topic Perl Regular Expression simple case in SAS Programming

Perl Regular Expression simple case

saskapa — Fri, 08 Jan 2016 18:32:02 GMT

I would like to convert variable 'res' into numeric. But I would like to do it for the records that only have digit value ( in our case it is 12.3 ). So I used a perl regular expression. But I have tried write an expression so that the returned value of prxmatch is equal to 0 for 12.3 and non zero for other cases. It doesn work...Any clue ?

Cheers

SasKap

data test;
input res $20.;
 p=prxparse("/\<\>\+\D/");
 pos=prxmatch(p,res);

put var= p= pos=;
cards;
12.3
<5
>9
+5
unknown
;

run;

Re: Perl Regular Expression simple case

PGStats — Fri, 08 Jan 2016 19:54:53 GMT

Why is +5 not a number? I would do:

data test;
if not p then p + prxparse("/^[+-]?\d+\.?\d*/");
input res $20.;
pos=prxmatch(p,res);
put res= pos=;
cards;
12.3
<5
>9
+5
unknown
-123
;

Re: Perl Regular Expression simple case

ballardw — Fri, 08 Jan 2016 23:00:39 GMT

What would you like for your final output for that example? I'm not sure how you are going to use the 0 result.

Re: Perl Regular Expression simple case

Ksharp — Mon, 11 Jan 2016 05:04:58 GMT

Why not use ?? operator ?

data test;
input res $20.;
pos=input(res,?? best32.);
* input res ?? best32. ;
put res= pos=;
cards;
12.3
<5
>9
+5
unknown
-123
;
run;

Re: Perl Regular Expression simple case

saskapa — Mon, 11 Jan 2016 16:40:32 GMT

Hi PG,

Thanks. Could you please explain me what does \ ^[+-]? , \.? and \d* perform ?

Re: Perl Regular Expression simple case

saskapa — Mon, 11 Jan 2016 16:44:21 GMT

I would like to convert res into numeric. Unfortunately there are values that cant be converted to numeric, so if I run a perl function to identify the one that can be converted into numeric ( pos =0) than I'll run an input statement on it this value. saskap

Re: Perl Regular Expression simple case

saskapa — Mon, 11 Jan 2016 16:47:16 GMT

Thanks Ksharp. Could you please explain me '??' ? Is it just everything that is numeric only ?

Re: Perl Regular Expression simple case

ballardw — Mon, 11 Jan 2016 18:07:18 GMT

The ?? suppresses error messages when reading non-numeric values and does not set the automatic _ERROR_ variable to 1.

Re: Perl Regular Expression simple case

Ksharp — Tue, 12 Jan 2016 01:15:29 GMT

Someone has already answer your question. But I think the best way to understand it is to check SAS documnetation.

y=input(x, ?? best.);

<==>

y=input(x, ? best.);

_error_=1;

Re: Perl Regular Expression simple case

saskapa — Tue, 12 Jan 2016 10:17:51 GMT

Thanks. I have checked first the help documentation before raising the question but I could not find any answer. The only answer when typing '?' in the index search from help doc , was about greplay procedure....Nothing as well with google..

Cheers

Saskap

Re: Perl Regular Expression simple case

ballardw — Tue, 12 Jan 2016 18:25:10 GMT

You would find the answer under INPUT function in the documentation.