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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/arrow/r/man/array.Rd | |
parent | Initial commit. (diff) | |
download | ceph-b26c4052f3542036551aa9dec9caa4226e456195.tar.xz ceph-b26c4052f3542036551aa9dec9caa4226e456195.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/arrow/r/man/array.Rd')
-rw-r--r-- | src/arrow/r/man/array.Rd | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/arrow/r/man/array.Rd b/src/arrow/r/man/array.Rd new file mode 100644 index 000000000..78d3eaff6 --- /dev/null +++ b/src/arrow/r/man/array.Rd @@ -0,0 +1,107 @@ +% Generated by roxygen2: do not edit by hand +% Please edit documentation in R/array.R, R/scalar.R +\docType{class} +\name{array} +\alias{array} +\alias{Array} +\alias{DictionaryArray} +\alias{StructArray} +\alias{ListArray} +\alias{LargeListArray} +\alias{FixedSizeListArray} +\alias{StructScalar} +\title{Arrow Arrays} +\description{ +An \code{Array} is an immutable data array with some logical type +and some length. Most logical types are contained in the base +\code{Array} class; there are also subclasses for \code{DictionaryArray}, \code{ListArray}, +and \code{StructArray}. +} +\section{Factory}{ + +The \code{Array$create()} factory method instantiates an \code{Array} and +takes the following arguments: +\itemize{ +\item \code{x}: an R vector, list, or \code{data.frame} +\item \code{type}: an optional \link[=data-type]{data type} for \code{x}. If omitted, the type +will be inferred from the data. +} + +\code{Array$create()} will return the appropriate subclass of \code{Array}, such as +\code{DictionaryArray} when given an R factor. + +To compose a \code{DictionaryArray} directly, call \code{DictionaryArray$create()}, +which takes two arguments: +\itemize{ +\item \code{x}: an R vector or \code{Array} of integers for the dictionary indices +\item \code{dict}: an R vector or \code{Array} of dictionary values (like R factor levels +but not limited to strings only) +} +} + +\section{Usage}{ +\preformatted{a <- Array$create(x) +length(a) + +print(a) +a == a +} +} + +\section{Methods}{ + +\itemize{ +\item \verb{$IsNull(i)}: Return true if value at index is null. Does not boundscheck +\item \verb{$IsValid(i)}: Return true if value at index is valid. Does not boundscheck +\item \verb{$length()}: Size in the number of elements this array contains +\item \verb{$offset}: A relative position into another array's data, to enable zero-copy slicing +\item \verb{$null_count}: The number of null entries in the array +\item \verb{$type}: logical type of data +\item \verb{$type_id()}: type id +\item \verb{$Equals(other)} : is this array equal to \code{other} +\item \verb{$ApproxEquals(other)} : +\item \verb{$Diff(other)} : return a string expressing the difference between two arrays +\item \verb{$data()}: return the underlying \link{ArrayData} +\item \verb{$as_vector()}: convert to an R vector +\item \verb{$ToString()}: string representation of the array +\item \verb{$Slice(offset, length = NULL)}: Construct a zero-copy slice of the array +with the indicated offset and length. If length is \code{NULL}, the slice goes +until the end of the array. +\item \verb{$Take(i)}: return an \code{Array} with values at positions given by integers +(R vector or Array Array) \code{i}. +\item \verb{$Filter(i, keep_na = TRUE)}: return an \code{Array} with values at positions where logical +vector (or Arrow boolean Array) \code{i} is \code{TRUE}. +\item \verb{$SortIndices(descending = FALSE)}: return an \code{Array} of integer positions that can be +used to rearrange the \code{Array} in ascending or descending order +\item \verb{$RangeEquals(other, start_idx, end_idx, other_start_idx)} : +\item \verb{$cast(target_type, safe = TRUE, options = cast_options(safe))}: Alter the +data in the array to change its type. +\item \verb{$View(type)}: Construct a zero-copy view of this array with the given type. +\item \verb{$Validate()} : Perform any validation checks to determine obvious inconsistencies +within the array's internal data. This can be an expensive check, potentially \code{O(length)} +} +} + +\examples{ +\dontshow{if (arrow_available()) (if (getRversion() >= "3.4") withAutoprint else force)(\{ # examplesIf} +my_array <- Array$create(1:10) +my_array$type +my_array$cast(int8()) + +# Check if value is null; zero-indexed +na_array <- Array$create(c(1:5, NA)) +na_array$IsNull(0) +na_array$IsNull(5) +na_array$IsValid(5) +na_array$null_count + +# zero-copy slicing; the offset of the new Array will be the same as the index passed to $Slice +new_array <- na_array$Slice(5) +new_array$offset + +# Compare 2 arrays +na_array2 <- na_array +na_array2 == na_array # element-wise comparison +na_array2$Equals(na_array) # overall comparison +\dontshow{\}) # examplesIf} +} |