topic Re: How do I vertically change value to the one above? in SAS Programming

How do I vertically change value to the one above?

niki0209 — Wed, 26 Jan 2022 15:47:57 GMT

Hello,

I am looking to change values of observations that satisfy a specific condition to the values "above".
My data looks somewhat like this:

var1 var2
1 A
1 A
1 A
0 X
1 A
1 A
2 B
2 B
0 X
2 B
2 B
3 C
3 C
3 C
0 X

In this example I would like to change the value of var2 to the value of the observation above, only if the value of var1 is equal to 0.

In the example above, the result would be:

var1 var2
1 A
1 A
1 A
0 A
1 A
1 A
2 B
2 B
0 B
2 B
2 B
3 C
3 C
3 C
0 C

I hope someone can help me. Thanks alot!

Re: How do I vertically change value to the one above?

novinosrin — Wed, 26 Jan 2022 16:10:18 GMT



data have;
input var1 var2 $;
cards;
1 A
1 A
1 A
0 X
1 A
1 A
2 B
2 B
0 X
2 B
2 B
3 C
3 C
3 C
0 X
;

data want;
 set have;
 k=lag(var2);
 if var1=0 then var2=k;
 drop k;
run;

Re: How do I vertically change value to the one above?

Reeza — Wed, 26 Jan 2022 16:10:53 GMT

data want;
set have;

prev_var2 = lag(var2);

if var1=0 then var2=prev_var2;

run;

@niki0209 wrote:

Hello,

I am looking to change values of observations that satisfy a specific condition to the values "above".
My data looks somewhat like this:

var1 var2
1 A
1 A
1 A
0 X
1 A
1 A
2 B
2 B
0 X
2 B
2 B
3 C
3 C
3 C
0 X

In this example I would like to change the value of var2 to the value of the observation above, only if the value of var1 is equal to 0.

In the example above, the result would be:

var1 var2
1 A
1 A
1 A
0 A
1 A
1 A
2 B
2 B
0 B
2 B
2 B
3 C
3 C
3 C
0 C

I hope someone can help me. Thanks alot!

Re: How do I vertically change value to the one above?

Amir — Wed, 26 Jan 2022 17:09:11 GMT

Hi @niki0209,

How about:

data want;
   set have;
   var2 = ifc(var1,var2,lag(var2));
run;

Kind regards,

Amir.