向量是最基本的R语言数据对象，有六种类型的原子向量。 它们是逻辑，整数，双精度，复杂，字符和原始。
创建向量

单元素向量

即使在R语言中只写入一个值，它也将成为长度为1的向量，并且属于上述向量类型之一。

Atomic vector of type character.

print("abc");

Atomic vector of type double.

print(12.5)

Atomic vector of type integer.

print(63L)

Atomic vector of type logical.

print(TRUE)

Atomic vector of type complex.

print(2+3i)

Atomic vector of type raw.

print(charToRaw('hello'))
当我们执行上面的代码，它产生以下结果 -
[1] "abc"
[1] 12.5
[1] 63
[1] TRUE
[1] 2+3i
[1] 68 65 6c 6c 6f
多元素向量

对数值数据使用冒号运算符

Creating a sequence from 5 to 13.

v <- 5:13
print(v)

Creating a sequence from 6.6 to 12.6.

v <- 6.6:12.6
print(v)

If the final element specified does not belong to the sequence then it is discarded.

v <- 3.8:11.4
print(v)
当我们执行上面的代码，它产生以下结果 -
[1] 5 6 7 8 9 10 11 12 13
[1] 6.6 7.6 8.6 9.6 10.6 11.6 12.6
[1] 3.8 4.8 5.8 6.8 7.8 8.8 9.8 10.8
使用sequence (Seq.)序列运算符

Create vector with elements from 5 to 9 incrementing by 0.4.

print(seq(5, 9, by = 0.4))
当我们执行上面的代码，它产生以下结果 -
[1] 5.0 5.4 5.8 6.2 6.6 7.0 7.4 7.8 8.2 8.6 9.0
使用C()函数
如果其中一个元素是字符，则非字符值被强制转换为字符类型。

The logical and numeric values are converted to characters.

s <- c('apple','red',5,TRUE)
print(s)
当我们执行上面的代码，它产生以下结果 -
[1] "apple" "red" "5" "TRUE"
访问向量元素

使用索引访问向量的元素。 []括号用于建立索引。 索引从位置1开始。在索引中给出负值会丢弃来自result.TRUE，FALSE或0和1的元素，也可用于索引。

Accessing vector elements using position.

t <- c("Sun","Mon","Tue","Wed","Thurs","Fri","Sat")
u <- t[c(2,3,6)]
print(u)

Accessing vector elements using logical indexing.

v <- t[c(TRUE,FALSE,FALSE,FALSE,FALSE,TRUE,FALSE)]
print(v)

Accessing vector elements using negative indexing.

x <- t[c(-2,-5)]
print(x)

Accessing vector elements using 0/1 indexing.

y <- t[c(0,0,0,0,0,0,1)]
print(y)
当我们执行上面的代码，它产生以下结果 -
[1] "Mon" "Tue" "Fri"
[1] "Sun" "Fri"
[1] "Sun" "Tue" "Wed" "Fri" "Sat"
[1] "Sun"
向量操作

向量运算

可以添加，减去，相乘或相除两个相同长度的向量，将结果作为向量输出。

Create two vectors.

v1 <- c(3,8,4,5,0,11)
v2 <- c(4,11,0,8,1,2)

Vector addition.

add.result <- v1+v2
print(add.result)

Vector substraction.

sub.result <- v1-v2
print(sub.result)

Vector multiplication.

multi.result <- v1*v2
print(multi.result)

Vector division.

divi.result <- v1/v2
print(divi.result)
当我们执行上面的代码，它产生以下结果 -
[1] 7 19 4 13 1 13
[1] -1 -3 4 -3 -1 9
[1] 12 88 0 40 0 22
[1] 0.7500000 0.7272727 Inf 0.6250000 0.0000000 5.5000000
向量元素回收

如果我们对不等长的两个向量应用算术运算，则较短向量的元素被循环以完成操作。
v1 <- c(3,8,4,5,0,11)
v2 <- c(4,11)

V2 becomes c(4,11,4,11,4,11)

add.result <- v1+v2
print(add.result)

sub.result <- v1-v2
print(sub.result)
当我们执行上面的代码，它产生以下结果 -
[1] 7 19 8 16 4 22
[1] -1 -3 0 -6 -4 0
向量元素排序

向量中的元素可以使用sort()函数排序。
v <- c(3,8,4,5,0,11, -9, 304)

Sort the elements of the vector.

sort.result <- sort(v)
print(sort.result)

Sort the elements in the reverse order.

revsort.result <- sort(v, decreasing = TRUE)
print(revsort.result)

Sorting character vectors.

v <- c("Red","Blue","yellow","violet")
sort.result <- sort(v)
print(sort.result)

Sorting character vectors in reverse order.

revsort.result <- sort(v, decreasing = TRUE)
print(revsort.result)
当我们执行上面的代码，它产生以下结果 -
[1] -9 0 3 4 5 8 11 304
[1] 304 11 8 5 4 3 0 -9
[1] "Blue" "Red" "violet" "yellow"
[1] "yellow" "violet" "Red" "Blue"