as.integer的帮助里
Non-integral numeric values are truncated towards zero (i.e., as.integer(x) equals trunc(x) there), and imaginary parts of complex numbers are discarded (with a warning).
其次
> 40*(1-0.8)-8
[1] -1.776357e-15
精度的问题
在这里面不要用as.integer,用round好了