r-在特定条件下对数据帧进行子集处理

Question

如何获取一个数据帧的行，该数据帧的元素中的值与另一数据帧的值相同？我写过这个，但没用。

 # example of two data frame
    df1 <- data.frame(V1 = c("a", "g", "h", "l", "n", "e"), V2 = c("b", "n", "i", "m", "i", "f"), stringsAsFactors = F)
    df2 <- data.frame(V1 = c("a", "c", "f","h"), V2 = c("b", "d", "e","z"), stringsAsFactors = F)
    # finding joint values in each element of two data frames
    res1<-intersect(df1$V1,df2$V1)
    res2<-intersect(df1$V2,df2$V2)
    res3<-intersect(df1$V1,df2$V2)
    res4<-intersect(df1$V1,df2$V2)
    # Getting rows that has joint value at least in one element of df1
    ress1<-df1[apply(df1, MARGIN = 1, function(x) all(x== res1)), ]
    ress2<-df1[apply(df1, MARGIN = 1, function(x) all(x== res2)), ]
    ress3<-df1[apply(df1, MARGIN = 1, function(x) all(x== res3)), ]
    ress4<-df1[apply(df1, MARGIN = 1, function(x) all(x== res4)), ]
    # Getting rows that has joint value at least in one element of df2
    resss1<-df2[apply(df2, MARGIN = 1, function(x) all(x== res1)), ]
    resss2<-df2[apply(df2, MARGIN = 1, function(x) all(x== res2)), ]
    resss3<-df2[apply(df2, MARGIN = 1, function(x) all(x== res3)), ]
    resss4<-df2[apply(df2, MARGIN = 1, function(x) all(x== res4)), ]
    # then combine above results
    final.res<-rbind(ress1,ress2,ress3,ress4,resss1,resss2,resss3,resss4)

我最喜欢的结果是：

a   b
h   z
h   i
f   e
e   f

Answer 1

这应该能在中工作

#Import data
df1 <- data.frame(V1 = c("a", "g", "h", "l", "n", "e"), V2 = c("b", "n", "i", "m", "i", "f"), stringsAsFactors = F)  
df2 <- data.frame(V1 = c("a", "c", "f","h"), V2 = c("b", "d", "e","z"), stringsAsFactors = F)
# Get the intersects
vals <- intersect(c(df1$V1, df1$V2), c(df2$V1, df2$V2))
#Get the subsets and rbind them
full <- rbind(
 subset(df1, df1$V1 %in% vals),
 subset(df1, df1$V2 %in% vals),
 subset(df2, df2$V1 %in% vals),
 subset(df2, df2$V2 %in% vals)
)
#Remove duplicates  
full <- full[!duplicated(full),]