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[Workspace loaded from ~/.RData] Question1

1, creating numeric vector

v<-rep(1:5,4) v [1] 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 Question#2

2changing numeric vector into character

c<-as.character(v) c [1] "1" "2" "3" "4" "5" "1" "2" "3" "4" "5" "1" "2" [13] "3" "4" "5" "1" "2" "3" "4" "5" Question #3 changing numeric vector into factor vector f<-factor(v) f [1] 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 Levels: 1 2 3 4 5 Question#4 number of levels that the vector has l<-nlevels(f) l [1] 5 Question #5 Creating vector with a formula, sapply r<-sapply(v, function(x) 3_x^2-4_x +1) r [1] 0 5 16 33 56 0 5 16 33 56 0 5 16 33 56 0 [17] 5 16 33 56

Question #7 Creating a named list v=list(gender=c(1,2), status=c("single","married")) v $gender [1] 1 2

$status [1] "single" "married"

v[["gender"]] [1] 1 2 v$gender [1] 1 2

Question#8 Creating a data frame m<-data.frame(matrix(0, ncol=4, nrow =10)) m X1 X2 X3 X4 1 0 0 0 0 2 0 0 0 0 3 0 0 0 0 4 0 0 0 0 5 0 0 0 0 6 0 0 0 0 7 0 0 0 0 8 0 0 0 0 9 0 0 0 0 10 0 0 0 0 Question #10, read a csv file temperature= read.csv("temperature.csv")

Question #11 read txt file from different directory setwd("") # set working directory setwd("C:/measurements.txt") measurements = read.table("c":/measurments.txt") # read text file

Question#13 factorial = function(n) { •f =1 •for (i in 1:n) • f = f*i •f •} factorial(12) [1] 479001600

Question#19 seq(from = 20, t0 = 50, by =5) [1] 20 25 30 40 45 50

Question#20 rep("example", 10)

gcoulibaly / WEEK2-_QUIZ_IS607

Quiz #4

1, creating numeric vector

2changing numeric vector into character