topic How to extract observations containing a specific word + debugging in data step in SAS Programming

How to extract observations containing a specific word + debugging in data step

sadovsd — Mon, 17 Jul 2023 18:00:43 GMT

My goal is to extract all observations with an item_name that matches the value of the macro variable expense_type, from a dataset like the one below

Right now, my solution is only extracting those observations that start with that word:

observations like the one below, which include that word in a different position are not included

I've been trying to debug to figure out what the current word is in the loop iteration, but I keep getting errors.put 'current_word: ' scan(item_name, n); isn't working. How can I even debug in this case? this is my code:

/* find observations with item_codes corresponding to the specific expense type keyword user wants */
data item_docs_specific;
    set item_docs;
    %LET expense_type = "&expense_type";
    /* loop through item_name variable to find observations that match with the expense type keyword use.r wanted */

    do n=1 to countw(item_name);		
        put 'item_name:' item_name;
        /* put 'current word #': n; */
        /* put 'current_word: ' scan(item_name, n); */
        /* put 'expense_type:' &expense_type; */
    
        if count(lowcase(scan(item_name,n)), lowcase(&expense_type)) > 0;
        output;        
    end;
    drop n;
run;

Re: How to extract observations containing a specific word + debugging in data step

Quentin — Mon, 17 Jul 2023 18:43:42 GMT

Hi,

To debug this, I would recommend running code like the following. I created a variable WORD, for the nth wort of the string, and commented out your IF statement:

%LET expense_type = "Care";
data item_docs ;
  input item_name  $16. ;
  cards ;
Care of invalids
Something else
Personal care
run ;


data item_docs_specific;
    set item_docs;   
    /* loop through item_name variable to find observations that match with the expense type keyword use.r wanted */

    do n=1 to countw(item_name);		
        word=scan(item_name, n) ;
        put item_name= n= word= ;
   
        *** if count(lowcase(scan(item_name,n)), lowcase(&expense_type)) > 0 ;
        output;        
    end;
    drop n;
run;

If that is working like you want, then uncomment the IF statement and see how it changes. The IF statement here is your problem. Note that it is a subsetting IF statement.

You don't have to loop through the list to do this. You can use the FINDW function to search for a word like:

data item_docs_specific;
  set item_docs;   
  if findw(item_name,&expense_type,' ',"i") ;
run ;

But since you've already written the loop, it's worth debugging your current code, just to think through debugging a loop, and the implications of using a subsetting IF statement inside a loop.