Date:         Thu, 15 Sep 2005 14:21:31 -0400
Reply-To:     Arthur Tabachneck <art297@NETSCAPE.NET>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Arthur Tabachneck <art297@NETSCAPE.NET>
Subject:      Re: help on translating Talbot Michael Katz's "discontinue a test
              code"
Comments: To: Dew Meng <meng4sas@GMAIL.COM>

Mimi,

Assuming there were some variable name changes and extra asterisks in your
code, and that the following more closely approximates what your code
looks like, the explanation is straight forward:

data tdm1;
  input teid age @7 (bds01-bds20)(1.);
  cards;
110 6 00011100011000010110
111 7 00100011000000000000
;
run;

data tdm2 ;
  set tdm1;
  array bds(*) bds: ;
  drop i triple ;
  triple = 0;
  do i = lbound(bds) to hbound(bds) ;
    if triple < 3 then triple =(triple + 1) * (bds{i} = 0) ;
     else bds{i} = 0 ;
  end ;
run;

Triple serves as a counter of the number of consecutive 0s.  It starts out
as zero and, after it finds three consecutive 0s it sets all remaining bds
values to 0.

The counter works by incrementing by 1 (i.e., triple=triple+1) if the
current value is not zero, since it multiplies triple times the logical
result (i.e., 0 if false, 1 if true) of whether the current value is equal
to zero.  So, if it finds a second consecutive zero, it makes triple equal
to triple + 1 (or, in this case, 1+1=2) times 1 (since the current value
is zero).  If the current value was not equal to zero, then triple would
be reset to zero.

Art
----------
Thu, 15 Sep 2005 12:30:43 -0500, mimi <meng4sas@GMAIL.COM> wrote:

> would you please help me on explaning the code that Talbot suggested on
how
>to discontinue a test.
> Here is the situation.
>I want to score all the items to 0s after 3 consecutive 0 occurs.
>here is the fake data: