new_data_frame()
constructs a new data frame from an existing list. It is
meant to be performant, and does not check the inputs for correctness in any
way. It is only safe to use after a call to df_list()
, which collects and
validates the columns used to construct the data frame.
Usage
new_data_frame(x = list(), n = NULL, ..., class = NULL)
Arguments
- x
A named list of equal-length vectors. The lengths are not checked; it is responsibility of the caller to make sure they are equal.
- n
Number of rows. If
NULL
, will be computed from the length of the first element ofx
.- ..., class
Additional arguments for creating subclasses. The
"names"
and"row.names"
attributes override input inx
andn
, respectively:"names"
is used if provided, overriding existing names inx
"row.names"
is used if provided, ifn
is provided it must be consistent.
See also
df_list()
for a way to safely construct a data frame's underlying
data structure from individual columns. This can be used to create a
named list for further use by new_data_frame()
.
Examples
new_data_frame(list(x = 1:10, y = 10:1))
#> x y
#> 1 1 10
#> 2 2 9
#> 3 3 8
#> 4 4 7
#> 5 5 6
#> 6 6 5
#> 7 7 4
#> 8 8 3
#> 9 9 2
#> 10 10 1