topic firstobs obs not giving intended result? in SAS Programming

firstobs obs not giving intended result?

Nietzsche — Sat, 05 Nov 2022 11:09:29 GMT

Hi, on page 85 of the official SAS specialist prep guide, there is an example showing us how to use firstops and obs option in the proc print step that will override the system options.

There are only 20 observations in heart file. So when they use firstobs=20 obs=30, only one observation is produced, is that a typo because they said to produce the same output (6 observations) or am I misunderstanding the intention of the author?

heart.sas7dbat attached if you want to have a look at the file.

Re: firstobs obs not giving intended result?

fja — Sat, 05 Nov 2022 17:22:10 GMT

@Nietzsche wrote:

is that a typo because they said to produce the same output (6 observations) or am I misunderstanding the intention of the author?

IMHO it makes only sense the other way round. 20 and 30 in the options statement and 10 and 15 in the options of the data set. That would demonstrate that defaults are overwritten ... and came up with the same results as the previous code segment.

Just my 2ct

Fja

Re: firstobs obs not giving intended result?

Kurt_Bremser — Sat, 05 Nov 2022 11:32:43 GMT

Bad phrasing. It would have been better to put the 20/30 combination into the OPTIONS statement and then override that with the original 10/15.

Or make it clear that the result will be the same effect, but with a different outcome.

Re: firstobs obs not giving intended result?

Tom — Sat, 05 Nov 2022 14:48:21 GMT

They just left out explicitly showing all three combinations.

Re: firstobs obs not giving intended result?

Nietzsche — Sat, 05 Nov 2022 18:51:45 GMT

That's not bad just phrasing, it's bad logic/code.

Think the author was having a mental lapse went he wrote that code given he used the wrong library in the same code as well, hopefully SAS institute will put that into their official Errata (aka update)

Re: firstobs obs not giving intended result?

Tom — Sat, 05 Nov 2022 19:34:57 GMT

Seems very clear to me.

The point (as highlighted by the TIP) is that the dataset options OVERRIDE the system options.

The fact that the dataset referenced does not match the datasets in the course is a minor annoyance. (It is also an added learning opportunity. You need to build up you ability to translate example code to your situation).