我有一组数据,其中包含有关客户的信息以及他们花了多少钱,每个客户只出现一次:
customer<-c("Andy","Bobby","Oscar","Oliver","Jane","Cathy","Emma","Chris")
age<-c(25,34,20,35,23,35,34,22)
gender<-c("male","male","male","male","female","female","female","female")
moneyspent<-c(100,100,200,200,400,400,500,200)
data<-data.frame(customer=customer,age=age,gender=gender,moneyspent=moneyspent)
如果我想计算男性和女性客户平均花费的金额,我可以使用tapply:
tapply(moneyspent,gender,mean)
这使:
female male
375 150
但是,我现在想找出性别和年龄组的平均花费,我的目标是:
Male Age 20-30 Female Age 20-30 Male Age 30-40 Female Age 30-40
150 300 150 450
我怎样才能修改 tapply 代码以便它给出这些结果?
谢谢你