topic Re: Blank Values in SAS Programming

Blank Values

endofline — Tue, 15 Dec 2015 23:11:05 GMT

I have a question on how to work with variables with blank values. I recently imported in a dataset using the SAS import wizard. When I brought it in, I have a variable that has some missing values. When it brought the dataset in, insteading of assigning those values as a '.' they're blank instead. I'm trying to use that to exclude those cases, however, it isn't working since the values are blank. Any insight would be appreciated!

Re: Blank Values

Astounding — Tue, 15 Dec 2015 23:35:35 GMT

When character strings are blank, refer to them as a blank within quotes:

if variable=' ' then delete;

Good luck.

Re: Blank Values

Reeza — Tue, 15 Dec 2015 23:35:48 GMT

Character variables denote missing as 'blank values'.
Numeric variables denote missing as '.'.

Use can use the missing()/nmiss/cmiss functions to determine a missing value.

For example
if missing(var) then do ...;

Re: Blank Values

FreelanceReinh — Tue, 15 Dec 2015 23:38:58 GMT

I assume that it is a character variable, not a numeric variable. Indeed, missing values of character variables are stored as single blanks, not periods. To exclude observations with missing values for that variable you could use a WHERE or IF contition of the form varname ne ' ' or, more generally (suitable also for numeric variables), not missing(varname).

Example:

data have;
length c $8;
input c;
cards;
abc
.
def
; /* Please note that the period in the raw data indicates the missing value although C is character! */

data want;
set have;
where not missing(c);
run;

Re: Blank Values

nketata — Fri, 10 Mar 2017 19:01:00 GMT

To check if a cell is empty, do not do

if var='';

use the function anyalnum :

if anyalnum(substr(strip(var),1,1)) = 0 then A="empty____"

if anyalnum(substr(strip(var),1,1)) ne 0 then A="not empty"

Re: Blank Values

mkeintz — Fri, 10 Mar 2017 19:03:14 GMT

Tell us why you make that suggestion.

Re: Blank Values

nketata — Fri, 10 Mar 2017 19:15:49 GMT

I imported a file from Excel using the command

libname go pcfiles path = C:\temp\myfile.xlsx' textsize = 32767;

data nicefile ;

set go.'Sheet1$'n;

if _N_=1 then call execute ('proc sort data=nicefile; by var1; run;'); run;

libname go clear;

and I had a process based on missing values in a character variables.

Some cells looked empty but they where not, so my condition if var1='' was sometimes not valid.

Hence the use of the function

if anyalnum(substr(strip(var1),1,1)) ne 0

to make sure var1 starts with a letter or a number.

Re: Blank Values

mkeintz — Fri, 10 Mar 2017 22:11:42 GMT

I think your advice is useful for eliminating all cells that don't contain numbers or letters, but I'm uncomfortable designating it as a way to see "if a cell is empty". I would not term a cell with non-printable characters as "empty", even if it is unwanted.

data _null_;

x='09'x;

put x= ; /* X looks like a true blank */

put x=hex2.; /* but printed in hex, we see it is not a hex 20 (e.g. a true blank) */

run;