proc model 可以解决这个问题

非常感谢

不过在Nlin中发现这个，是不是可以通过定义_LOSS_来达到目的呢？不知道哪里能找到关于这个的详细介绍

还有，奇怪的是在Nlin参数初值搜索时，对于某个给定的参数值，计算的Sum of Loss和我在Excel表格里面的结果不一样。

_LOSS_
is used to determine the criterion function for convergence and step shortening. PROC NLIN looks for the variable _LOSS_ in the program statements and, if it is defined, uses the (weighted) sum of this value instead of the residual sum of squares to determine the criterion function for convergence and step shortening. This feature is useful in certain types of maximum-likelihood estimation where the residual sum of squares is not the basic criterion.

    呵呵 我发现问题了 自己写错了 :)

    谢谢帮助