topic Re: Change observations according to the previous obervation value in SAS Procedures

Change observations according to the previous obervation value

Dingdang — Fri, 30 Jan 2015 16:46:30 GMT

Hi,

I have a dataset which looks like:

data have;

infile datalines;

input numbers;

datalines;

;

In case the previous obervation is not . and the present observation equals to the previous value, then i would like to set the current value to . So what I would like to have is

data want;

infile datalines;

input numbers;

datalines;

;

Can someone help me solve this problem? Many thanks in advance!

BR Dingdang

Re: Change observations according to the previous obervation value

Haikuo — Fri, 30 Jan 2015 16:54:28 GMT

lag() or dif();

data have;

infile datalines;

input numbers;

datalines;

;

data want;

set have;

if dif(numbers)=0 then

numbers=.;

run;

Re: Change observations according to the previous obervation value

Ksharp — Sat, 31 Jan 2015 11:52:05 GMT

data have;
     infile datalines;
     input numbers;
     datalines;
1
1
.
2
3
4
.
5
5
6
7
7
;
run;
data want;
 set have;
 by numbers notsorted;
 if not first.numbers then numbers=.;
 run;

 data want1;
 set have;
 by numbers notsorted;
 if numbers=lag(numbers) then numbers=.;
 run;

Xia Keshan