scofieldkang 发表于 2011-7-10 20:53
要用sas啊 ，现在基本不用这东西了，都用spss了

honghejing 发表于 2011-7-10 22:17
data b;
  set a;
retain c 0;
  if first.a then c=value1;
  else c+value1;
  value2=c+1/2*value1;
run;
run;

tj0412ymy 发表于 2011-7-10 23:54

honghejing 发表于 2011-7-10 22:17
data b;
  set a;
retain c 0;
  if first.a then c=value1;
  else c+value1;
  value2=c+1/2*value1;
run;
run;

非常感谢给予解答，略做修改后的正解为：
data b;
  set a;
by Category;
retain c 0;
  if first.Category then c=value1;
  else c+value1;
  value2=c-1/2*value1;
run;