Date:         Thu, 23 Sep 2010 08:55:40 -0500
Reply-To:     Joe Matise <snoopy369@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Joe Matise <snoopy369@GMAIL.COM>
Subject:      Re: Conditional find and replace in a text string
Comments: To: Paul Miller <pjmiller_57@yahoo.com>
In-Reply-To:  <410743.29568.qm@web57002.mail.re3.yahoo.com>
Content-Type: text/plain; charset=ISO-8859-1

_N_ here is being used as a convenient iterator variable that is
automatically dropped - it is not functioning as a row counter in this
particular instance (that is overridden by the do loop assignment).  You
could use __T or something else if you prefer.

-Joe

On Thu, Sep 23, 2010 at 8:46 AM, Paul Miller <pjmiller_57@yahoo.com> wrote:

> Hi Søren and Nat,
>
> Thanks for your replies to my post. Søren, your solution works
> particularly well and I was hoping you could help me understand a little
> better how it works.
>
> In your code you have the expression: "do _N_=3,5,9,11,13."
>
> I understand that _N_ is an automatic variable that counts the current
> interation within the data step. I've seen this used before to count the
> number of rows but I've never seen it used the way you have here.
>
> Can you give me a better sense of exactly how this works?
>
> Thanks,
>
> Paul
>
> --- On Thu, 9/23/10, Søren Lassen <s.lassen@POST.TELE.DK> wrote:
>
>
> From: Søren Lassen <s.lassen@POST.TELE.DK>
> Subject: Re: Conditional find and replace in a text string
> To: SAS-L@LISTSERV.UGA.EDU, "Paul Miller" <pjmiller_57@YAHOO.COM>
> Received: Thursday, September 23, 2010, 12:21 AM
>
>
> Paul,
> This is a good place to use assignments to substrings:
> data have;
> input text $50.;
> cards;
> 1 1 8 25 0
> 0
> 2 1
> 1 1 1 2 3 2 3 5
> 2 3 3 3 1 1 2 4
> 2 0
> ;
> run;
>
> proc format;
>   value $swap
>   '1'='3'
>   '3'='1'
>   ;
> run;
>
> data want;
>   set have;
>   if length(text)=15 then do _N_=3,5,9,11,13;
>     substr(text,_N_,1)=put(substr(text,_N_,1),$swap.);
>     end;
> run;
>
> I calculated the positions from the word numbers, as the words
> appear to be in fixed positions. If that is not the case, you can do:
>
> data want;
>   set have;
>   if length(text)=15 then do _N_=2,3,5,6,7;
>     call scan(text,_N_,_P,_L,' ');
>     substr(text,_P,_L)=put(substr(text,_P,_L),$swap.);
>     end;
>   drop _:;
> run;
>
>
> Regards,
> Søren
>
> On Wed, 22 Sep 2010 16:04:58 -0700, Paul Miller <pjmiller_57@YAHOO.COM>
> wrote:
>
> >Hello All,
> >?
> >Below is snippet from a design file for a conjoint analysis.
> >?
> >data test;
> >input text $50.;
> >cards;
> >1 1 8 25 0
> >0
> >2 1
> >1 1 1 2 3 2 3 5
> >2 3 3 3 1 1 2 4
> >2 0
> >;
> >run;
> >?
> >I'd like to do a find and replace that changes some of the values in lines
> with length = 15 (lines 4 and 5 in this example) according to the following
> set of criteria:
> >?
> >position???? action
> >1????????????? do nothing
> >2????????????? 1=3,2=2,3=1
> >3????????????? 1=3,2=2,3=1
> >4????????????? do nothing
> >5????????????? 1=3,2=2,3=1
> >6????????????? 1=3,2=2,3=1
> >7????????????? 1=3,2=2,3=1
> >8????????????? do nothing
> >?
> >where position is the location of the number within the text string.
> >?
> >Does anyone now a good way of doing this?
> >?
> >Thanks,
> >?
> >Paul
>
>
>
>