Introduction to Data Analysis with R

Using Basic Data Analysis functions on the mtcars dataset

Let’s Start

# Copying mtcars data frame to our new data frame myCars
myCars <- mtcars

Which car has the highest horsepower (hp) ? 

#find and display the car with the highest horsepower index <- which.max(myCars$hp)
# Display the car name along with the rest of the row myCars[index,]
##                mpg cyl disp hp drat  wt  qsec vs am  gear carb ## Maserati Bora  15   8  301 335 3.54 3.57 14.6  0  1    5    8

Maserati Bora has the highest horsepower at 335

Exploring miles per gallon (mpg) of the cars

# find and display the car with the highest mpg
index<-which.max(myCars$mpg)
myCars[index,]
##                 mpg cyl disp hp drat    wt qsec vs am gear carb ## Toyota Corolla 33.9   4 71.1 65 4.22 1.835 19.9  1  1    4    1
# Creating a sorted dataframe, based on mpg
highMPGcars <- myCars[ order(-myCars$mpg),]
head(highMPGcars)
mpg cyl  disp  hp drat    wt  qsec vs am gear carb ## Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Fiat 128       32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1 ## Honda Civic    30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Lotus Europa   30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2 ## Fiat X1-9      27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1 ## Porsche 914-2  26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2

Which car has the “best” combination of mpg and hp?

# Best car combination of mpg and hp, where mpg and hp must be given equal # weight
bestCombo<- myCars$hp / myCars$mpg
myCars[which.max(bestCombo),]
##                mpg cyl disp  hp drat   wt qsec vs am gear carb ## Maserati Bora  15   8  301 335 3.54 3.57 14.6  0  1    5    8

The Maserati Bora hp to mpg is ~ 22hp per gallon