topic delete blank columns in SAS Programming

delete blank columns

milts — Wed, 10 Jun 2009 07:36:43 GMT

hello

i have a data set containing columns x y z. data set contains 10 records. i want to check if x has a value for each observation. however if all 10 records have a value of missing or 0 in x, i want to delete the column x. how can i do that?

thanks!

Re: delete blank columns

deleted_user — Wed, 10 Jun 2009 10:30:53 GMT

Hi,

For this we need to run PROC MEANS with (N NMISS MIN MAX) on the data first to identify those variables having missing values or zero's.
After this we can drop those variables whose N=NMISS or (MIN=0 and MAX=0) by using DROP or KEEP.

Hope this will help you

Re: delete blank columns

advoss — Thu, 11 Jun 2009 17:10:44 GMT

if you are generating this table in a data step, you could create a retained variable to count the number of time that x is missing and then on the last observation, compare that variable with _n_ and if they are equal conditionally execute a data step to drop that variable...like:
data xyz;
set abc(keep=x y z) end=lastone;
retain x_missing 0;
x_missing = x_missing + missing(x);
if lastone then do;
if x_missing = _n_ then call execute('data def;set xyz(keep=y z);run;');
end;
run;

Re: delete blank columns

milts — Sun, 14 Jun 2009 23:51:13 GMT

i see. thanks a lot for the help !

Re: delete blank columns

deleted_user — Mon, 15 Jun 2009 06:01:06 GMT

Try this

data d1;
set s1;
if x=y=z then flag='v';
run;

data d2;
set d1;
if flag ne 'v' then delete;
run;