topic Re: Need help to understand macro! If possible please kindly explain me. in SAS Programming

Need help to understand macro! If possible please kindly explain me.

Cathy — Thu, 14 Apr 2016 07:31:37 GMT

I need to create a macro. I have dataset having variables from v1 to v7 (independent variables) and y for response. the number of predictors using "varnum" for execution.

Create the macro for each predictors, with simple linear regression and gplot. Please help how I can start with coding. Thanks.

Re: Need help to understand macro! If possible please kindly explain me.

Kurt_Bremser — Thu, 14 Apr 2016 07:59:49 GMT

Very simple, but may lead you in the right direction:

%macro regressions (varnum);
%do i = 1 %to &varnum;
proc reg;
  model y=v&i;
run;
%end;
%mend;

Re: Need help to understand macro! If possible please kindly explain me.

RW9 — Thu, 14 Apr 2016 08:17:52 GMT

Hi,

Well, your problem seems to lie in the way you have set your data up - i.e. wide rather than long. I am not familiar with proc reg, so am guessing a bit on syntaxt here, but all procedures are built to allow by group processing - which is both faster, and more efficient, plus easier to maintain. To use this however your data needs to be long data rather than wide. Don't confuse what data you may use in an output review file (which is likely to need transposing) with data you use for your programming, the two can be totally different. An example below shows how to normalise your data, and then use a by grou - see how much simpler the code is, easier to maintain, no macro at all just plain base SAS - note that you have not provided any test data (in the form of a datastep) so this is just an example:

proc transpose data=have out=t_have;
  by <id variables>;  /* Replace with your id variables */
  var v:;
run;
proc reg data=t_have;
  by _name_;
  model y=col1;
run;

Re: Need help to understand macro! If possible please kindly explain me.

stat_sas — Thu, 14 Apr 2016 12:10:05 GMT

If you are looking for predictors contributing more in the model then you can try selection criteria based on rsquare to flag predictors for the final model:

proc reg data=have;
model y=v:/selection=rsquare;
plot r.*(p. v: );
plot student.*obs. / vref=3 2 -2 -3;
run;
quit;

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Thu, 14 Apr 2016 22:38:43 GMT

%macro regressions (varnum);
%do i = 1 %to &varnum;
proc reg data=new;
model y=v&i;
run;
proc gplot data=new;
plot y*i/vaxis= 0 to 1 by 0.1;
run;
%end;
%mend;
%regressions(5)

I got it for regression. But how can I use proc gplot ? It does not work with macro. It shows that at least one plot or bubble statement must be given.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Thu, 14 Apr 2016 19:22:29 GMT

thank you, but I need to use macro for this.

Re: Need help to understand macro! If possible please kindly explain me.

FreelanceReinh — Thu, 14 Apr 2016 21:52:48 GMT

Hi @Cathy,

The plot request should read y*v&i rather than y*i.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Thu, 14 Apr 2016 23:29:29 GMT

Thank you.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Fri, 15 Apr 2016 01:36:22 GMT

I have a question regarding using this code;

for example if I want to create start at 3 and stop at 5.

%macro questions(start=3,stop=5);
%do i = &start %to &stop;
proc reg data=new;
model y=v&i;
run;
%do j=&i+1 %to &stop+1;
proc gplot data=new;
plot v&i*v&j;
run;
%end;
%end;
%mend;
%questions(3)

Please help me this too. Thanks.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Fri, 15 Apr 2016 01:37:19 GMT

I got this...%questions((start=3,stop=5)

it print out...finally

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Fri, 15 Apr 2016 01:38:00 GMT

Thanks a lot, I got it finally and giving me a good direction.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Fri, 15 Apr 2016 01:38:34 GMT

Thanks a lot again. This helps me a lot too

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Fri, 15 Apr 2016 01:38:48 GMT

Thank you so much too.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Fri, 15 Apr 2016 01:39:02 GMT

Thank you so much.

Re: Need help to understand macro! If possible please kindly explain me.

RW9 — Fri, 15 Apr 2016 08:18:51 GMT

Why? There is never a "need" to use any tool, use the one thats fits the job best? Macro language is designed as a code generation toolkit, nothing more, Base SAS is the programming language.

Re: Need help to understand macro! If possible please kindly explain me.

Cathy — Sat, 16 Apr 2016 04:16:54 GMT

I am studying little SAS book and preparing to get certificate too. That's why I need to know macro too. Thank you.