BASUG August Webinar on hashing

[Quentin]

Hi All,

BASUG is hosting a free webinar in August on hashing.  But rather than simply post the description, I took a shot at a little example of using a hash table to decipher a message.  If you run the below code and check the log, hopefully you'll see readable text with registration info.  Hopefully. (If it doesn't work, please  let me know : )

Trust me, if you're interested in learning more about hashing, you don't want to miss this!

*Build the lookup table to decipher the message ;

data chars (keep=char rand);
  call streaminit(12345); 
  length chars $95;
  chars = collate(32,127);
  do i=1 to length(chars) ;
    char=substrn(chars,i,1) ;
    rand=rand("Uniform") ;
    output ;
  end ;
run;

proc sort data=chars ;
  by rand ;
run ;

data cipher ;
  set chars (keep=char);
  code=put(_n_,z2.) ;
run ;

*Read the message,
 read lookup table into a hash table, 
 and use to decipher the message
;

data _null_ ;
  if 0 then set cipher ;

  if _n_=1 then do ;
    declare hash h(dataset:"cipher") ;
    h.definekey("code") ;
    h.definedata("char") ;
    h.defineDone() ;
  end ;

  infile cards missover;
  do i=1 to 100 ;
    input code $2. @;
    if not missing(code) then do ;
      h.find(key:code) ;
      put char +(-1) @ ;
    end ;
  end ;
  put ;
  
  cards ;
374429261830144549713570459271936149082445926154544569710870882471452944294524091627451470082445128814144559083471242313
128814144592615454454824711471497045474449454449612208707138451888613871457009452944294573081452614905464575240922450409882445756124147045730814524570094573081452450969457308145271144713
427138497114380823194544880588147045100645631046070785634677074536264390856583
4352714592719361490824456114457512787819459388704524710561147024087061094945611445247184886124713813
7588545445084949098849167122714970453692617052452471056114702408706109494554614927834645527070484628289292921393081488051309240528713471497014289310071007075013483869
;

*check your log to read the message! ;

--Q.

[PeterClemmensen]

Clever 🙂

Looking forward!

[Quentin]

Thanks @PeterClemmensen .  Glad it worked!  I've been enjoying the hashing posts on your blog, e.g. https://sasnrd.com/sas-hash-object-content-log-puthash/ .

[jimbarbour]

@Quentin 

Now that's a novel means of communication.

I signed up.  Hopefully no one will assign me a conflict at work.

Jim

P.S.  I suppose a more proper response would be:

91710824452588714970614919
435208492745230988453471242345228816524569092445230988244527614938456149346170087061094913
41450524087071698854542345081616714870194508493845414508224554090927614905456909249208243845700945617013
29614916712471542345230988241419
336122