scan in a proc data

[alisondu77]

Hello everyone,

From a macro variable declared by a user (year), i want to have the first day of all the month of the period.

For example if someone put : %let year = 2014 2015;  I want to have "01jan2014", "01feb2014", "01mar2014" ... "01nov2015" "01dec2015". I want to have this date save in different macro variable (date_1, date_2, date_3 ..., date_23, date_24).

So I have made a code, which works by half. I succeed in  having the "01mmm" but not the YYYY.

%global year;
%let year = 2014 2015 ;			/* the user choose the year*/

%global nb_year;
%let nb_year=%sysfunc(countw(&year.));
%put &nb_year. ; /*count the number of years*/

/* dates are saving in date_k (date_1 for "01jan2014", date_2 for '01feb2014"d ...) */
data _null_;
k=0;
ATTRIB month LENGTH=$5 ;
 do i=1 to (&nb_year.);
 year2 = scan(&year.,i,' ') ;	/*this step doesn't work*/
 	do j=1 to 12 ;				
		if j=1 then month= "01jan";
		if j=2 then month="01feb";
		if j=3 then month="01mar";
		if j=4 then month="01apr";
		if j=5 then month="01may";
		if j=6 then month="01jun";
		if j=7 then month="01jul";
		if j=8 then month="01aug";
		if j=9 then month="01sep";
		if j=10 then month="01oct";
		if j=11 then month="01nov";
		if j=12 then month="01dec" ;
		k=k+1;
		ym=(month)||(year2);
		call symput(cats('date_',k),ym);
	end;  
 end ; 
run ;
%put &date_20.;

So everything works except the lign where i declare "year2".

Can somenone help me to solve my problem ? Sorry for my poor english ...

Best regards,

Alison

[RW9 · Accepted solution]

Sorry, I really don't believe macro language is the best fit for data processing.  Its a fundamental misunderstanding of what macro code is for.  Macro is a text generation tool - it does nothing on its own, it has no data structures, it does not recognise dates or do calculation.  I would do:

%let year = 2014 2015;

data elements;
  do i=1 to countw("&year."," ");
    year=input(scan("&year.",i," "),best.);
    do j=1 to 12;
      date=mdy(j,1,year);
      output;
    end;
  end;
  format date date9.;
run;

You will see how simple the code is, just a couple of loops - this is the power of Base SAS using proper datatypes.  You can then use this dataset anyway you like - for instance in() lists, merging and such like.  And if you really need macro variables use call symput(), however I would strongly advise against it.

[alisondu77]

Thank you so much for your answer and your advice. It works very well 😉

Best regards.

Alison

[Reeza]

It should be:

Year2 = scan("&year", i);

But you'd be better off using SAS dates. 

Do j=1 to 12;
Date= mdy(j, 1, year2);
k+1;
Call symputx('date_'||k, put(date, date9.));
End;

[alisondu77]

Yes, thank you it works too. I didn't know that we have to put " " around the macro-variable in a scan. Thank you ! Have a nice day 😉

Alison