topic Re: Subtraction function in SAS Programming

Subtraction function

Paul_NYS — Mon, 26 Nov 2012 20:14:13 GMT

I have used the sum function in a data step to add the value of a previous row to a current one. I was wondering if there is something similar for subtracting a value in a previous row from a value in the current data set? I did not see anything for 'subtract' and tried adding a negative value using the sum function but that did not work either:

data s1AgeCleanCare1;

set s1AgeCleanSort1;

by cnty_name startyear agecat4 exitMonthCategory;

if first.agecat4 then CumulativeNumber=OutOfHomeCare;

OutOfHomeCare + (-CumulativeNumber);

run;

Paul

Re: Subtraction function

ballardw — Mon, 26 Nov 2012 20:19:01 GMT

The DIF (var) function, similar to LAG in concept, will give the difference from the previous record and the current or up to 99 records for a variable depending on DIF, DIF2, ..., DIF99. However you don't want to use it after IF statements as you will likely get unexpected results.

Re: Subtraction function

art297 — Mon, 26 Nov 2012 20:19:24 GMT

Couldn't you just use sum(OutOfHomeCare-CumulativeNumber);

It is documented at: http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a000245953.htm

Re: Subtraction function

Paul_NYS — Mon, 26 Nov 2012 22:00:38 GMT

Yes, I did the sum() above and that worked for me, but I think the DIF would work as well. Thank you both.

Paul

Re: Subtraction function

art297 — Mon, 26 Nov 2012 22:09:16 GMT

Paul, Depends upon what you need. I didn't even see the part of your post concerning previous record. Since the sum function retains a value across records, it could be used to start with a value and then subtract a current record's value from it. The dif function would just get the difference between the current and previous record.

Re: Subtraction function

Paul_NYS — Mon, 26 Nov 2012 22:27:38 GMT

Thats all I need in this particular situation actually: current - previous.

Paul

Re: Subtraction function

Ksharp — Wed, 28 Nov 2012 04:07:52 GMT

and take a look at function range();

data _null_;
a=4; b=1;
x=range(a,b);
put x=;
run;

Ksharp