topic Re: Extract "Day #" from a string of text in SAS Programming

Extract "Day #" from a string of text

mariko5797 — Wed, 20 Apr 2022 13:50:39 GMT

I want to make the days listed in the "Comments" column as it's own column. I would prefer each day to be it's own row.

Example: If COMMENTS = "No assessment made on Day 16, Day 17, Day 19" then I would extract DAYS = 16, 17, 19

Re: Extract "Day #" from a string of text

PaigeMiller — Wed, 20 Apr 2022 13:53:05 GMT

@mariko5797 wrote:

I want to make the days listed in the "Comments" column as it's own column. I would prefer each day to be it's own row.

Example: If COMMENTS = "No assessment made on Day 16, Day 17, Day 19" then I would extract DAYS = 16, 17, 19

Do you mean:

Example: If COMMENTS = "No assessment made on Day 16, Day 17, Day 19" then I would extract DAYS = 16 on one row, DAYS = 17 on another row, and DAYS= 19 on another row

Re: Extract "Day #" from a string of text

tarheel13 — Wed, 20 Apr 2022 15:44:08 GMT

so you want days to be a character variable with the days from comment variable? could you post some sample data as datelines and desired output?

Re: Extract "Day #" from a string of text

s_lassen — Fri, 22 Apr 2022 08:08:31 GMT

Something like this may work:

data want;
  set have;
  prxid=prxparse('/\bDay\s+\d+\b/i');
  start=1;
  end=length(comments);
  do until(0);
    call prxnext(prxid,start,end,comments,pos,len);
    if pos=0 then leave;
    day=input(scan(substr(comments,pos,len),2),8.0);
    output;
    end;
  drop start end pos len prxid;
run;

The PRX expression looks for a word boundary (\b), followed by "Day" and 1 or more whitespaces (blanks or tab characters) (\s+), 1 or more digits (\d+) and a word boundary again. The "i" at the end means to look for e.g. both "day", "DAY" and "Day".

If you want the DAY as a character variable, just drop the INPUT function (and perhaps declare the DAY variable with e.g "length day $8;" as it will otherwise get the same length as the COMMENTS variable).