I have a dataframe "dfA" and dataframe "dfB"
str(dfA)
'data.frame':   594 obs. of  2 variables:
 $ DrainID: num  1673 1673 1674 1675 1675 ...
 $ L      : num  NA NA NA NA NA NA NA NA NA NA …
str(dfB)
'data.frame':   83 obs. of  2 variables:
 $ DrainID: num  1673 1674 1675 1676 1677 ...
 $ L      : num  35924 14027 17235 18156 24060 …
I want to replace dfA$L with dfB$L considering the DrainID which is common to both the dataframe.
I want my dataframe "dfA" to look like:
head(dfA)
  DrainID  L
1    1673 35924
2    1673 35924
3    1674 14027
4    1675 17235
5    1675 17235
6    1676 18156
Any help would be appreciated?
 
    