Description
1. Consider the built‐in data frame pressure.
(a) Plot pressure against temperature, and use the following command to pass a curve
through these data:
curve((0.168 + 0.007*x)ˆ(20/3), from = 0, to = 400, add = TRUE)
(b) Now, apply the power transformation y3/20 to the pressure data values. Plot these
transformed values against temperature. Is a linear or nonlinear relationship evident now?
Use the abline() function to pass a straight line through the points. (You need an
intercept and slope for this – see the part (a) of this question to obtain appropriate values.)
(c) Add a suitable title to the graph.
(d) Re‐do the above plots, but use the mfrow() function to display them in a 1 × 2 layout
on the graphics page. Suppress the surrounding box and arrange the numeric axis labels to
be horizontal. A sample output is given below. (see help(par))
2. Write a function named alt_matrix() which accept a positive integer n and return a
square matrix with alternating 0 and 1 as shown below.
> alt_matrix(7)
[,1] [,2] [,3] [,4] [,5] [,6] [,7]
[1,] 0 1 0 1 0 1 0
[2,] 1 0 1 0 1 0 1
[3,] 0 1 0 1 0 1 0
[4,] 1 0 1 0 1 0 1
[5,] 0 1 0 1 0 1 0
[6,] 1 0 1 0 1 0 1
[7,] 0 1 0 1 0 1 0
3. Use R to draw the following graph.
Note: the four colours are “red”, “orange”, “green”, and “blue”.
4. A twin prime is a pair of primes (x, y), such that y = x + 2. Construct a list of all twin primes
less than 1000.
You should submit a file asg2.r via Blackboard, which contains all the R codes you use to
finish this assignment. The codes should be commented as clearly as possible. Written work
(if any) should also be submitted to the assignment drop‐box.
