separated values + others

• Excel

• Avoid (!) proprietary formats

• Data Dictionary

Untidy data

Tidy data

Tidy dictionary

Tidy csv

Getting data into R

Choices

• from File > Import Data

• readxl::read_excel()

• openxlsx::read.xlsx()

Demonstration

Manipulating variables in the Data Frame

• class()

• names()

• str()

• indexes [ , ]

• attach()

Practice Exercises