R 简明教程

R - Operators

An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. R language is rich in built-in operators and provides following types of operators.

Types of Operators

We have the following types of operators in R programming −

  1. Arithmetic Operators

  2. Relational Operators

  3. Logical Operators

  4. Assignment Operators

  5. Miscellaneous Operators

Arithmetic Operators

Following table shows the arithmetic operators supported by R language. The operators act on each element of the vector.

Operator

Description

Example

+

Adds two vectors

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v+t) it produces the following result − [1] 10.0 8.5 10.0

−

Subtracts second vector from the first

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v-t) it produces the following result − [1] -6.0 2.5 2.0

*

Multiplies both vectors

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v*t) it produces the following result − [1] 16.0 16.5 24.0

/

Divide the first vector with the second

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v/t) When we execute the above code, it produces the following result − [1] 0.250000 1.833333 1.500000

%%

Give the remainder of the first vector with the second

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v%%t) it produces the following result − [1] 2.0 2.5 2.0

%/%

The result of division of first vector with second (quotient)

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v%/%t) it produces the following result − [1] 0 1 1

^

The first vector raised to the exponent of second vector

Live Demov ← c( 2,5.5,6) t ← c(8, 3, 4) print(v^t) it produces the following result − [1] 256.000 166.375 1296.000

Relational Operators

Following table shows the relational operators supported by R language. Each element of the first vector is compared with the corresponding element of the second vector. The result of comparison is a Boolean value.

Operator

Description

Example

>

Checks if each element of the first vector is greater than the corresponding element of the second vector.

Live Demov ← c(2,5.5,6,9) t ← c(8,2.5,14,9) print(v>t) it produces the following result − [1] FALSE TRUE FALSE FALSE

<

Checks if each element of the first vector is less than the corresponding element of the second vector.

Live Demov ← c(2,5.5,6,9) t ← c(8,2.5,14,9) print(v < t) it produces the following result − [1] TRUE FALSE TRUE FALSE

==

Checks if each element of the first vector is equal to the corresponding element of the second vector.

Live Demov ← c(2,5.5,6,9) t ← c(8,2.5,14,9) print(v == t) it produces the following result − [1] FALSE FALSE FALSE TRUE

⇐

Checks if each element of the first vector is less than or equal to the corresponding element of the second vector.

Live Demov ← c(2,5.5,6,9) t ← c(8,2.5,14,9) print(v⇐t) it produces the following result − [1] TRUE FALSE TRUE TRUE

>=

Checks if each element of the first vector is greater than or equal to the corresponding element of the second vector.

Live Demov ← c(2,5.5,6,9) t ← c(8,2.5,14,9) print(v>=t) it produces the following result − [1] FALSE TRUE FALSE TRUE

!=

Checks if each element of the first vector is unequal to the corresponding element of the second vector.

Live Demov ← c(2,5.5,6,9) t ← c(8,2.5,14,9) print(v!=t) it produces the following result − [1] TRUE TRUE TRUE FALSE

Logical Operators

下表显示了 R 语言支持的逻辑运算符。它仅适用于逻辑、数值或复杂类型的向量。大于 1 的所有数字都被视为逻辑值 TRUE。

第一个向量的每个元素都与第二个向量的对应元素进行比较。比较的结果是布尔值。

Operator

Description

Example

&

它称为元素级逻辑 AND 运算符。它将第一个向量的每个元素与第二个向量的对应元素组合在一起，如果两个元素都是 TRUE，则给出一个输出 TRUE。

Live Demo v ← c(3,1,TRUE,2+3i)t ← c(4,1,FALSE,2+3i)print(v&t)产生以下结果 −[1] TRUE TRUE FALSE TRUE

它称为元素级逻辑 OR 运算符。它将第一个向量的每个元素与第二个向量的对应元素组合在一起，如果其中一个元素是 TRUE，则给出一个输出 TRUE。

Live Demo v ← c(3,0,TRUE,2+2i)t ← c(4,0,FALSE,2+3i)print(v

t)产生以下结果 −[1] TRUE FALSE TRUE TRUE

!

逻辑运算符 && 和 || 仅考虑向量的第一个元素，并给出一个单元素向量的输出。

Operator

Description

Example

&&

称为逻辑 AND 运算符。获取两个向量的第一个元素，并且仅当两者都为 TRUE 时才给 TRUE。

Live Demo v ← c(3,0,TRUE,2+2i)t ← c(1,3,TRUE,2+3i)print(v&&t)产生以下结果 −[1] TRUE

称为逻辑 OR 运算符。获取两个向量的第一个元素，并且如果其中一个为 TRUE，则给 TRUE。

Live Demo v ← c(0,0,TRUE,2+2i)t ← c(0,3,TRUE,2+3i)print(v

Assignment Operators

这些运算符用于为向量分配值。

Operator

Description

Example

<− or = or <<−

Called Left Assignment

Live Demo v1 ← c(3,1,TRUE,2+3i)v2 <← c(3,1,TRUE,2+3i)v3 = c(3,1,TRUE,2+3i)print(v1)print(v2)print(v3)产生以下结果 −[1] 3+0i 1+0i 1+0i 2+3i[1] 3+0i 1+0i 1+0i 2+3i[1] 3+0i 1+0i 1+0i 2+3i

→ or →>

Called Right Assignment

Live Demo c(3,1,TRUE,2+3i) → v1c(3,1,TRUE,2+3i) →> v2print(v1)print(v2)产生以下结果 −[1] 3+0i 1+0i 1+0i 2+3i[1] 3+0i 1+0i 1+0i 2+3i

Miscellaneous Operators

这些运算符用于特殊目的，而不是常规的数学或逻辑运算。

Operator

Description

Example

:

冒号运算符。它为向量按顺序创建一系列数字。

Live Demo v ← 2:8print(v)产生以下结果 −[1] 2 3 4 5 6 7 8

%in%

此运算符用于识别元素是否属于向量。

Live Demo v1 ← 8v2 ← 12t ← 1:10print(v1 %in% t)print(v2 %in% t)产生以下结果 −[1] TRUE[1] FALSE

%*%

此运算符用于用矩阵与其转置相乘。

Live Demo M = matrix( c(2,6,5,1,10,4), nrow = 2,ncol = 3,byrow = TRUE)t = M %*% t(M)print(t)产生以下结果 − [,1] [,2][1,] 65 82[2,] 82 117