ChunkedArray-class: ChunkedArray class
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ChunkedArray R Documentation
ChunkedArray class
Description
A ChunkedArray is a data structure managing a list of
primitive Arrow Arrays logically as one large array. Chunked arrays
may be grouped together in a Table.
Factory
The ChunkedArray$create() factory method instantiates the object from
various Arrays or R vectors. chunked_array() is an alias for it.
Methods
-
$length(): Size in the number of elements this array contains
-
$chunk(i): Extract an Array chunk by integer position
'$nbytes() : Total number of bytes consumed by the elements of the array
-
$as_vector(): convert to an R vector
-
$Slice(offset, length = NULL): Construct a zero-copy slice of the array
with the indicated offset and length. If length is NULL, the slice goes
until the end of the array.
-
$Take(i): return a ChunkedArray with values at positions given by
integers i. If i is an Arrow Array or ChunkedArray, it will be
coerced to an R vector before taking.
-
$Filter(i, keep_na = TRUE): return a ChunkedArray with values at positions where
logical vector or Arrow boolean-type (Chunked)Array i is TRUE.
-
$SortIndices(descending = FALSE): return an Array of integer positions that can be
used to rearrange the ChunkedArray in ascending or descending order
-
$cast(target_type, safe = TRUE, options = cast_options(safe)): Alter the
data in the array to change its type.
-
$null_count: The number of null entries in the array
-
$chunks: return a list of Arrays
-
$num_chunks: integer number of chunks in the ChunkedArray
-
$type: logical type of data
-
$View(type): Construct a zero-copy view of this ChunkedArray with the
given type.
-
$Validate(): Perform any validation checks to determine obvious inconsistencies
within the array's internal data. This can be an expensive check, potentially O(length)
See Also
Array
Examples
# Pass items into chunked_array as separate objects to create chunks
class_scores <- chunked_array(c(87, 88, 89), c(94, 93, 92), c(71, 72, 73))
class_scores$num_chunks
# When taking a Slice from a chunked_array, chunks are preserved
class_scores$Slice(2, length = 5)
# You can combine Take and SortIndices to return a ChunkedArray with 1 chunk
# containing all values, ordered.
class_scores$Take(class_scores$SortIndices(descending = TRUE))
# If you pass a list into chunked_array, you get a list of length 1
list_scores <- chunked_array(list(c(9.9, 9.6, 9.5), c(8.2, 8.3, 8.4), c(10.0, 9.9, 9.8)))
list_scores$num_chunks
# When constructing a ChunkedArray, the first chunk is used to infer type.
doubles <- chunked_array(c(1, 2, 3), c(5L, 6L, 7L))
doubles$type
# Concatenating chunked arrays returns a new chunked array containing all chunks
a <- chunked_array(c(1, 2), 3)
b <- chunked_array(c(4, 5), 6)
c(a, b)
arrow documentation built on Nov. 25, 2023, 1:09 a.m.
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| ChunkedArray | R Documentation |
ChunkedArray class
Description
A ChunkedArray is a data structure managing a list of
primitive Arrow Arrays logically as one large array. Chunked arrays
may be grouped together in a Table.
Factory
The ChunkedArray$create() factory method instantiates the object from
various Arrays or R vectors. chunked_array() is an alias for it.
Methods
-
$length(): Size in the number of elements this array contains -
$chunk(i): Extract anArraychunk by integer position '$nbytes() : Total number of bytes consumed by the elements of the array
-
$as_vector(): convert to an R vector -
$Slice(offset, length = NULL): Construct a zero-copy slice of the array with the indicated offset and length. If length isNULL, the slice goes until the end of the array. -
$Take(i): return aChunkedArraywith values at positions given by integersi. Ifiis an ArrowArrayorChunkedArray, it will be coerced to an R vector before taking. -
$Filter(i, keep_na = TRUE): return aChunkedArraywith values at positions where logical vector or Arrow boolean-type(Chunked)ArrayiisTRUE. -
$SortIndices(descending = FALSE): return anArrayof integer positions that can be used to rearrange theChunkedArrayin ascending or descending order -
$cast(target_type, safe = TRUE, options = cast_options(safe)): Alter the data in the array to change its type. -
$null_count: The number of null entries in the array -
$chunks: return a list ofArrays -
$num_chunks: integer number of chunks in theChunkedArray -
$type: logical type of data -
$View(type): Construct a zero-copy view of thisChunkedArraywith the given type. -
$Validate(): Perform any validation checks to determine obvious inconsistencies within the array's internal data. This can be an expensive check, potentiallyO(length)
See Also
Array
Examples
# Pass items into chunked_array as separate objects to create chunks
class_scores <- chunked_array(c(87, 88, 89), c(94, 93, 92), c(71, 72, 73))
class_scores$num_chunks
# When taking a Slice from a chunked_array, chunks are preserved
class_scores$Slice(2, length = 5)
# You can combine Take and SortIndices to return a ChunkedArray with 1 chunk
# containing all values, ordered.
class_scores$Take(class_scores$SortIndices(descending = TRUE))
# If you pass a list into chunked_array, you get a list of length 1
list_scores <- chunked_array(list(c(9.9, 9.6, 9.5), c(8.2, 8.3, 8.4), c(10.0, 9.9, 9.8)))
list_scores$num_chunks
# When constructing a ChunkedArray, the first chunk is used to infer type.
doubles <- chunked_array(c(1, 2, 3), c(5L, 6L, 7L))
doubles$type
# Concatenating chunked arrays returns a new chunked array containing all chunks
a <- chunked_array(c(1, 2), 3)
b <- chunked_array(c(4, 5), 6)
c(a, b)
R Package Documentation
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We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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