[Solved] STAT823 Homework 2-R Objects

Launch RStudio and open a new RMarkdown file or use the class RMarkdown template provided and save it on your working directory as a .Rmd file. At the end of the activity, save your pdf generated from RMarkdown+Knitr and submit it in the Blackboard dropbox.

Show all your work. Late submission will attract a penalty of 10 points per day after the due date.

If you have questions, please post them on the lesson discussion board.

1. (a) Create a vector of length 10 and fill it with a sequence of integers.

(b) Coerce the vector into a matrix of 5 rows and 2 columns. (c) Name the columns of the matrix A and B.

2. Assume that we have recorded the names and ages for four people: James is 27, Art is 42, Kate is 29, and Alex is 33.
   • Create a vector of names and a vector of ages from the data, making sure that you keep the ordering of the elements consistent.
   • Use the class() function to print the class metadata R has stored for each vector.

• Using data.frame(), combine the two vectors into a dataframe and name the columns something informative. Print out the dataframe.

3. A hypothetical data with heights (in cm) and weights (in kg) of 10 family members are shown below:

height (cm) weight (kg)

• Create a vector called ht corresponding to the heights of the 11 family members. Assign the names of the family₁₀ members to the names attribute of this vector.
• Create a vector called wt corresponding to the family members weights.
• Compute the body mass index (BMI: units should be kg/_m²) of each person where BMI = weight/height².
• Identify the persons who have the lowest and highest BMI and calculate the standard deviation of the BMI.