topic Re: Writing special character star "*" for blank or missing. in SAS Programming

Writing special character star "*" for blank or missing.

geneshackman — Tue, 28 Feb 2023 13:57:19 GMT

Hi all. I hope everyone is healthy.

Hopefully a very simple question. How to write * when the data are blank or have "."?

I have this code

if tbr2="." then tbr2="*";
if tpr2="." then tpr2="*";

I -think- the data set has "." as values that mean blank or missing, but that could be the problem too.

So, first question: would that code work, if the values are "."?

Thanks

Re: Writing special character star "*" for blank or missing.

yabwon — Tue, 28 Feb 2023 14:10:02 GMT

1) If you variable is numeric you won't be able to replace it with "*", in this case you could only write a format that displays missing value as asterisk, something like:

proc format;
value missinAsterisk
  low-high = [best32.]
  other = "*"
  ;
run;

data _null_;
  do i = -1,100,3.14,.,.A,.Z,._,-17,42;
    put i missinAsterisk.;
  end;
run;

2) If you have character variable then the condition:

var = " "

checks if the variable is blank (missing). In this case you can do it:

if tbr2=" " then tbr2="*";

3) If your variable is character and contains "."(dot) then it is not missing 🙂 but... if you want to replace all dots in your variable you could try to use translate() function:

data _null_;
  do x = "...", ".", "  .", ". .";
     y = translate(x,"*",".");
     put x= / y=;
  end;
run;

Bart

Re: Writing special character star "*" for blank or missing.

geneshackman — Tue, 28 Feb 2023 14:15:55 GMT

Hi Bart. Good point. I checked. The variable is character, so I'll try some of your solutions. Thanks.

Re: Writing special character star "*" for blank or missing.

Quentin — Tue, 28 Feb 2023 14:58:10 GMT

If it's character, and '.' means missing, I think it's better to convert to a character misssing (blank) rather than to an asterisk. If it's a character missing, then SAS knows that is missing. If it's a *, then you as the programmer need to remember that * means missing and code around it. I like the format approach that Bart showed. It allows you to keep the value as missing, but display it as an asterisk, e.g.:

data have ;
  do x = "A","B"," ",".","D";
    output ;
  end;
run ;

proc format;
  value $ missinAsterisk 
    ' '='*'
    other = [$char8.]
  ;
run;

data want ;
  set have ;
  array chars {*} _character_ ;
  do i=1 to dim(chars) ;
    if chars{i}='.' then call missing(chars{i}) ;
  end ;
  drop i ;

  format _character_ $missinAsterisk. ;
run ;

proc print data=want ;
run ;

Re: Writing special character star "*" for blank or missing.

geneshackman — Tue, 28 Feb 2023 15:09:43 GMT

Thanks Bart and Quentin. I examined the data set once more, because of your responses, and it turns out the problem was that the value wasn't "." but " .". It had spaces in front of the period. I put in the spaces, and that worked.

if tbr2=" ." then tbr2="*";
if tpr2=" ." then tpr2="*";

Thanks again, and I apologize for not examining the data more closely in the first place. Who would have thought!

Gene