topic Re: Dynamic way of fetching Last 50 observations from dataset in SAS Programming

Dynamic way of fetching Last 50 observations from dataset

Flowerbud — Sun, 13 Oct 2024 16:01:10 GMT

Every time I am using proc contents to view total number of obervations in a dataset, then I am using dataset option to create secondary dataset of last 50 observations.
What is the pice of code to make my code dynamic for this everyday task.

Re: Dynamic way of fetching Last 50 observations from dataset

PaigeMiller — Sun, 13 Oct 2024 16:09:16 GMT

First find the number of observations in the data set, put it into a macro variable called NOBS.

https://communities.sas.com/t5/SAS-Communities-Library/Determining-the-number-of-observations-in-a-SAS-data-set/ta-p/475174

Then

data want;
     set have(firstobs=%eval(&nobs-49));
run;

Re: Dynamic way of fetching Last 50 observations from dataset

Bala_Saladi — Sun, 13 Oct 2024 16:08:11 GMT

Try this code:-

data second_dataset;
set sashelp.shoes nobs=the_count;
if _N_ > the_count -50;
run;

Re: Dynamic way of fetching Last 50 observations from dataset

Flowerbud — Sun, 13 Oct 2024 16:35:04 GMT

Thank you for your solution! I am new to SAS software, still learning advanced programming skills on macros.

Re: Dynamic way of fetching Last 50 observations from dataset

Tom — Sun, 13 Oct 2024 17:00:41 GMT

Note that FIRSTOBS= option expects an integer larger than 0.

So if you would need a little more logic to get it right.

Something like:

%let nobs=19;
%let n=10;
%let firstobs=%sysfunc(max(1,&nobs-&n+1));
%put &=nobs &=n &=firstobs;
data want;
  set sashelp.class(firstobs=&firstobs);
run;