Date:         Wed, 21 Jul 2004 03:07:22 GMT
Reply-To:     julierog@ix.netcom.com
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Roger Lustig <trovato@VERIZON.NET>
Subject:      Re: A simpler way?
Content-Type: text/plain; charset=us-ascii; format=flowed

Dear Pat:

Don't know about "sophisticated", but how about "terse"?

If all you want is the GPA at the end, how about:

array grade (6) p1grnum p2grnum p3grnum p4grnum p5grnum p6grnum;

do I=1 to 6;
     if grade(I) >=4 then do;
        total = sum(total,grade(I);
        counted=sum(counted,1);
        end;
     end;

if counted > 0 then preqgpa = total / counted;

drop counted total I;

This has the advantage of being easy to modify in case, say, more than 6
grades are involved.

Of course, further efficiency might come from naming the grade variables
so that the number is at the end:

array grade (6) pgrnum1-pgrnum6;

If the variables are indeed named that way, you can even enumerate them
implicitly:

array pgrnum (6);

If you need the recoded grades, you can do the following:
array pg (6);
do I=1 to 6;
     if grade(I) >=4 then do;
        pg(I) = grade(I)-4;
        total = sum(total,grade(I);
        counted=sum(counted,1);
        end;
     end;
<etc>

Note that you don't have to set the other recoded grades to
missing--they're already that way.

OK?

Roger

Pat Moore wrote:
> I have variables p1grnum--p6grnum that each vary from 0-8.  I wrote this
> code:
>
> /*this makes grnums below 4 negative numbers*/
>   p1g=p1grnum-4;
>   p2g=p2grnum-4;
>   p3g=p3grnum-4;
>   p4g=p4grnum-4;
>   p5g=p5grnum-4;
>   p6g=p6grnum-4;
> /*this sets negative values of p1g-p6g to missing so non-letter grades are
> not computed into the gpa*/
>   if p1g<0 then p1g=.;
>   if p2g<0 then p2g=.;
>   if p3g<0 then p3g=.;
>   if p4g<0 then p4g=.;
>   if p5g<0 then p5g=.;
>   if p6g<0 then p6g=.;
> /*this computes the grade point average with the modified values*/
>   preqgpa=mean(p1g,p2g,p3g,p4g,p5g,p6g);
>
> Is there some more sophisticated way to do this?