playwith(xyplot(mpg~wt|factor(cyl)*factor(am),data=mtcars,
subscripts=TRUE,type=c("r","p")))
这是一句 R in action 书中的代码,但是我运行时,却报错了
Error in playwith(xyplot(mpg ~ wt | factor(cyl) * factor(am), data = mtcars, : attempt to apply non-function
显示的GUI窗口 也没有图形,这是为什么???