# Homework 2
# Copy mtcars dataset into new variable called myCars
myCars <- mtcars
# Step 1 - What is the hp
# Question 1: find highest horsepower
max(myCars$hp)
# Question 2: find the car with highest horsepower
index <- which.max(myCars$hp)
Myrnames <- rownames(myCars[index,])
Myrnames
# Step 2 - Explore mpg
# Question 3: What is the highest mpg?
max(myCars$mpg)
# Question 4: Which car has the highest mpg?

index <- which.max(myCars$mpg)
rnames <- rownames(myCars)
car <- rnames[index]
car

cat("Max mpg and car name:", car, max(myCars$mpg))

# Question 5: Create a sorted dataframe based on mpg
sortedMPG <- myCars[order(-myCars$mpg),]
sortedMPG
# Step 3 - Which car has the best combination of mpg and hp
# Question 6: What logic did you use?
myCars$mpgAndHp <- c(myCars$mpg * myCars$hp)
MyIndex <- which.max(myCars$mpgAndHp)
rownames(myCars[MyIndex,])
#2 lines at once: rownames(myCars[which.max(myCars$mpgAndHp),])

# Question 7: Which car?
rownames(myCars[MyIndex,])

# Step 4 - Which car has the best car combination of mpg and hp, given equal weight?
#create normalized columns of mpg and hp
myCars$scaleMPG <- scale(myCars$mpg)
myCars$scaleHP <- scale(myCars$hp)

myCars$scaledMPGAndHp <- myCars$scaleMPG + myCars$scaleHP
# find the car with best combination
MyIndex <- which.max(myCars$scaledMPGAndHp)
rownames(myCars[MyIndex,])