BookmarkSubscribeRSS Feed

How to find all connected components in a graph

Started ‎10-25-2015 by
Modified ‎01-18-2017 by
Views 6,530

proc optnet is the ideal tool for finding connected components in a graph, but it requires the SAS/OR licence. Connected components (or subgraphs) can also be found using this SubGraphs macro, which uses just Base SAS.

 

See attached SAS program file.

Comments

Here is my code. If somebody need it .

 


data have;
infile cards ;
input from $  to $ ;
cards;
1     2
1     3
4     5
5     2
9     4
6     7
8     7
;
run;
data full;
  set have end=last;
  if _n_ eq 1 then do;
   declare hash h();
    h.definekey('node');
     h.definedata('node');
     h.definedone();
  end;
  output;
  node=from; h.replace();
  from=to; to=node;
  output;
  node=from; h.replace();
  if last then h.output(dataset:'node');
  drop node;
run;


data want(keep=node household);
declare hash ha(ordered:'a');
declare hiter hi('ha');
ha.definekey('count');
ha.definedata('last');
ha.definedone();
declare hash _ha(hashexp: 20);
_ha.definekey('key');
_ha.definedone();

if 0 then set full;
declare hash from_to(dataset:'full(where=(from is not missing and to is not missing))',hashexp:20,multidata:'y');
 from_to.definekey('from');
 from_to.definedata('to');
 from_to.definedone();

if 0 then set node;
declare hash no(dataset:'node');
declare hiter hi_no('no');
 no.definekey('node');
 no.definedata('node');
 no.definedone();
 

do while(hi_no.next()=0);
 household+1; output;
 count=1;
 key=node;_ha.add();
 last=node;ha.add();
 rc=hi.first();
 do while(rc=0);
   from=last;rx=from_to.find();
   do while(rx=0);
     key=to;ry=_ha.check();
      if ry ne 0 then do;
       node=to;output;rr=no.remove(key:node);
       key=to;_ha.add();
       count+1;
       last=to;ha.add();
      end;
      rx=from_to.find_next();
   end;
   rc=hi.next();
end;
ha.clear();_ha.clear();
end;
stop;
run;
Version history
Last update:
‎01-18-2017 10:52 PM
Updated by:
Contributors

hackathon24-white-horiz.png

The 2025 SAS Hackathon Kicks Off on June 11!

Watch the live Hackathon Kickoff to get all the essential information about the SAS Hackathon—including how to join, how to participate, and expert tips for success.

YouTube LinkedIn

SAS AI and Machine Learning Courses

The rapid growth of AI technologies is driving an AI skills gap and demand for AI talent. Ready to grow your AI literacy? SAS offers free ways to get started for beginners, business leaders, and analytics professionals of all skill levels. Your future self will thank you.

Get started

Article Tags