Date:         Thu, 15 Sep 2005 14:12:13 -0400
Reply-To:     Talbot Michael Katz <topkatz@MSN.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Talbot Michael Katz <topkatz@MSN.COM>
Subject:      Re: help on translating Talbot Michael Katz's "discontinue a test
              code"
Comments: To: Dew Meng <meng4sas@GMAIL.COM>

Hi, Mimi.

You've already seen the response I sent you privately, but I'll post it
here, too.


data    tdm2    ;
       set     tdm1    ;
       array   bds{*}  bds:    ;       *       group into array for
looping    ;
       drop    i       triple  ;       *       just for use in data
step       ;
       triple  =       0       ;       *       initialize flag to tell
when triple has been found      ;
       do      i       =       lbound(bds)     to      hbound
(bds)     ;       *       loop through entire array for each
record  ;
               if      triple  <       3       then    triple  =
(triple +       1)      *       (bds{i} =       0)      ;       *
this is where
all the work is being done.  if you have not hit a triple yet, every time
you see a zero, increment the triple counter.  if you see a one before the
triple counter gets to three, the triple counter gets reset to zero     ;
               else    bds{i}  =       0       ;       *       triple has
been hit, so set all remaining to 0  ;
       end     ;
run     ;



As I remarked to you, both Cassell and Chakravarthy offered better
solutions, which turn out to be more easily adaptible to other discontinue
criteria, such as three zeroes out of four:

data    tdm3    ;
       set     tdm1    ;
       array   bds{*}  bds:    ;       *       group into array for
looping    ;
       drop    i       j       hbm2    hbp1    lbp1    ;       *
just for use in data step       ;
       hbm2    =       hbound(bds)     -       2       ;       *
highest index to loop through   ;
       hbp1    =       hbound(bds)     +       1       ;       *       one
past the last index ;
       lbp1    =       lbound(bds)     +       1       ;       *
lowest index to loop through    ;
       do      i       =       lbp1    to      hbm2    while   (sum(bds
{i},bds{i+1},bds{i+2},bds{i-1}) >       1)      ;       *       tight
loop until reach end or violate rule    ;
       end     ;
       do      j       =       (((i    le      hbm2)   *       i)
+       ((i     >       hbm2)   *       hbp1))  to      hbound
(bds)     ;       *       if rule
violated, loop until end of array, setting to zero.  otherwise, set lower
bound past upper bound to avoid looping ;
               bds{j}  =       0       ;
       end     ;
run     ;


Good luck!

--  TMK  --
"The Macro Klutz"


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

>Hi, Everyone,
>especially Talbot :-)
> 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:
>*
>
>data tdm1;
>
>input teid age @7 (bd01-bd20)(1.);
>
>cards;
>
>110 6 00011100011000010110
>
>111 7 00100011000000000000
>
>;
>
>*here is what Talbot suggested.
>*
>
>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* ;
>
> but I don't really understand the logic here.
>
>can anyone explan line by line for me?
>
>Thanks.
>
> Mimi