About
Articles Related
Syntax
merge(x = df1, y = df2, by = "Name")
merge(
x = df1,
y = df2,
by = intersect(names(x), names(y)),
by.x = by,
by.y = by,
all = FALSE, -- Shorthand for all.x and all.y
all.x = all,
all.y = all,
sort = TRUE,
suffixes = c(".x",".y"), -- To make unique the columns names
incomparables = NULL,
...
)
where:
- the “by” parameters specifies the join column. Default: join by common variable names
- The by.x and by.y parameters must be used if the matching variables have different names
- the “all” parameters specifies which non matching row is returned.
- sort: Should the result be sorted on the by columns?
The default method coerces the arguments to data frames and calls the “data.frame” method.
Join
Inner
merge(df1, df2)
Outer
Left outer
merge(x = df1, y = df2, by = "Name", all.x = TRUE)
Right outer
merge(x = df1, y = df2, by = "Name", all.y = TRUE)
Full OUter
merge(x = df1, y = df2, by = "Name", all.y = TRUE, all.x = TRUE)
# or
merge(x = df1, y = df2, by = "Name", all = TRUE)
Cross
merge(x = df1, y = df2, by = NULL)