How to add and delete observations within a range

[Therain]

Hi,

I use SAS 9.4 and I have a dataset with a variable called "mdd", which has 1870 observations. I hope to get a descriptive statistics of mdd with 2010 observations (observation 1871-2010 will be assigned values of 0). I used the following code:

PROC UNIVARIATE DATA=have;
VAR mdd;
RUN; 

But it only offers info about the 1870 observations.

So I used the following codes to add rows:

proc sql;
insert into have
set mdd=0
set mdd=0
...
set mdd=0;

This is troublesome and I add observations to 2019 by accident. Now I want to delete the observations from 2011-2019 but I do not know how to do that. So is there a code to directly add  mdd=0 from observation 1871 to 2010? Also, is there a code to delete observations in a range?

Thanks!

[PGStats · Accepted solution]

Looks like all you need to do is extend a dataset with blank observations. You could use something like this:

data want;
set have end=done;
output;
if done then do;
	mdd = 0;
	do i = 1871 to 2010; output; end;
	end;
drop i;
run;
	

(untested)

[Therain]

Thank you! It works!

[Doc_Duke]

As you have learned the hard way, it is good not to modify the original data.  Now that you have done it, deleting the extra observations is a simple data step:

DATA haveless;

SET have;

IF _n_>2010 THEN DELETE;  *Assumes added rows at the end;

RUN;

If you still have the original data, a better approach to augmentation might be:

DATA havemdd0;

DO _I_ =1871 to 2010;

  mdd=0;

  OUTPUT;

  END;

DROP _i_;

RUN;

DATA have2;

SET have havemdd0;

RUN;