[求助] sas 中 input @与@@ 的区别是什么

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

<br/>各位大侠，sas 中 input 变量1   变量2  @ 与 @@ 有什么区别？output时会有什么不同，万分谢谢<br/>

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：Input put output outpu 各位大侠

lz,你将两者在SAS上运行一下，区别不就出来了吗？比如：第一次运行 input x1 x2 @;第二次运行 input x1 x2 @@;这样一比较，二者的不同不就一目了然了吗？

One @ sign means conditional input. That is, the data record from the raw data will be saved in the input buffer and will not be saved to the corresponding variable. Only when the second "input" statement is encountered can the raw data be read into the SAS data set.

For double @@, sometimes each line of the raw data is longer than the size of SAS input variables, and the input will only stop once the end of line is encountered in the raw data set. For example,

data example
    input group $ score @@;
    datalines;
    1 100 1 200 1 300
    2 120 2 210 2 320
    3 310 3 420 3 540;
run;

proc print;
run;

In the example above you need to use double trailing @@ sign since each row of the embedded data has three observations

The output of the example looks like:

ob     group    score
1         1         100
2         1         200
3         1         300
4         2         120
5         2         210
6         2         320
7         3         310
8         3         420
9         3         540

谢谢了

多谢！！！！

可以解释下下面的@是什么作用吗？


data NYC;
input city $ 18-32 @;
if city='New York';
input FLNO 1-4 AirLine $6-18 city $ 18-32 Time $34-40;
cards;
9238 American      New York       10:00
4235 United          Philadelphia    5:00pm
798   Delta            New York       8:50
4824 North West   Houston         12:30pm
1639 South West  Chicago          4:15pm
5417 North West   New York       11:25
;
run;
Proc print data=NYC;
title 'Flight to New York City';
run;



3# liugxhk

是不是换行的意思?
其实实践中很少用到 因为数据已经是有的

the new data set will only take records which have City = "New York" and discard the rest.  @ means the program will put the input process on hold to make the conditional assessment.

1 2
3 4

input a@;
input b;

hold current record for input
a=1 b=2

input a
input b
a=1 b=3

the difference is how long they hold a line of data for input. The trailing @ holds a line of data for subsequent INPUT statements, but releases that line of data when SAS returns to the top of the DATA step to begin building the next observation. The double trailing @ holds a line of data for subsequent INPUT statements even when SAS starts building a new observation. In both cases, the line of data is released if SAS
reaches a subsequent INPUT statement that does not contain a line-hold specifier.