Question

3. Generate a vector u with 100 elements randomly selected (uniformly) from 1 to 40. Then generate a vector v with 100 elements randomly selected with a normal distribution of mean 20 and standard deviation 5 a) Write the vector to a file 'data.txt', using ,' as separator. (b) Remove the variable u (c) Scan the file and retrieve the variable u. (d) Print the 5-summary of the vector u (e) Plot the boxplot of u (f) Plot the histogram of v. (g) Generate another vector w with 500 elements with the same characteristics as v, i.e. random elements with a normal distribution of mean 20 and standard deviation 5. Plot the histogram of w as wel

Answer 1

ANSWER:

First create u and v -

A <- 1:40
u <- sample((A),
size = 100,
replace = TRUE)
v <- matrix( rnorm(1*100,mean=20,sd=5), 1,100)

Answer (a) --

vectStr=paste(as.character(u), sep="' '", collapse=",")

sink("outfile.txt")
cat(vectStr)
cat("\n")
sink()

Answer (b) --

> u<-runif (100, 1, 40) > v<-rnorm (100, 20, 5) write. table (u, "С:/users/Computer/Desktop/data.txt", rm (u) > sep-",") > > u Error: object u'not found

Answer(c) --

myMatrix <- as.matrix(read.table("outfile.txt", sep=",", header=TRUE)

lists<-split(myMatrix, f = 1:2)
u<-lists[1]

Answer(d) --

> u<-read . table ("C:/Users/Computer/Desktop/data. txt", header > #D# >summary (u) TRUE, ",") = зер = Min : 1.036 1st Qu. :12.615 Median :21.958 Mean19.890 3rd Qu. :27.433 Max. 39.282 >ul<-runif (100,1,40) > u2<-runif (100,1,40) >u3<-runif (100,1,40) > u4<-runif (100,1,40) >summary (u1) Min. 1st u. Median Mean 3rd Qu. Max. 1.431 9.467 20.579 20.591 30.362 39.685 > summary (u2) Min. 1st u. Median Mean 3rd Qu. Max. 1.365 13.128 20.342 20.673 30.045 39.834 summary (u3) Min. 1st u. Median Mean 3rd Qu. Max. 1.188 13.089 20.87821.785 30.56639.664 >summary (u4) Min. 1st u. Median Mean 3rd Qu. 1.131 10.622 20.00720.484 32.033 39.837 Max. > #E# >boxplot (u)

Answer(e) --

> boxplot (u, xlab='' u " , main="Boxplot of u")

Boxplot of u 電y

Answer(f) --

> hist (v, x1ab="v" , main="Histogram of v'' )

Histogram of v 髦3 髦3 12 5 10 15202530 35 40

Answer(g) --

w<-rnorm (500,20, 5) > hist (w,xlab-w,main-"Histogram of w")

Histogram of w 髦3 髦3 12 12 髦3 10 20 30 40 0