数据data里面的date想加上星期几,用data美元符号dow<-as.factor(weekdays(data美元符号date))提示
Error in UseMethod("weekdays") :
no applicable method for 'weekdays' applied to an object of class "factor"
怎么回事呢?
用data美元符号month<-as.factor(months(data美元符号date))也提示
Error in UseMethod("months") :
no applicable method for 'months' applied to an object of class "factor"
date
2015/12/1
2015/12/10
2015/12/11
2015/12/12
2015/12/13
2015/12/14