[求助]请教Base SAS题目（4.01）

是 否 +2 论坛币

k人 参与回答

经管之家送您一份

应届毕业生专属福利!

求职就业群

赵安豆老师微信：zhaoandou666

经管之家联合CDA

送您一个全额奖学金名额~ !

立即领取

感谢您参与论坛问题回答

经管之家送您两个论坛币！

+2 论坛币

A SAS PRINT procedure output of the WORK.LEVELS data set is listed below:

Obsname level

1 Frank 1

2 Joan 2

3 Sui 2

4 Jose 3

5 Burt 4

6 Kelly .

7 Juan 1

The following SAS program is submitted:

data work . expertise;

set work. levels;

if level = . then

expertise = 'Unknown';

else if level = 1 then

expertise = 'Low';

else if level = 2 or 3 then

expertise =' Medium';

else

expertise = 'High';

run;

Which of the following values does the variable EXPERTISE contain?

A. Low, Medium, and High only

B. Low, Medium, and Unknown only

C. Low, Medium, High, and Unknown only

D. Low, Medium, High, Unknown, and ' ' (missing character value)

Answer: B .为什么没有High？

扫码加我 拉你入群

请注明：姓名-公司-职位

以便审核进群资格，未注明则拒绝

分享0 收藏2 回帖

关键词：Base following Procedure Character Variable 题目 SAS Base

找了半天,终于弄明白了,这个问题还是很能迷惑人的.

在sas中关于or是这样说明的:

Remember that only one comparison in a series of OR comparisons must be true to make a condition true, and any nonzero, nonmissing constant is always evaluated as true (see Boolean Numeric Expressions). Therefore, the following subsetting IF statement is always true:

if x=1 or 2;

SAS first evaluates X=1, and the result can be either true or false; however, since the 2 is evaluated as nonzero and nonmissing (true), the entire expression is true.

因为后面2是一个常数且不为0,所以整个表达式都为真,那么后面都执行同样的操作.

所以如果你的题目想要包含"high",那么应该改为:

~~~

else if level = 2 or level=3 then

expertise =' Medium';

~~~~~~~~~~

依次类推，凡是用Or来连接的这种形式，else 后面的值一律取不到，是吧？

The following SAS program is submitted:

data test;

set sasuser.employees;

if 2 le years_service le 10 then

amount=1000;

else if years_service gt 10 then

amount=2000;

else

amount=0;

amount_per_year=years_serice/amount;

run;

Which one of the following values does the variable AMOUNT_PER_YEAR contain

if an employee has been with the company for one year?

A. 0

B. 1000

C. 2000

D. . (missing numeric value)

Answer: D.

这道题是不是因为amount=0, 所以整个值才是missing numeric value?

Yes. You are right. 0 不能作分母， 所以商是missing.

The contents of the raw data file SIZE are listed below:

----|----10---|----20---|----30

72 95

The following SAS program is submitted:

data test;

in file 'size';

input@ 1 height 2.@ 4 weight 2;

run;

Which one of the following is the value of the variable WEIGHT in the output data set?

A. 2

B. 72

C. 95

D. . (missing numeric value)

Answer:A
I know the problem is to omit the period.SAS assign a length of 2 to weight instead of reading weight with the 2 informat.
I would like to ask why the value of the variable WEIGHT is 2?

When omitting the dot after the 2, sas ignore the trailing sign and the number, in this case , it is @4.

So SAS consider the "2" without the dot as column not the 2 digits of the weight. so it reads the second column number, which is 2. so if substituting the 2 with 3, you get missing value, which is dot, sub 2 with 4, you get 9 and so on.