topic Re: Identify the true if-substatement in SAS Programming

Identify the true if-substatement

Emjay — Mon, 27 Aug 2018 12:35:09 GMT

Let's say I have the following:

data have;
input time count rate1 rate2 settings;
cards;
0.65 3 1.2 0.5 7
2.25 5 0.7 0.7 2
7 4 0.8 0.8 3
7 4 0.8 0.8 6
;
run;

Now I have the following rule for state '99':

data almost_want;
set have;
if 
(time<=1 and (
	(count>=1)
))
or
(1<time<=3 and (
	(count>=2 and rate1>0.55 and rate2>0.4)
))
or
(3<time and (
	(settings<=4 and count>=2 and rate1>0.55 and rate2>0.4)
	or
	(settings>=5 and count>=3 and rate1>0.55 and rate2>0.4)
))
then State=99;
run;

But what I actually want is this:

data want;
input time count rate1 rate2 settings State reason;
cards;
0.65 3 1.2 0.5 7 99 1
2.25 5 0.7 0.7 2 99 2
7 4 0.8 0.8 3 99 3
7 4 0.8 0.8 6 99 4
;
run;

So not only '99' but also because of which condition it is '99'.

In this example I have only one state cause it's enough to describe my problem but in the 'real' data it's five states with up to seven substatements per state.

Is there a way to find out which substatement of my if-condition was true?

So something like:

data almost_want;
set have;
if 
(time<=1 and (
	(count>=1)
	then reason=1
))
or
(1<time<=3 and (
	(count>=2 and rate1>0.55 and rate2>0.4)
	then reason=2
))
or
(3<time and (
	(settings<=4 and count>=2 and rate1>0.55 and rate2>0.4)
	then reason=3
	or
	(settings>=5 and count>=3 and rate1>0.55 and rate2>0.4)
	then reason=4
))
then State=99;
run;

Re: Identify the true if-substatement

Astounding — Mon, 27 Aug 2018 12:44:18 GMT

Don't try to do it all in one statement.

if time <= 1 and count=1 then do;
   reason=1;
   state=99;
end;
else if (1 < time <= 3) and (count > 2 and rate1 > 0.55 and rate2 > 0.4) then do;
   reason=2;
   state=99;
end;
else .... similarly for other reasons

Using a few statements makes it easy.

Re: Identify the true if-substatement

Emjay — Mon, 27 Aug 2018 12:47:22 GMT

Well, of course I could break it down in one if-statenment for every reason but I was hoping for an all-in-one-way...

Re: Identify the true if-substatement

ballardw — Mon, 27 Aug 2018 15:16:24 GMT

@Emjay wrote:

Well, of course I could break it down in one if-statenment for every reason but I was hoping for an all-in-one-way...

Since you couldn't provide a rule in a very concise manner in English that is often a clue that the code will not be brief either. Five variables, a different set for each time interval value, a mix of combinations of values I would find a very unlikely candidate for "all-in-one-way" code whatever that might be.

BTW, you want to be aware that < or <= (or LT and LE) conditions are true when a value is missing. If you do not want the evaluation

Re: Identify the true if-substatement

Emjay — Tue, 28 Aug 2018 06:45:42 GMT

Yes, the conditions are a little nested, but that's unfortunately as it is.

With all-in-one I wasn't necessarily hoping for super short code, but maybe for a way to mark the true if-condition without writing a if-statement for every single one. I thought SAS maybe provides such a functionality...

But thanks for the hint with the < and missing values. Luckily I don't have those.