topic Re: Create a loop with multiple conditions in SAS Programming

Create a loop with multiple conditions

Vic6 — Wed, 09 Jun 2021 09:32:21 GMT

Hi guys,

I am trying to create a continuous loop that will meet the following conditions:

- identify first value>= 4;

- if value>=4 then skip the next 2 records (not relevant for my analysis) and starting from record no 3, count next 5 records; after 5 records add a fixed numeric value (3.14);

- if while counting the 5 records in scope you will find another value>=5 then stop counting, add a fixed numeric value (1.03) and start again from the beginning.

Could you help me find a solution? Please find below an example of the expected result.

Thank you!

Variable	New_column_with_numeric_value	Counter	Explanations
1	.	0
5	.	0	variable >=5 identified;START
2	.	0	skipp first 2 records
3	.	0	skipp first 2 records
1	.	1	start counting
6	1.03	0	add value for counter<5, reset counter and start againg
1	.	0	skipp first 2 records
3	.	0	skipp first 2 records
2	.	1	start counting
1	.	2
3	.	3
3	.	4
1	3.14	5	counter=5 then 3.14; STOP
1	.	0	wait for next variable>=5
2	.	0	wait for next variable>=5
6	.	0	variable >=5 identified;START
1	.	0	skipp first 2 records
2	.	0	skipp first 2 records
3	.	1	start counting
1		2
1		3
1		4
2	3.14	5	counter=5 then 3.14; STOP

Re: Create a loop with multiple conditions

FreelanceReinh — Wed, 09 Jun 2021 11:59:16 GMT

Hi @Vic6 and welcome to the SAS Support Communities!

Is the change of criteria from "value>=4" in item 1 and 2 to "value>=5" in item 3 and "variable >=5" in column "Explanations" really part of the rules or just a typo? I assumed the latter and used the threshold 5 consistently. For the test data it doesn't matter anyway (as value 4 doesn't occur).

/* Create test data for demonstration */

data have;
input Variable	@@;
cards;
1 5 2 3 1 6 1 3 2 1 3 3 1 1 2 6 1 2 3 1 1 1 2
;

/* Create variables New and Counter */

data want(drop=_:);
set have;
if variable>=5 then
  if _s then do;
    New=1.03;
    _c=0;
  end;
  else _s=1;
if _s then _c+1;
Counter=max(0,_c-3);
if Counter=5 then do;
  New=3.14;
  _s=0;
  _c=0;
end;
retain _s;
run;

Re: Create a loop with multiple conditions

Vic6 — Fri, 25 Jun 2021 15:15:25 GMT

Many thanks! It works great!

Re: Create a loop with multiple conditions

Vic6 — Mon, 05 Jul 2021 11:45:07 GMT

One more question. What if I want to skip the first 2 records (from the example above) even if the value =>5? The idea is that the first 2 records are irrelevant regardless the value.

Re: Create a loop with multiple conditions

FreelanceReinh — Mon, 05 Jul 2021 11:59:49 GMT

You can extend the first IF-THEN statement as follows to ignore values >=5 in the first two records:

if _n_>2 & variable>=5 then