sas累積收益多個變量

Question

我一直在運行一個datastep來計算變量X1的累積積，給它一個起始值1.但是，我無法使用％do循環爲幾個變量運行它。我在下面提供兩個代碼。幫助讚賞。

DATA HAVE; 
INFILE DATALINES DSD; 
INPUT X1 X2 X3 YEAR; 
DATALINES; 
0.99,0.98, 0.97,2005 
0.975,0.96, 0.923,2006 
0.983,0.934, 0.93,2007 
0.978,0.93, 0.887,2008 
; 

data working; 
set have; 
retain R1 1; 
S1=R1*X1; 
output; 
R1=S1; 
drop S1; 
run; 


%macro macro5(j); 
data notworking; 
set have; 
%DO i=1 %to &j; 
retain R&i 1; 
S&i=R&i*X&i; 
output; 
R&i=S&i; 
drop S&i; 
%end; 
run; 
%mend; 
%macro5(3); 

Answer 1

使用數組而不是宏循環。

DATA HAVE; 
INFILE DATALINES DSD; 
INPUT X1 X2 X3 YEAR; 
DATALINES; 
0.99,0.98, 0.97,2005 
0.975,0.96, 0.923,2006 
0.983,0.934, 0.93,2007 
0.978,0.93, 0.887,2008 
; 

data want; 
set have; 
array x(3) x1-x3; 
array r(3) r1-r3; 

retain r1-r3 1; 

output; 

do i=1 to 3; 
r(i)=x(i)*r(i); 
end; 

drop i; 
run;