1. Matrices
a <- c(1,1,1,2,2,2,3,3,3)
b <- matrix(a,nrow=3)
b
## [,1] [,2] [,3]
## [1,] 1 2 3
## [2,] 1 2 3
## [3,] 1 2 3
x <- c(1,1,1,2,2,2,3,3,3)
y <- matrix(a, nrow=3, byrow=TRUE) # matrix class is a two-dimensional structure
y
## [,1] [,2] [,3]
## [1,] 1 1 1
## [2,] 2 2 2
## [3,] 3 3 3
## 1.1 Indexing values in a matrix
b[1,1]
## [1] 1
b[1,]
## [1] 1 2 3
b[,1]
## [1] 1 1 1
2. Strings
a <- "Hello World"
b <- "You are so smart"
c <- "1"
class(a) # putting quotes around the characters to store as a string
## [1] "character"