You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
117 lines
1.4 KiB
117 lines
1.4 KiB
c(2, 3, 5)
|
|
length(c("aa", "bb", "cc", "dd", "ee"))
|
|
n = c(2, 3, 5)
|
|
s = c("aa", "bb", "cc", "dd", "ee")
|
|
c(n, s)
|
|
a = c(1, 3, 5, 7)
|
|
b = c(1, 2, 4, 8)
|
|
5 * a
|
|
a + b
|
|
a - b
|
|
a * b
|
|
u = c(10, 20, 30)
|
|
v = c(1, 2, 3, 4, 5, 6, 7, 8, 9)
|
|
u + v
|
|
a[0]
|
|
a[1]
|
|
b
|
|
b[0]
|
|
b[1]
|
|
b
|
|
b[-2]
|
|
b[20]
|
|
b[c(2, 3)]
|
|
a
|
|
a[c(1, 4)]
|
|
a
|
|
a[1:4]
|
|
a[1:3]
|
|
a[c(FALSE, TRUE, FALSE, TRUE)]
|
|
v = c("Mary", "Sue")
|
|
names(v)
|
|
names(v) = c("First", "Last")
|
|
names(v)
|
|
v["First"]
|
|
A = matrix(
|
|
c(2, 4, 3, 1, 5, 7),
|
|
nrow=2,
|
|
ncol=3,
|
|
byrow=TRUE)
|
|
A
|
|
A[1, 3]
|
|
A[2,]
|
|
A[, c(1, 3)]
|
|
dimnames(A) = list(
|
|
c("row1", "row2"),
|
|
c("col1", "col2", "col3"))
|
|
A
|
|
A["row2", "col3"]
|
|
B = matrix(
|
|
c(2, 4, 3, 1, 5, 7),
|
|
nrow=3,
|
|
ncol=2)
|
|
B
|
|
t(B)
|
|
C = matrix(
|
|
c(7, 4, 2),
|
|
nrow=3,
|
|
ncol=1)
|
|
C
|
|
cbind(B, C)
|
|
D = matrix(
|
|
c(6, 2),
|
|
nrow=1,
|
|
ncol=2)
|
|
D
|
|
B
|
|
BD = rbind(B, D)
|
|
BD
|
|
c(B)
|
|
n = c(2, 3, 5)
|
|
s = c("aa", "bb", "dd", "ee")
|
|
b = c(TRUE, FALSE, TRUE, FALSE, FALSE)
|
|
x = list(n, s, b, 3)
|
|
x
|
|
x[2]
|
|
x[1]
|
|
x[2]
|
|
x[[2]]
|
|
x[[2]][1] = "DORP"
|
|
x[[2]]
|
|
s
|
|
v = list(bob=list("Bob", "Johnson", c(2, 3, 5)), john=list("John", "Smythe", c(1, 4, 6)))
|
|
v
|
|
v["bob"]
|
|
v[["bob"]]
|
|
v[["bob"]][[1]]
|
|
v[["bob"]][[1]] = "Robert"
|
|
v["bob"]
|
|
v$bob
|
|
v$john
|
|
v$john[1]
|
|
v$john[[1]]
|
|
v$john[[1]] =
|
|
"Johnny"
|
|
v$john
|
|
attach(v)
|
|
bob
|
|
detach(v)
|
|
bob
|
|
mtcars
|
|
n = c(2, 3, 5)
|
|
s = c("aa", "bb", "cc")
|
|
b = c(TRUE, FALSE, TRUE)
|
|
df = data.frame(n, s, b)
|
|
mtcars["Mazda RX4", "mpg"]
|
|
nrow(mtcars)
|
|
ncol(mtcars)
|
|
ncol(s)
|
|
s
|
|
B
|
|
nrow(B)
|
|
ncol(B)
|
|
head(mtcars)
|
|
q()
|
|
s
|
|
q()
|