初学sas,老师讲的很简要。。例子讲的很快。。作业中有两道题不是很懂,写了部分code,写不下去了。。。需求帮助。。谢谢。。。
Write code to create a SAS data set that looks like the following 20 × 20 matrix:
X1 X2 X3 X4 ... X19 X20
1 . . . . .....................
2 1 . . . .....................
3 2 1 . . .................
...
19 18 17 16 ........1
20 19 18 17 ... 2 1
DATA a51;
Array abc [20] x1-x20;
Do i=1to 20;
DO j=1 to 20;
abc=i-j+1;
OUTPUT;
END;
END;
KEEP x1-x20;
RUN;
PROC print data=a51; RUN;
结果很不对。。。谢谢了
第二题:
Create a SAS data set that contains two variables: X and FactX. Assign X the values
{1, 0, 4,−2, 5} and define FactX as the factorial of X. The data should look like::
X FactX
1 1
0 1
4 24
-2 .
5 120
老师要求不能用 proc 或者 factorial function来做。。。用log后,然后exp
我的code
DATA fact2;
x=0;
a=0;
IF x>0 THEN do i= 2 to x;
a=a+log(i);
END;
factx= exp(a);
ELSE IF x<0 THEN factx=0;
ELSE factx=1;
RUN;
PROC PRINT data=fact2; RUN;
麻烦了。。。。