Sas 简明教程

SAS - Operators

SAS 中的运算符是一种符号，用于数学、逻辑或比较表达式中。这些符号内置于 SAS 语言中，许多运算符可以组合到单个表达式中以提供最终输出。

An operator in SAS is a symbol which is used in a mathematical, logical or comparison expression. These symbols are in-built into the SAS language and many operators can be combined in a single expression to give a final output.

下面是 SAS 运算符类别的列表。

Below is a list of SAS category of operators.

  1. Arithmetic Operators

  2. Logical Operators

  3. Comparison Operators

  4. Minimum/Maximum Operators

  5. Concatenation Operator

我们将逐个查看每个运算符。运算符始终与作为 SAS 程序正在分析的数据一部分的变量一起使用。

We will look at each of the one by one. The operators are always used with variables that are part of the data that is being analyzed by the SAS program.

Arithmetic Operators

下表描述了算术运算符的详细信息。我们假设两个数据变量 V1 和 V2*with values *8 和 4 。

The below table describes the details of the arithmetic operators. Let’s assume two data variables V1 and V2*with values *8 and 4 respectively.

Operator

Description

Example

+

Addition

V1+V2=12

-

Subtraction

V1-V2=4

*

Multiplication

V1*V2=32

/

Division

V1/V2=2

**

Exponentiation

V1**V2=4096

Example

DATA MYDATA1;
input @1 COL1 4.2	@7 COL2 3.1;
Add_result = COL1+COL2;
Sub_result = COL1-COL2;
Mult_result = COL1*COL2;
Div_result = COL1/COL2;
Expo_result = COL1**COL2;
datalines;
11.21 5.3
3.11  11
;
PROC PRINT DATA = MYDATA1;
RUN;

通过运行以上代码，我们得到以下输出。

On running the above code, we get the following output.

operators arithmrtic

Logical Operators

下表描述了逻辑运算符的详细信息。这些运算符计算表达式的真值。因此，逻辑运算符的结果始终是 1 或 0。我们假设两个数据变量 V1 和 V2*with values *8 和 4 。

The below table describes the details of the logical operators. These operators evaluate the Truth value of an expression. So the result of logical operators is always a 1 or a 0. Let’s assume two data variables V1 and V2*with values *8 and 4 respectively.

Operator

Description

Example

&

The AND Operator. If both data values evaluate to true then the result is 1 else it is 0.

(V1>2 & V2 > 3) gives 0.

The OR Operator. If any one of the data values evaluate to true then the result is 1 else it is 0.

(V1>9 & V2 > 3) is 1.

~

The NOT Operator. The result of NOT operator in form of an expression whose value is FALSE or a missing value is 1 else it is 0.

Example

DATA MYDATA1;
input @1 COL1 5.2	@7 COL2 4.1;
and_=(COL1 > 10 & COL2 > 5 );
or_ = (COL1 > 12 | COL2 > 15 );
not_ = ~( COL2 > 7 );
datalines;
11.21 5.3
3.11  11.4
;
PROC PRINT DATA = MYDATA1;
RUN;

通过运行以上代码，我们得到以下输出。

On running the above code, we get the following output.

operators logical

Comparison Operators

下表对比较运算符的详细信息进行了描述。这些运算符将变量的值进行比较，结果为真值，真为 1，假为 0。让我们假设两个数据变量分别为 V1 、 V2*with values *8 和 4 。

The below table describes the details of the comparison operators. These operators compare the values of the variables and the result is a truth value presented by 1 for TRUE and 0 for False. Let’s assume two data variables V1 and V2*with values *8 and 4 respectively.

Operator

Description

Example

=

The EQUAL Operator. If both data values are equal then the result is 1 else it is 0.

(V1 = 8) gives 1.

^=

The NOT EQUAL Operator. If both data values are unequal then the result is 1 else it is 0.

(V1 ^= V2) gives 1.

<

The LESS THAN Operator.

(V2 < V2) gives 1.

⇐

The LESS THAN or EQUAL TO Operator.

(V2 ⇐ 4) gives 1.

>

The GREATER THAN Operator.

(V2 > V1) gives 1.

>=

The GREATER THAN or EQUAL TO Operator.

(V2 >= V1) gives 0.

IN

The IN Operator. If the value of the variable is equal to any one of the values in a given list of values, then it returns 1 else it returns 0.

V1 in (5,7,9,8) gives 1.

Example

DATA MYDATA1;
input @1 COL1 5.2	@7 COL2 4.1;
EQ_ = (COL1 = 11.21);
NEQ_= (COL1 ^= 11.21);
GT_ = (COL2 => 8);
LT_ = (COL2 <= 12);
IN_ = COL2 in( 6.2,5.3,12 );
datalines;
11.21 5.3
3.11  11.4
;
PROC PRINT DATA = MYDATA1;
RUN;

通过运行以上代码，我们得到以下输出。

On running the above code, we get the following output.

operators comparison

Minimum/Maximum Operators

下表对最小/最大运算符的详细信息进行了描述。这些运算符将变量的值在行中进行比较，并且从行中值的列表中返回最小值或最大值。

The below table describes the details of the Minimum/Maximum operators. These operators compare the values of the variables across a row and the minimum or maximum value from the list of values in the rows is returned.

Operator

Description

Example

MIN

The MIN Operator. It returns the minimum value form the list of values in the row.

MIN(45.2,11.6,15.41) gives 11.6

MAX

The MAX Operator. It returns the maximum value form the list of values in the row.

MAX(45.2,11.6,15.41) gives 45.2

Example

DATA MYDATA1;
input @1 COL1 5.2	@7 COL2 4.1 @12 COL3 6.3;
min_ = MIN(COL1 , COL2 , COL3);
max_ = MAX( COL1, COl2 , COL3);
datalines;
11.21 5.3 29.012
3.11  11.4 18.512
;
PROC PRINT DATA = MYDATA1;
RUN;

通过运行以上代码，我们得到以下输出。

On running the above code, we get the following output.

operators minmax

Concatenation Operator

下表描述了连接运算符的详细信息。该运算符连接两个或多个字符串值。它返回单个字符值。

The below table describes the details of the Concatenation operator. This operator concatenates two or more string values. A single character value is returned.

Operator

Description

Example

The concatenate Operator. It returns the concatenation of two or more values.

'Hello'

Example

DATA MYDATA1;
input  COL1 $	COL2 $  COL3 $;
concat_ = (COL1 || COL2 || COL3);
datalines;
Tutorial s point
simple easy learning
;
PROC PRINT DATA = MYDATA1;
RUN;

通过运行以上代码，我们得到以下输出。

On running the above code, we get the following output.

operators concate

Operators Precedence

运算符优先级指示复杂表达式中多个运算符的求值顺序。下表描述了一组运算符中的优先级顺序。

The operator precedence indicates the order of evaluation of the multiple operators present in complex expression. The below table describes the order of precedence with in a group of operators.

Group

Order

Symbols

Group I

Right to Left

** + - NOT MIN MAX

Group II

Left to Right

* /

Group III

Left to Right

+ -

Group IV

Left to Right

Group V