Hello
The below code will mark each zero across the variables V1 to V10 (Column) as missing value (.dot)
data credit;
set file;
array x(*) V1 -- V10;
do i=1 to dim(x);
if x(i)=0 then x(i)=.;
end;
run;
Let's say in regression analysis while creating dummy variables, X variable has 7 categories and I would like to create dummy variables for those 7 categories.
How can I write codes using array or macros to create dummy variables, Is it possible?
Need help.
You could also use an ARRAY to help with making dummy variables. So if X has 7 values (1 to 7) then this code will make variables DUMMY1 to DUMMY7 with 0/1 values.
data want ;
set have ;
array dummy (7);
do i=1 to dim(dummy);
dummy(i)=(x=i);
end;
run;
Note that if X is not simply the values 1 to 7 then it is a little harder. You should look at the GLMMOD procedure as a way to generate dummy variables.
You could also use an ARRAY to help with making dummy variables. So if X has 7 values (1 to 7) then this code will make variables DUMMY1 to DUMMY7 with 0/1 values.
data want ;
set have ;
array dummy (7);
do i=1 to dim(dummy);
dummy(i)=(x=i);
end;
run;
Note that if X is not simply the values 1 to 7 then it is a little harder. You should look at the GLMMOD procedure as a way to generate dummy variables.
Assuming X is numeric, you don't need to know the number of values ahead of time. Here is the idea:
proc sql noprint;
select distinct X into : list_of_x separated by ' ' from have;
quit;
data want;
set have;
%do i=1 %to &sqlobs;
dummy&i = (x=%scan(&list_of_x, &i));
%end;
run;
Of course, you will need to define a macro to hold the logic, because of the %DO loop.
Good luck.
Available on demand!
Missed SAS Innovate Las Vegas? Watch all the action for free! View the keynotes, general sessions and 22 breakouts on demand.
Learn how use the CAT functions in SAS to join values from multiple variables into a single value.
Find more tutorials on the SAS Users YouTube channel.