ttt = read.csv("c:\\users\\Administrator\\Desktop\\ttt.csv");
#attach(ttt);
library("plyr");
ttt1=mutate(ttt,date=as.Date(date,'%Y/%m/%d'))
summary(ttt);
subttt = subset(ttt1,date<=as.Date("2012-05-01"));
model = casecross(total ~ etem+ekpa+erh+ewind+ltem+htem+dow+holiday,data=subttt)
summary(model);
我用R软件读excel（ttt）里的数据,为什么不识别我的变量dow,显示
错误于eval(expr, envir, enclos) : 找不到对象'dow'