Question

R Studio Coding Exercise Problem-Set Questions 1-6

# 1) Create the following vector in 1 line of code without using the c() function:

# [i] 4 12 20 4 12 20 4 12

# 2) Create a vector of 25 random heights between 54 and 78 inches. Cycle through the vector using a For loop and create a new vector that places each height into a category. People less than 5 feet should be categorized as short, those taller than 6 feet should be categorized as tall, and everyone else should be categorized as average.

# Load the dataset called diamonds which is housed in the ggplot2 package. To do so execute the following steps.
If you have not done so previously, install ggplot 2: install.packages(ggplot)
Load the package: library(ggplot2)
Load the data: data("diamonds")
Diamonds is stored as something called a tibble. Coerce diamonds into a data frame using this code: diamonds<-as.data.frame(diamonds)

# 3) Write code to create a new data frame that is composed of just the diamonds that are Ideal cut.

# 4) Write code to calculate the number of diamonds in the data set

# 5) Write code to calculate the median price of Premium cut, E color diamonds

# 6) Write code to create a histogram showing the distribution of prices of diamonds that are greater than 2 carats.

Answer 1

Refer the screenshots for better understanding

Ans 1: rep(seq(4,20,by = 8), times = 3, length.out = 8)

Ans 2: for random number generation:

           > x <- runif(25, min = 54, max = 78)

Vector "new" consists the required sections:

           > new <- c()

           > for (i in x) {
   + if(i < 60) {
             +       new <- c(new,'S')
   + }
             + else if (i > 72) {
   +       new <- c(new,'T')
   + }
             +   else {
   +      new <- c(new,'A')
   + }
             }

Ans 3: Dataframe "newdataframe" consists the required sections of diamonds.

           > newdf <- diamonds$cut == 'Ideal'

           > newdataframe <- diamonds[newdf,]

           > newdataframe

Ans 4: > nrow(diamonds)

Ans 5: premium and ecolor are boolean vectors while Premium and EandPre are numeric vectors.

           > premium <- diamonds$cut == "Premium"

           > Premium <- diamonds[premium,]

           > ecolor <- Premium$color == "E"

           > EandPre <- Premium[ecolor,]

           > median(EandPre$price)

Ans 6: carat is a boolean vector and Carat is a dataframe.

            > carat <- diamonds$carat > 2

            > Carat <- diamonds[carat,]

           > y <- Carat$price

           > hist(y)