match_arrow {arrow} | R Documentation |
base::match()
and base::%in%
are not generics, so we can't just define Arrow methods for
them. These functions expose the analogous functions in the Arrow C++ library.
match_arrow(x, table, ...) is_in(x, table, ...)
x |
|
table |
|
... |
additional arguments, ignored |
match_arrow()
returns an int32
-type Arrow object of the same length
and type as x
with the (0-based) indexes into table
. is_in()
returns a
boolean
-type Arrow object of the same length and type as x
with values indicating
per element of x
it it is present in table
.
# note that the returned value is 0-indexed cars_tbl <- arrow_table(name = rownames(mtcars), mtcars) match_arrow(Scalar$create("Mazda RX4 Wag"), cars_tbl$name) is_in(Array$create("Mazda RX4 Wag"), cars_tbl$name) # Although there are multiple matches, you are returned the index of the first # match, as with the base R equivalent match(4, mtcars$cyl) # 1-indexed match_arrow(Scalar$create(4), cars_tbl$cyl) # 0-indexed # If `x` contains multiple values, you are returned the indices of the first # match for each value. match(c(4, 6, 8), mtcars$cyl) match_arrow(Array$create(c(4, 6, 8)), cars_tbl$cyl) # Return type matches type of `x` is_in(c(4, 6, 8), mtcars$cyl) # returns vector is_in(Scalar$create(4), mtcars$cyl) # returns Scalar is_in(Array$create(c(4, 6, 8)), cars_tbl$cyl) # returns Array is_in(ChunkedArray$create(c(4, 6), 8), cars_tbl$cyl) # returns ChunkedArray