topic Re: find number of times a word appears in a string without spaces in New SAS User

find number of times a word appears in a string without spaces

Billybob73 — Thu, 04 Apr 2019 10:21:22 GMT

I've found a number of solutions to count words within a string in SAS. However they all do not work for strings without spaces.

I have this string (it's in character format !) : 121121121121121

The string can also be like this : 121556121112141215

I would like SAS to return 5 in the first case and 4 in the second case. How do I do this ?

Many thanks !!!

Re: find number of times a word appears in a string without spaces

andreas_lds — Thu, 04 Apr 2019 10:27:42 GMT

If you don't have a delimiter in the string, you have to explain what "word" means in your problem.

Re: find number of times a word appears in a string without spaces

PeterClemmensen — Thu, 04 Apr 2019 11:15:53 GMT

Please elaborate why SAS should return 4 and 5 respectively.

Re: find number of times a word appears in a string without spaces

novinosrin — Thu, 04 Apr 2019 13:06:09 GMT

Hi @Billybob73

I am assuming you want a count of 2 in the string values which you haven't mentioned that @PeterClemmensen specifically asks.

If my assumption is correct-->

/*Creating sample data HAVE using your 2 string values*/
data have;
length str $20;
str='121121121121121';
output;
str='121556121112141215';
output;
run;
/*This assumes you want the count of 2 from what I see 5 and 4*/
data want;
set have;
want=countc(str,'2');
run;

Re: find number of times a word appears in a string without spaces

KachiM — Thu, 04 Apr 2019 14:31:45 GMT

My guess is that your pattern is '121' (PAT).

There are are several ways to skin the cat,

data have;
length str $18;
input str;
datalines;
121121121121121
121556121112141215
;
run;

data want;
   retain pat '121';
   lengpat = length(pat);
   set have;
   count = 0;
   k = 1;
   do while(1);
      k = find(str,'121',k);
      if k then count + 1;
      if k = 0 then leave;  
      k + lengpat;
   end;
keep str count;
run;

Another, much shorter way is to use difference of lengths of STR Before and End of compressing the pattern. Length function will return one for a null string. Therefore, lengthN is function is necessary after compression to catch the null string.

data need;
   set have;
   retain pat '121';
   lengpat = length(pat);
   lengB = length(str);
   temp = str;
   temp = compress(temp,'121');
   lengE = lengthn(temp);
   count = floor((lengB - lengE)/lengpat);
keep str count;
run;

Still a better way is have your own function. The advantage is that you can change the pattern as you like. It is coded once, compiled and saved to a Library of your choice.

proc fcmp outlib = work.cmput.lib;
   function patcount(str $, pat $);
   file log;
   patlen = length(pat);
   Blen = length(str);
   str = compress(str, pat);
   Elen = lengthn(str);
   rc = floor((Blen - Elen)/patlen);
   return(rc);
   endsub;
quit;

options cmplib = work.cmput; /* Like any other SAS Function.Found in */
                             /* this Library                         */

data fun;
   set have;
   pat = '123';
   count = patcount(str, pat);
drop pat;
run;

In case my guess is wrong, still the code will not change and you only need to change the PAT. Hope you will try this out.

Re: find number of times a word appears in a string without spaces

novinosrin — Thu, 04 Apr 2019 14:55:35 GMT

I think you read the pattern well:) Nicely done!

Re: find number of times a word appears in a string without spaces

novinosrin — Thu, 04 Apr 2019 14:59:12 GMT

data have;
length str $18;
input str;
datalines;
121121121121121
121556121112141215
;
run;

data want;
set have;
count=count(str,'121');
run;

Re: find number of times a word appears in a string without spaces

KachiM — Thu, 04 Apr 2019 15:34:29 GMT

NOvinosrin:

Count() function is a very good choice.

Re: find number of times a word appears in a string without spaces

Billybob73 — Fri, 19 Apr 2019 07:54:59 GMT

Great stuff!! Thanks very much