- Create vectors ‘u’ & ‘v’; compare ‘u’ > ‘v’
u <- c(5,2,8)
v <- c(1,3,9)
u > v
## [1] TRUE FALSE FALSE
- Create function = x+1 & apply function to vectors ‘u’ &
‘v’
w <- function(x) return(x+1)
w(u)
## [1] 6 3 9
w(v)
## [1] 2 4 10
- Create function = x**2+1 & apply function to vectors ‘u’ &
‘v’
m <- function(x) return(x**2+1)
m(u)
## [1] 26 5 65
m(v)
## [1] 2 10 82
- Create function = x^2-1 & apply function to vectors ‘u’ &
‘v’
m1 <- function(x) return(x^2-1)
m1(u)
## [1] 24 3 63
m1(v)
## [1] 0 8 80
- Creat vector ‘y’ & use rounding function to the nearest integer,
save in ‘z’ & show ‘z’:
y <- c(1.2,3.9,0.4)
z <- round(y)
z
## [1] 1 4 0
- Creat vector ‘r’ & use rounding function to the nearest integer,
save in ‘r1’ & show ‘r1’:
r <- c(0.25,0.9,2.1,4.7,5.1)
r1 <- round(r)
r1
## [1] 0 1 2 5 5
- Create vectorized function with scalar arguments.
f <- function(x,c) return((x+c)^2)
f(1:3, 0)
## [1] 1 4 9
f(1:3, 1)
## [1] 4 9 16
- Create vectorized function with scalar arguments.
f1 <- function(x,c) return((x-c)^2)
f1(1:3, 0)
## [1] 1 4 9
f1(1:3, 1)
## [1] 0 1 4
- Create function; add vectors ‘x’ & ‘x2’; perform function and
show results; modify result to view as 2 columns
z12 <- function(z) return(c(z,z^2))
x <- 1:8
z12(x)
## [1] 1 2 3 4 5 6 7 8 1 4 9 16 25 36 49 64
x2 <- 1:5
z12(x2)
## [1] 1 2 3 4 5 1 4 9 16 25
matrix(z12(x),ncol=2)
## [,1] [,2]
## [1,] 1 1
## [2,] 2 4
## [3,] 3 9
## [4,] 4 16
## [5,] 5 25
## [6,] 6 36
## [7,] 7 49
## [8,] 8 64
matrix(z12(x2),ncol=2)
## [,1] [,2]
## [1,] 1 1
## [2,] 2 4
## [3,] 3 9
## [4,] 4 16
## [5,] 5 25
- Create vector ‘x’ with NA value => mean calculated as NA; exclude
NA value to calculate mean correctly; the NA issue doesn’t occur if NULL
is used since R reads it as string of characters
x <- c(88,NA,12,168,13)
x
## [1] 88 NA 12 168 13
mean(x)
## [1] NA
mean(x,na.rm=T)
## [1] 70.25
x <- c(88,NULL,12,168,13)
mean(x)
## [1] 70.25
- Create vector ‘x’ and determine data characteristics
x <- c(5,NA,12)
mode(x[1])
## [1] "numeric"
mode(x[2])
## [1] "numeric"
- Create vector ‘y’ and determine data characteristics
y <- c("abc","def",NA)
mode(y[2])
## [1] "character"
mode(y[3])
## [1] "character"