请教logisitc回归问题

shiyiming

昨天装了个SAS8.1
但是似乎只能运行线性回归
运行logistic回归时却出错

1    DATA EX2;
2    INPUT X1 X2 D COUNT @ @;
3    CARDS;

NOTE: The data set WORK.EX2 has 4 observations and 4 variables.
NOTE: DATA statement used:
      real time           0.61 seconds
      cpu time            0.05 seconds


8    ;
9    PROC LOGISTIC DESCENDING;
10   FREQ COUNT;
11   MODEL D=X1 X2/SCALE=NONE AGGREGATE;
12   RUN;

ERROR: All observations have the same response.  No statistics are computed.
NOTE: The SAS System stopped processing this step because of errors.
NOTE: There were 4 observations read from the data set WORK.EX2.
NOTE: PROCEDURE LOGISTIC used:
      real time           0.60 seconds
      cpu time            0.06 seconds


现在才刚开始自学
所以很多都不明白
请教哪位高人能指点一二
感激不尽！

shiyiming

你查看一下你的目标变量，是不是常数！！！
最好把数据也贴出来，别人才能更好的给你查找原因！