DATA 101 Assignment 2
Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit
DATA 101
Assignment 2
Please submit your assignment as an R script file named with your last name, student number, assignment number and with the suffix R. For example, if Joe Smith, student number 87654321 hands in Assignment 2, he would name the file Smith87654321A2 .R.
Within your answer file, include answers with your R code preceded by the # sign. For example, to answer the 5th question on an assignment which is “Perform the calculation
2 + 2”, you would type
# Question 5
2 + 2 #coding
# 4 (your answer here )
Due Date: October 9, 2020
In each question below, type the required lines of R code, together with the answer to the question.
1. (7 marks) Consider the chickwts data frame that is built into R.
(a) Display the 14th row of this data frame.
(b) Using one R command, display the 7th, 14th and 37th elements of weight column.
(c) Extract the observations from this data frame that correspond to casein, and assign the resulting subset to chickwtsCasein.
(d) Find the average of the weights in chickwtsCasein.
(e) Create a new column which contains a factor called Feed which has levels Casein, Horsebean, and so on. That is, Feed is the same as feed but all entries are capitalized.
(f) Extract the subset from chickwts that contains all observations where weight is less than 240. Call the resulting data frame chick240.
(g) Use the table() function to create a vector called chick240Table as in
chick240Table <- table(chick240$feed)
Create a bar plot of the counts in chick240Table.
2. (8 marks) If it is not already, installed, install the R package DAAG either by using the
menu system in RStudio, or by typing the following into an R session: install .packages("DAAG")
Load the package into an R session, for example, by typing
library(DAAG)
(a) How many observations are in the cuckoos data frame?
(b) What is the length measurement for the 27th observation.
(c) List the elements in the 40th row of the data frame.
(d) Use the levels function to identify the types of birds that make up the species factor of the cuckoos data frame.
(e) Again, using the levels() function, create a new factor called m .pipitFactor which has levels meadow .pipit and other, and where other is the value assigned to those elements which correspond to any bird species other than meadow .pipit.
(f) Create a logical vector column in the data frame called m .pipit which contains
TRUE in the rows corresponding to meadow .pipit and FALSE in the other rows.
(g) Create two new data frames: one called cuckoosMPipit, which consists only of the rows in cuckoos corresponding to meadow .pipit and one called cuckoosOther, which contains all other rows.
(h) Create another data frame called cuckoosLongLength which contains all observa- tions in the cuckoos data frame where the length exceeds 23. Find the average of the breadth observations in cuckoosLongLength.
2022-10-06