topic Re: how to drop a series of variables in SAS in SAS Programming

how to drop a series of variables in SAS

Ken_oy — Thu, 16 Jan 2014 15:09:12 GMT

I want to drop/delete F1_flag, F2_flag, F3_flag, .... F99_flag from my dataset.

How can I do this efficiently? Thanks

Re: how to drop a series of variables in SAS

Linlin — Thu, 16 Jan 2014 15:14:24 GMT

if you don't have other varaibles staring with "f" you could use:

drop f:;

Re: how to drop a series of variables in SAS

Ken_oy — Thu, 16 Jan 2014 15:17:30 GMT

Yes, that is the problem. I do have F1, F2, ... in my dataset.

Re: how to drop a series of variables in SAS

Linlin — Thu, 16 Jan 2014 15:37:01 GMT

example:

data have;
input a1_flag a2_flag a3_flag a1 a2;
cards;
1 2 3 4 5
;
proc sql noprint;
select name into : dropped separated by ' '
from dictionary.columns
where libname='WORK' and memname='HAVE' and upcase(name) contains "FLAG";
quit;

data want;
set have;
drop &dropped;
proc print;run;

Re: how to drop a series of variables in SAS

kmoonmurr — Thu, 16 Jan 2014 16:32:33 GMT

If those flag variables were created in order, then you can delete with one simple statement:

drop F1_flag -- F99_flag;

To find out if they are in order, do

proc contents position ;

run;

Re: how to drop a series of variables in SAS

Linlin — Thu, 16 Jan 2014 18:57:00 GMT

have you tried your code?

Re: how to drop a series of variables in SAS

kmoonmurr — Thu, 16 Jan 2014 19:17:08 GMT

Yup. I do it all the time but I did create a simple data set before I sent this reply to you just to be sure. Works.

Re: how to drop a series of variables in SAS

Linlin — Thu, 16 Jan 2014 19:23:22 GMT

It doesn't work for me. please post your code and log file.

Re: how to drop a series of variables in SAS

art297 — Thu, 16 Jan 2014 20:30:56 GMT

Key_oy: One problem with Linlin's suggested code, which may or may not be an issue with your data, is that it will drop any variable that contains the string flag. E.g., in a data set like:

data have;

input a1_flag a2_flag a3_flag a1 a2 _flag_I_want;

cards;

1 2 3 4 5 6

;

it would also drop flag_I_want. The following is a way around that, namely just to drop variables that end with _flag:

proc sql noprint;

select name into : dropped separated by ' '

from dictionary.columns

where libname='WORK' and

memname='HAVE' and

reverse(upcase(trim(name))) like "GALF_%"

;

quit;

data want;

set have;

drop &dropped;

run;

Re: how to drop a series of variables in SAS

mikki — Fri, 17 Jan 2014 04:56:43 GMT

Hi Ken,

See the following code that drops only the variables starting with a and ending with flag. I updated Linlin's code with like and 'A%FLAG'.

quit;

data want;
set have;
drop &dropped;
proc print;run;

Re: how to drop a series of variables in SAS

kuridisanjeev — Fri, 17 Jan 2014 05:14:26 GMT

Hi,,

If your variable names are contiguous,then you can simply use like bellow...

Data test;

input f1 f2 f3 f4 f5 f6 n1 n2;

cards;

1 2 3 4 5 6 8 9

;

run;

Data yy;

set y;

drop f1-f6;

run;

Proc print;run;

Thanks & Regards,

Sanjeev.K

Re: how to drop a series of variables in SAS

deval — Sat, 25 Oct 2014 10:01:23 GMT

Hi,

If you drop the variables using drop option rather than drop statement, than it will be more efficient way.

data abc ;

set xyz (drop = &dropped.);

run;

Thanks,