1) Create an integer variable e holding the value 42! Check the object class of e with class()!
e <- 42L class(e) ## [1] "integer"
2) Convert e to the character data type with as.character()! Check the object class again!
e <- as.character(e) class(e) ## [1] "character"
3) Create a character vector friends with four names from your circle of friends or acquaintances!
friends <- c("Anna", "Otto", "Natan", "Ede")
friends
## [1] "Anna" "Otto" "Natan" "Ede"
4) Index the second element from the vector friends!
friends[2] ## [1] "Otto"
5) Replace the first element of the vector friends with “Isolde” and check the updated vector again!
freunde[1] <- "Isolde" freunde ## [1] "Isolde" "Otto" "Natan" "Ede"
6) Create a vector v1 from the following elements 1, “Hello”, 2, “World” ! Check the object class!
v1 <- c(1, "Hello", 2, "World") v1 ## [1] "1" "Hello" "2" "World" class(v1) ## [1] "character"
7) Create a vector v2 with numerical values (only integers) ranging from 4 to 10!
v2 <- c(4, 5, 6, 7, 8, 9, 10) v2 ## [1] 4 5 6 7 8 9 10 # or use the sequence operator ":" v2 <- c(4:10) v2 ## [1] 4 5 6 7 8 9 10
8) Index the first three elements from v2!
v2[1:3] ## [1] 4 5 6 # or: v2[ c(1, 2, 3) ] ## [1] 4 5 6
9) Index all elements of v2 except the second element and save the result as v2.subset!
v2.subset <- v2[-2] v2.subset ## [1] 4 6 7 8 9 10
10) Use the length () function to find out the length of v2.subset (= the number of elements in the vector)!
length(v2.subset) ## [1] 6
11) Calculate the arithmetic mean of vector v2! In addition, determine the standard deviation of v2.subset!
mean(v2) ## [1] 7 sd(v2.subset) ## [1] 2.160247