按关键列合并两个data.frames [英] Merging two data.frames by key column

问题描述

我有两个数据框。在第一个中，我有一个KEY / ID列和两个变量：

I have two dataframes. In the first one, I have a KEY/ID column and two variables:

KEY V1 V2
1   10  2
2   20  4
3   30  6   
4   40  8
5   50 10

在第二个数据帧中，我有一个KEY / ID列和第三个变量

In the second dataframe, I have a KEY/ID column and a third variable

KEY V3 
1    5  
2   10  
3   20  

我想通过根据KEY列进行匹配来提取也在第二个数据帧中的第一个数据帧的行。我还想将V3列添加到最终数据集中。

I would like to extract the rows of the first dataframe that are also in the second dataframe by matching them according to the KEY column. I would also like to add the V3 column to final dataset.

KEY V1 V2 V3 
1   10  2  5
2   20  4 10 
3   30  6 20   

这是我尝试使用子集和合并函数

This are my attempts by using the subset and the merge function

subset(data1, data1$KEY == data2$KEY) 
merge(data1, data2, by.x = "KEY", by.y = "KEY")

无他们会完成任务。

任何提示都会得到体现。谢谢！

Any hint would be appreaciated. Thank you!

推荐答案

merge（data1，data2，by = KEY）应该这样做！

这篇关于按关键列合并两个data.frames的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！