来源：http://bbs.pinggu.org/thread-1219536-1-1.html
################ 生成数据
bh=1:100
jxh=rep(1:17,c(4,5,6,7,8,4,5,6,7,8,4,5,5,5,6,7,8))
relation=c(0,5,6,10,0,5,6,10,11,0,5,6,10,11,12,0,5,6,10,11,12,13,0,5,6,10,11,12,13,14,
0,5,6,10,0,5,6,10,11,0,5,6,10,11,12,0,5,6,10,11,12,13,0,5,6,10,11,12,13,14,
0,5,6,10,0,5,6,10,11,0,5,6,10,11,0,5,6,10,11,0,5,6,10,11,12,0,5,6,10,11,12,13,
0,5,6,10,11,12,13,14)
nn=length(jxh) ##nn=100
jx=unique(jxh) ##jx=17
datajx=data.frame(jxh,relation,bh)
data1=data.frame(datajx[relation==5,])
data2=data.frame(datajx[relation==6,])
data1=data1[,-2]
data2=data2[,-2]
colnames(data1)[2]="did"
colnames(data2)[2]="mid"
data3=merge(datajx,data1,by.x="jxh",by.y="jxh")
data4=merge(data3,data2,by.x="jxh",by.y="jxh") ###data4=merge(data3,data2,by="jxh")
################ 不用for循环，实现赋值
data5 <- data4
data5[(relation == 5) | (relation == 6), 4:5] <- 0