Creates or validates a subclass of a tibble. These function is mostly useful for package authors that implement subclasses of a tibble, like sf or tsibble.
new_tibble()
creates a new object as a subclass of tbl_df
, tbl
and data.frame
.
This function is optimized for performance, checks are reduced to a minimum.
See vctrs::new_data_frame()
for details.
validate_tibble()
checks a tibble for internal consistency.
Correct behavior can be guaranteed only if this function
runs without raising an error.
new_tibble(x, ..., nrow = NULL, class = NULL, subclass = NULL) validate_tibble(x)
x | A tibble-like object. |
---|---|
... | Name-value pairs of additional attributes. |
nrow | The number of rows, inferred from |
class | Subclasses to assign to the new object, default: none. |
subclass | Deprecated, retained for compatibility. Please use the |
For new_tibble()
, x
must be a list.
The nrow
argument may be omitted as of tibble 3.1.4.
If present, every element of the list x
should have vctrs::vec_size()
equal to this value.
(But this is not checked by the constructor).
This takes the place of the "row.names" attribute in a data frame.
x
must have names (or be empty),
but the names are not checked for correctness.
validate_tibble()
checks for "minimal" names
and that all columns are vectors, data frames or matrices.
It also makes sure that all columns have the same length,
and that vctrs::vec_size()
is consistent with the data.
tibble()
and as_tibble()
for ways to construct a tibble
with recycling of scalars and automatic name repair,
and vctrs::df_list()
and vctrs::new_data_frame()
for lower-level implementations.
# The nrow argument is always required: new_tibble(list(a = 1:3, b = 4:6), nrow = 3) #> # A tibble: 3 × 2 #> a b #> <int> <int> #> 1 1 4 #> 2 2 5 #> 3 3 6 # Existing row.names attributes are ignored: try(validate_tibble(new_tibble(trees, nrow = 3))) #> Error : Tibble columns must have compatible sizes. #> * Size 3: Requested with `nrow` argument. #> * Size 31: Columns `Girth`, `Height`, and `Volume`. #> ℹ Only values of size one are recycled. # The length of all columns must be compatible with the nrow argument: try(validate_tibble(new_tibble(list(a = 1:3, b = 4:6), nrow = 2))) #> Error : Tibble columns must have compatible sizes. #> * Size 2: Requested with `nrow` argument. #> * Size 3: Columns `a` and `b`. #> ℹ Only values of size one are recycled.