R comes with a number of example data sets. You can view these data sets in RStudio by typing ‘data()’.

summary(mtcars) # R has automatically loaded the mtcars data frame for us
##       mpg            cyl            disp             hp       
##  Min.   :10.4   Min.   :4.00   Min.   : 71.1   Min.   : 52.0  
##  1st Qu.:15.4   1st Qu.:4.00   1st Qu.:120.8   1st Qu.: 96.5  
##  Median :19.2   Median :6.00   Median :196.3   Median :123.0  
##  Mean   :20.1   Mean   :6.19   Mean   :230.7   Mean   :146.7  
##  3rd Qu.:22.8   3rd Qu.:8.00   3rd Qu.:326.0   3rd Qu.:180.0  
##  Max.   :33.9   Max.   :8.00   Max.   :472.0   Max.   :335.0  
##       drat            wt            qsec            vs       
##  Min.   :2.76   Min.   :1.51   Min.   :14.5   Min.   :0.000  
##  1st Qu.:3.08   1st Qu.:2.58   1st Qu.:16.9   1st Qu.:0.000  
##  Median :3.69   Median :3.33   Median :17.7   Median :0.000  
##  Mean   :3.60   Mean   :3.22   Mean   :17.8   Mean   :0.438  
##  3rd Qu.:3.92   3rd Qu.:3.61   3rd Qu.:18.9   3rd Qu.:1.000  
##  Max.   :4.93   Max.   :5.42   Max.   :22.9   Max.   :1.000  
##        am             gear           carb     
##  Min.   :0.000   Min.   :3.00   Min.   :1.00  
##  1st Qu.:0.000   1st Qu.:3.00   1st Qu.:2.00  
##  Median :0.000   Median :4.00   Median :2.00  
##  Mean   :0.406   Mean   :3.69   Mean   :2.81  
##  3rd Qu.:1.000   3rd Qu.:4.00   3rd Qu.:4.00  
##  Max.   :1.000   Max.   :5.00   Max.   :8.00



If you want to analyze other data in R there are several options for reading your data into R-Studio. Among the most common are…

From a .csv file:

# use the read.csv commmand 
cars <- read.csv('filepath/filename.csv', row.names=1) 
# row.names tells R that the first row of our data contains variable names



From a Stata data file:

# use the read.dta command that is part of the foreign package 
# if you have not already installed the foreign package you can type install.packages("foreign") to install it

library(foreign)
mydata <- read.dta("filepath/filename.dta")



From an Excel data file:

# use the read.xlsx command that is part of the xlsx package 
# if you have not already installed the xlsx package you can type install.packages("xlsx") to install it 
# alternatively you can save your file in .csv format in Excel

library(xlsx)
mydata <- read.xlsx("filepath/filename.xlsx", 2) # the 2 tells R to read in the second page in the Excel workbook