修改SAS中宏变量的值(Modifying the value of macro variable in SAS)

 我使用％let选项在我的sas代码中创建了两个宏变量。 
 
data sasdata1.dataone;
set sasdata1.dataone ;
%let week=1;
%let sum=0;
do i=1 to 53;
%let sum= _W&week._NRX + &sum.;
week=&week+1;
end;
drop i;
week=&week;
sum=&sum.;
run;
 
 即使在循环执行后，周变量的值仍为1。 哪个是更改宏变量值的正确方法？ 

I created two macro variables in my sas code using the %let option.
 
data sasdata1.dataone;
set sasdata1.dataone ;
%let week=1;
%let sum=0;
do i=1 to 53;
%let sum= _W&week._NRX + &sum.;
week=&week+1;
end;
drop i;
week=&week;
sum=&sum.;
run;
 
the value of the week variable remains 1 even after the loop has executed. Which is the correct way to change the value of Macro variables?

原文：https://stackoverflow.com/questions/17651481