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| # distributed with this work for additional information |
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| # to you under the Apache License, Version 2.0 (the |
| # "License"); you may not use this file except in compliance |
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| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, |
| # software distributed under the License is distributed on an |
| # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| # KIND, either express or implied. See the License for the |
| # specific language governing permissions and limitations |
| # under the License. |
| |
| #' @include arrow-datum.R |
| |
| #' @title ChunkedArray class |
| #' @usage NULL |
| #' @format NULL |
| #' @docType class |
| #' @description A `ChunkedArray` is a data structure managing a list of |
| #' primitive Arrow [Arrays][Array] logically as one large array. Chunked arrays |
| #' may be grouped together in a [Table]. |
| #' @section Factory: |
| #' The `ChunkedArray$create()` factory method instantiates the object from |
| #' various Arrays or R vectors. `chunked_array()` is an alias for it. |
| #' |
| #' @section Methods: |
| #' |
| #' - `$length()`: Size in the number of elements this array contains |
| #' - `$chunk(i)`: Extract an `Array` chunk by integer position |
| #' - `$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 |
| #' - `$chunks`: return a list of `Array`s |
| #' - `$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. |
| #' - `$Validate()`: Perform any validation checks to determine obvious inconsistencies |
| #' within the array's internal data. This can be an expensive check, potentially `O(length)` |
| #' |
| #' @rdname ChunkedArray |
| #' @name ChunkedArray |
| #' @seealso [Array] |
| #' @examplesIf arrow_available() |
| #' # Pass items into chunked_array as separate objects to create chunks |
| #' class_scores <- chunked_array(c(87, 88, 89), c(94, 93, 92), c(71, 72, 73)) |
| #' class_scores$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$type |
| #' @export |
| ChunkedArray <- R6Class("ChunkedArray", inherit = ArrowDatum, |
| public = list( |
| length = function() ChunkedArray__length(self), |
| type_id = function() ChunkedArray__type(self)$id, |
| chunk = function(i) Array$create(ChunkedArray__chunk(self, i)), |
| as_vector = function() ChunkedArray__as_vector(self, option_use_threads()), |
| Slice = function(offset, length = NULL) { |
| if (is.null(length)) { |
| ChunkedArray__Slice1(self, offset) |
| } else { |
| ChunkedArray__Slice2(self, offset, length) |
| } |
| }, |
| Take = function(i) { |
| if (is.numeric(i)) { |
| i <- as.integer(i) |
| } |
| if (is.integer(i)) { |
| i <- Array$create(i) |
| } |
| call_function("take", self, i) |
| }, |
| Filter = function(i, keep_na = TRUE) { |
| if (is.logical(i)) { |
| i <- Array$create(i) |
| } |
| call_function("filter", self, i, options = list(keep_na = keep_na)) |
| }, |
| SortIndices = function(descending = FALSE) { |
| assert_that(is.logical(descending)) |
| assert_that(length(descending) == 1L) |
| assert_that(!is.na(descending)) |
| # TODO: after ARROW-12042 is closed, review whether this and the |
| # Array$SortIndices definition can be consolidated |
| call_function( |
| "sort_indices", |
| self, |
| options = list(names = "", orders = as.integer(descending)) |
| ) |
| }, |
| View = function(type) { |
| ChunkedArray__View(self, as_type(type)) |
| }, |
| Validate = function() { |
| ChunkedArray__Validate(self) |
| }, |
| ToString = function() { |
| ChunkedArray__ToString(self) |
| }, |
| Equals = function(other, ...) { |
| inherits(other, "ChunkedArray") && ChunkedArray__Equals(self, other) |
| } |
| ), |
| active = list( |
| null_count = function() ChunkedArray__null_count(self), |
| num_chunks = function() ChunkedArray__num_chunks(self), |
| chunks = function() map(ChunkedArray__chunks(self), Array$create), |
| type = function() ChunkedArray__type(self) |
| ) |
| ) |
| |
| ChunkedArray$create <- function(..., type = NULL) { |
| if (!is.null(type)) { |
| type <- as_type(type) |
| } |
| ChunkedArray__from_list(list2(...), type) |
| } |
| |
| #' @param \dots Vectors to coerce |
| #' @param type currently ignored |
| #' @rdname ChunkedArray |
| #' @export |
| chunked_array <- ChunkedArray$create |