ls()
> ls()
character(0)
> data <- c(1, 2, 4, 5)
> string <- "I like R"
> ls()
[1] "data" "string"
> rm(data)
> ls()
[1] "string"
> a <- 1
> A <- 2
> ls()
[1] "a" "A" "string"
> v <- c(4, 7, 23, 56, 32)
> length(v)
[1] 5
> mode(v)
[1] "numeric"
> c <- c(1, 2, 3, "r")
> c
[1] "1" "2" "3" "r"
> c[2] <- "test"
> c
[1] "1" "test" "3" "r"
> x <- c(4, 8, 9, 15, 24)
> y <- sqrt(x)
> y
[1] 2.000000 2.828427 3.000000 3.872983 4.898979
> z <- x + y
> z
[1] 6.00000 10.82843 12.00000 18.87298 28.89898
> x <- c(1, 1, 1, 1, 1, 1)
> y <- c(2, 2, 2)
> z <- x + y
> z
[1] 3 3 3 3 3 3
> x <- 1:1000
> length(x)
[1] 1000
> x <- seq(1, 10, 2)
> x
[1] 1 3 5 7 9
> x <- rep(5, 10)
> x
[1] 5 5 5 5 5 5 5 5 5 5
> rep(1:3, 3)
[1] 1 2 3 1 2 3 1 2 3
> rnorm(10)
[1] -1.47829892 1.69033876 -0.49436375 0.46905045
[5] -1.29792678 -0.20725778 -0.05561737 0.48251510
[9] 0.15097134 0.77595026
> rnorm(6, mean=6, sd=2)
[1] 9.3389189 6.5964500 7.0747597 8.1193465 9.4957167
[6] 0.5747525
> x <- c(0, -3, 4, -1, 45, 98, -12)
> x[x>0]
[1] 4 45 98
> x[x<=-2 | x>5]
[1] -3 45 98 -12
> x[-5]
[1] 0 -3 4 -1 98 -12
> x[-(1:3)]
[1] -1 45 98 -12