10: Introduction to Importing Data in R

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What function do you use to import a .csv file? What are its major arguments?

read.csv(“path to file“)

What function builds a path to a file in a way this is independent of platform? (platform being linux, mac, windows, etc.) How does this function work?

file.path()

For this function you enter a series of strings representing the destinations along a path and the endpoint of the path.

What function do you use to import data in a table format? What are the basic arguments for this function, and what do they mean?

read.table()

… : The file name

header: Whether the first row of the file contains the variable names

sep: What separates the values in the file

What function do you use to import non-csv delimited files?

read.delim()

What is the structure of the read import functions?

They all call read.table, but have different default args

What is the readr function to import a csv file? What are the general outputs of readr functions?

read_csv()

readr generally outputs tibbles

What is the readr function to import a delimited file?

read_tsv()

What is the structure of the readr import functions? What are the required args for the main function?

They all call read_delim, but have different default args

The required args are file and delim

What type of function can help you set the type of a column?

A collector function

When do you want to use the data.table package? What is the main function of this package, and what is an advantage of this function that wouldn’t be in the answer of the previous question?

If you want to import and munge large data files

fread() is the main function, and it is conveniant because it can name columns and recognize delim operators without the user

What package allows you to wrangle excel file? What function allows you to see the sheets in the excel file? What function allows you to import an excel sheet?

readxl

read_excel()

excel_sheets()

For the function that imports excel files, what value for what argument allows you to get rid of a column?

col_type = “blank”

What package allows you to better manipulate excel files from within R? What issue does this package commonly run into during installation?

XLConnect

This package runs in conjunction with Java which can cause issues

Using the excel manipulation package, what function allows you to import a workbook? What function allows you to import a sheet? What function allows you to get the name of the sheets in the workbook?

loadWorkbook()

readWorksheet()

getSheets()

What function creates a blank manipulatable sheet? What function allows you to populate this sheet?

createSheet()

writeWorksheet()

What function adds a sheet to an ACTUAL excel file? What is a feature of this function that is important to remember?

saveWorkbook()

This function can save a sheet to a new workbook / file that the function itself creates

What function changes the name of a sheet?

renameSheet()

What function gets rid of a sheet from a workbook?

removeSheet()

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