topic Extract last n obs from datasets in SAS Programming

Extract last n obs from datasets

BrahmanandaRao — Wed, 23 Dec 2020 10:17:35 GMT

Hi Guys

I have huge datasets in a library so i want extract last 5 observations for each dataset in a library

Re: Extract last n obs from datasets

PeterClemmensen — Wed, 23 Dec 2020 10:25:41 GMT

And what do you want to do with those 5 obervations?

Re: Extract last n obs from datasets

Kurt_Bremser — Wed, 23 Dec 2020 10:29:12 GMT

See here: https://communities.sas.com/t5/SAS-Programming/last-three-obs/m-p/599976 and here: https://communities.sas.com/t5/SAS-Programming/multiple-table-extract-last-obs/m-p/616552

All found in your own(!) questions.

Re: Extract last n obs from datasets

singhsahab — Wed, 23 Dec 2020 12:37:51 GMT

proc sql;
select count(*) into :co from dictionary.tables where libname like 'yrlibname';
select memname into :data1 - :data%left(%trim(&co)) from dictionary.tables where libname like 'yrlibname';
quit;

%macro data_extract;
%do i=1 %to &co;
data &&data&i;
set yrlibname.&&data&i nobs=nobs;
if _n_ > nobs - 5;
run;
%end;
%mend;

%data_extract;

Re: Extract last n obs from datasets

Kurt_Bremser — Wed, 23 Dec 2020 13:58:54 GMT

@singhsahab with large datasets, you should use the POINT option:

data &&data&i;
do pt = nobs - 4 to nobs;
  set yrlibname.&&data&i nobs=nobs point=pt;
  output;
end;
stop;
run;

as that avoids reading the whole dataset.