number=50
data <- matrix(nrow = number, ncol = 3 )
colnames(data) <- c("ID",  "Shop_year", "Region")
set.seed(1) 
data[,1] <- c(sample(1:25, size=number, replace = T) )#ID

data[,2] <- c(sample(c("year2013","year2014","year2015"), size=number, replace= T, prob = c(0.1, 0.3, 0.6) ) ) 
data[,3] <- c(sample(c("北區一","北區二","北區三"), size = number,
                     replace = T, prob = c(0.5,0.3,0.2) ))
data <- data.frame(data)

library(reshape2)
library(reshape)
result<- cast(data, ID~Shop_year,value=c("Region"))

##分類成三組
data_new <- filter(result, year2015 !=0 & year2014 == 0)
data_new$level <- "新增"
data_lost <- filter(result, year2015 == 0)
data_lost$level <- "流失"
data_now <- filter(result, year2015 != 0 & year2014 !=0)
data_now$level <- "回購"

##合併檔案
data_combine <- rbind.data.frame(data_now, data_new, data_lost)
## 新增分組資料到原始檔案
data_final <- merge(data, data_combine)