R - Add data from another dataframe based on matching values

Question

I have 2 dataframes like this:

 x1= c("Station 1", "Station 3", "Station 4")
 x2= c(1, 4, 2)
 df1 = data.frame(Station=x1, Number=x2) 

 x1= c("Station 1", "Station 2", "Station 3", "Station 4", "Station 5", "Station 6")
 x2= seq(-2,10 , length=6)
 x3= seq(30, 45, length=6)
 x4= seq(1, 16, length=6)
 x5= seq(4, 16, length=6)
 df2 = data.frame(Station=x1, Lon=x2, Lat=x3, Area=x4, Mis=x5)

> df1
  Station        Number
1 Station 1      1
2 Station 3      4
3 Station 4      2

> df2
  Station    Lon Lat Area  Mis
1 Station 1 -2.0  30    1  4.0
2 Station 2  0.4  33    4  6.4
3 Station 3  2.8  36    7  8.8
4 Station 4  5.2  39   10 11.2
5 Station 5  7.6  42   13 13.6
6 Station 6 10.0  45   16 16.0

For the 3 Stations I have in df1 I want to extract the data from the 2nd dataframe (for Lon, Lat and Area). So I want to add the Lon, Lat and Area to df1 for the Stations 1, 3 and 4.

I want it look like this then:

> dfnew
  Station        Number   Lon    Lat  Area
1 Station 1      1       -2.0     30    1
2 Station 3      4        2.8     36    7
3 Station 4      2        5.2     39   10

Can someone help please?

This is a `merge()` or `dplyr::left_join()` operation. See duplicate. — MrFlick, Jan 18 '18 at 19:15

score 1 · Accepted Answer · answered Jan 18 '18 at 19:16

Using dplyr:

library(dplyr)      
df_new <- inner_join(df1, df2, by = "Station")
df_new$Mis <- NULL

df_new:

     Station Number  Lon Lat Area
1    Station 1      1 -2.0  30    1
2    Station 3      4  2.8  36    7
3    Station 4      2  5.2  39   10

R - Add data from another dataframe based on matching values

1 Answers1