date()
## [1] "Tue Sep 11 15:00:34 2012"
Due Date: September 13, 2012
Total Points: 30
1 The following values are the annual number hurricanes that have hit the United States since 1990. Follow instructions and answer questions by typing the appropriate R commands.
0 1 1 1 0 2 2 1 3 3 0 0 1 2 6 6 0 1 3 0 1
a. Enter the data into R. (2)
Hur=c(0, 1, 1, 1, 0, 2, 2, 1, 3, 3, 0, 0, 1, 2, 6, 6, 0, 1, 3, 0, 1)
b. How many years are there? (2)
length(Hur)
c. What is the total number of hurricanes over all years? (2)
sum(Hur)
2 Answer the following questions by typing the appropriate R commands.
a. Create a vector of numbers starting with 0 and ending with 25. (2)
N=seq(0,25)
b. What is the length of this vector? (2)
length(N)
c. Create a new vector from the original vector by subtracting the mean value over all numbers in the vector. (2)
M=(N-mean(N))
3 Suppose you keep track of your mileage each time you fill up. At your last 8 fill-ups the mileage was
65311 65624 65908 66219 66499 66821 67145 67447
a. Enter these numbers into a vector called miles. (2)
miles=c(65311, 65624, 65908, 66219, 66499, 66821, 67145, 67447)
b. Use the function diff() to determine the number of miles between fill-ups. (2)
f=diff(miles)
c. What is the maximum, minimum, and mean number of miles between fill-ups? (3)
max(f)
min(f)
mean(f)
4 Create the following sequences using the seq() and rep() functions as appropriate.
a. “a”, “a”, “a”, “a” (2)
rep("a", 4)
b. The odd numbers in the interval from 1 to 100 (2)
seq(1,100, by=2)
c. 1, 1, 1, 2, 2, 2, 3, 3, 3 (2)
rep(c(1,2,3), c(3, 3,3))
d. 1, 1, 1, 2, 2, 3 (2)
rep(c(1,2,3), c(3, 2,1))
e. 1, 2, 3, 4, 5, 4, 3, 2, 1 (3) Hint: Use the c() function.
c(seq(1,5),seq(4,1))