There are many ways to store data. Here are some of the most common ways to read in data using the readr
package.
# Load the readr package
library(readr)
read_delim
The read_delim()
function will read in data from many different file types. The code below reads in data from a file saved on the web. The web address is saved in a variable called web.url
.
The col_names = TRUE
indicates that the first row of the file contains the variable names.
The delim=","
argument indicates that the file contains variable names and data values that are separated, delimited, by commas.
Thetrim_ws=TRUE
argument removes all spaces from the variable name.
# data url
web.url = "http://homepages.gac.edu/~anienow2/MCS_142/R/example.csv"
# reads in the data and saves it to a variable
the.data <- read_delim(file = web.url, col_names = TRUE, delim = ",", trim_ws= TRUE)
##
## ── Column specification ───────────────────────────────────────────────────────────────────────────
## cols(
## Name = col_character(),
## Height = col_double(),
## Eye.Color = col_character(),
## Hand = col_character(),
## Gender = col_character()
## )
Look at the output above. The read_delim()
function guesses at the variable type to use for each column. In this case it guessed correctly that Height
was a quantitative variable, but guessed incorrectly about Eye.Color
, Hand
, and Gender
. See the Modifying Data tutorial to fix this.
# Look at the data
the.data
## # A tibble: 5 x 5
## Name Height Eye.Color Hand Gender
## <chr> <dbl> <chr> <chr> <chr>
## 1 Shelly 55 Blue Right F
## 2 Alvin 60 Green Left M
## 3 Simon 67 Blue Right M
## 4 Theo 72 Green Right M
## 5 Nicki 54 Brown Right F
read_csv
The read_csv()
function is a special case of the read_delim()
function. The .csv
extension is short for comma separated values. This function assumes the file is delimited with commas. The code below uses the read_csv()
function instead of the read_delim()
function to read in the file stored at web.url
.
# data url
web.url = "http://homepages.gac.edu/~anienow2/MCS_142/R/example.csv"
# reads in the data and saves it to a variable
the.data <- read_csv(file = web.url, col_names = TRUE, trim_ws= TRUE)
##
## ── Column specification ───────────────────────────────────────────────────────────────────────────
## cols(
## Name = col_character(),
## Height = col_double(),
## Eye.Color = col_character(),
## Hand = col_character(),
## Gender = col_character()
## )
The read_excel()
function in the readxl
package will read in data from an excel spreadsheet (.xlsx). The data from this function is stored as a tibble. See the help page ?readxl::read_excel
for a more detailed listing of arguments and usage for this function and package. Below is example code for a simple use case.
# Loads the library
library(readxl)
# reads in the data from a file
the.data <- read_excel(path="./example.xlsx", sheet=1)
The code below will allow you to read data from a file that is stored locally on your computer. The ./
in front of the file name indicates that the file is located in the current directory. You may need to move the file or change the working directory to get this to work.
# reads in the data from a file
the.data <- read_csv(file="./example.csv", col_names = TRUE, trim_ws=TRUE)
Mathematicss, Computer Science, and Statistics Department Gustavus Adolphus College