blob: b1c6cefe9b4c3222968efb3ee69d7e323d1aba4d [file] [log] [blame]
<!DOCTYPE html>
<!-- Generated by pkgdown: do not edit by hand --><html lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"><meta name="description" content="Converts array to the type specified by to. This is a low-level interface;
most users should use as.data.frame() or as.vector() unless finer-grained
control is needed over the conversion. This function is an S3 generic
dispatching on to: developers may implement their own S3 methods for
custom vector types."><title>Convert an Array into an R vector — convert_array • nanoarrow</title><script src="../deps/jquery-3.6.0/jquery-3.6.0.min.js"></script><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"><link href="../deps/bootstrap-5.3.1/bootstrap.min.css" rel="stylesheet"><script src="../deps/bootstrap-5.3.1/bootstrap.bundle.min.js"></script><!-- Font Awesome icons --><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/all.min.css" integrity="sha256-mmgLkCYLUQbXn0B1SRqzHar6dCnv9oZFPEC1g1cwlkk=" crossorigin="anonymous"><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/v4-shims.min.css" integrity="sha256-wZjR52fzng1pJHwx4aV2AO3yyTOXrcDW7jBpJtTwVxw=" crossorigin="anonymous"><!-- bootstrap-toc --><script src="https://cdn.jsdelivr.net/gh/afeld/bootstrap-toc@v1.0.1/dist/bootstrap-toc.min.js" integrity="sha256-4veVQbu7//Lk5TSmc7YV48MxtMy98e26cf5MrgZYnwo=" crossorigin="anonymous"></script><!-- headroom.js --><script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/headroom.min.js" integrity="sha256-AsUX4SJE1+yuDu5+mAVzJbuYNPHj/WroHuZ8Ir/CkE0=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/jQuery.headroom.min.js" integrity="sha256-ZX/yNShbjqsohH1k95liqY9Gd8uOiE1S4vZc+9KQ1K4=" crossorigin="anonymous"></script><!-- clipboard.js --><script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.11/clipboard.min.js" integrity="sha512-7O5pXpc0oCRrxk8RUfDYFgn0nO1t+jLuIOQdOMRp4APB7uZ4vSjspzp5y6YDtDs4VzUSTbWzBFZ/LKJhnyFOKw==" crossorigin="anonymous" referrerpolicy="no-referrer"></script><!-- search --><script src="https://cdnjs.cloudflare.com/ajax/libs/fuse.js/6.4.6/fuse.js" integrity="sha512-zv6Ywkjyktsohkbp9bb45V6tEMoWhzFzXis+LrMehmJZZSys19Yxf1dopHx7WzIKxr5tK2dVcYmaCk2uqdjF4A==" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/autocomplete.js/0.38.0/autocomplete.jquery.min.js" integrity="sha512-GU9ayf+66Xx2TmpxqJpliWbT5PiGYxpaG8rfnBEk1LL8l1KGkRShhngwdXK1UgqhAzWpZHSiYPc09/NwDQIGyg==" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/mark.js/8.11.1/mark.min.js" integrity="sha512-5CYOlHXGh6QpOFA/TeTylKLWfB3ftPsde7AnmhuitiTX4K5SqCLBeKro6sPS8ilsz1Q4NRx3v8Ko2IBiszzdww==" crossorigin="anonymous"></script><!-- pkgdown --><script src="../pkgdown.js"></script><meta property="og:title" content="Convert an Array into an R vector — convert_array"><meta property="og:description" content="Converts array to the type specified by to. This is a low-level interface;
most users should use as.data.frame() or as.vector() unless finer-grained
control is needed over the conversion. This function is an S3 generic
dispatching on to: developers may implement their own S3 methods for
custom vector types."><!-- mathjax --><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js" integrity="sha256-nvJJv9wWKEm88qvoQl9ekL2J+k/RWIsaSScxxlsrv8k=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/config/TeX-AMS-MML_HTMLorMML.js" integrity="sha256-84DKXVJXs0/F8OTMzX4UR909+jtl4G7SPypPavF+GfA=" crossorigin="anonymous"></script><!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]--></head><body>
<a href="#main" class="visually-hidden-focusable">Skip to contents</a>
<nav class="navbar fixed-top navbar-light navbar-expand-lg bg-light" data-bs-theme="light"><div class="container">
<a class="navbar-brand me-2" href="../index.html">nanoarrow</a>
<small class="nav-text text-muted me-auto" data-bs-toggle="tooltip" data-bs-placement="bottom" title="">0.5.0.9000</small>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbar" aria-controls="navbar" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div id="navbar" class="collapse navbar-collapse ms-3">
<ul class="navbar-nav me-auto"><li class="active nav-item">
<a class="nav-link" href="../reference/index.html">Reference</a>
</li>
<li class="nav-item">
<a class="nav-link" href="../news/index.html">Changelog</a>
</li>
</ul><form class="form-inline my-2 my-lg-0" role="search">
<input type="search" class="form-control me-sm-2" aria-label="Toggle navigation" name="search-input" data-search-index="../search.json" id="search-input" placeholder="Search for" autocomplete="off"></form>
<ul class="navbar-nav"><li class="nav-item">
<a class="external-link nav-link" href="https://github.com/apache/arrow-nanoarrow/" aria-label="github">
<span class="fab fa fab fa-github fa-lg"></span>
</a>
</li>
</ul></div>
</div>
</nav><div class="container template-reference-topic">
<div class="row">
<main id="main" class="col-md-9"><div class="page-header">
<img src="" class="logo" alt=""><h1>Convert an Array into an R vector</h1>
<small class="dont-index">Source: <a href="https://github.com/apache/arrow-nanoarrow/blob/main/r/R/convert-array.R" class="external-link"><code>R/convert-array.R</code></a></small>
<div class="d-none name"><code>convert_array.Rd</code></div>
</div>
<div class="ref-description section level2">
<p>Converts <code>array</code> to the type specified by <code>to</code>. This is a low-level interface;
most users should use <code><a href="https://rdrr.io/r/base/as.data.frame.html" class="external-link">as.data.frame()</a></code> or <code><a href="https://rdrr.io/r/base/vector.html" class="external-link">as.vector()</a></code> unless finer-grained
control is needed over the conversion. This function is an S3 generic
dispatching on <code>to</code>: developers may implement their own S3 methods for
custom vector types.</p>
</div>
<div class="section level2">
<h2 id="ref-usage">Usage<a class="anchor" aria-label="anchor" href="#ref-usage"></a></h2>
<div class="sourceCode"><pre class="sourceCode r"><code><span><span class="fu">convert_array</span><span class="op">(</span><span class="va">array</span>, to <span class="op">=</span> <span class="cn">NULL</span>, <span class="va">...</span><span class="op">)</span></span></code></pre></div>
</div>
<div class="section level2">
<h2 id="arguments">Arguments<a class="anchor" aria-label="anchor" href="#arguments"></a></h2>
<dl><dt>array</dt>
<dd><p>A <a href="as_nanoarrow_array.html">nanoarrow_array</a>.</p></dd>
<dt>to</dt>
<dd><p>A target prototype object describing the type to which <code>array</code>
should be converted, or <code>NULL</code> to use the default conversion as
returned by <code><a href="infer_nanoarrow_ptype.html">infer_nanoarrow_ptype()</a></code>. Alternatively, a function can be
passed to perform an alternative calculation of the default ptype as
a function of <code>array</code> and the default inference of the prototype.</p></dd>
<dt>...</dt>
<dd><p>Passed to S3 methods</p></dd>
</dl></div>
<div class="section level2">
<h2 id="value">Value<a class="anchor" aria-label="anchor" href="#value"></a></h2>
<p>An R vector of type <code>to</code>.</p>
</div>
<div class="section level2">
<h2 id="details">Details<a class="anchor" aria-label="anchor" href="#details"></a></h2>
<p>Conversions are implemented for the following R vector types:</p><ul><li><p><code><a href="https://rdrr.io/r/base/logical.html" class="external-link">logical()</a></code>: Any numeric type can be converted to <code><a href="https://rdrr.io/r/base/logical.html" class="external-link">logical()</a></code> in addition
to the bool type. For numeric types, any non-zero value is considered <code>TRUE</code>.</p></li>
<li><p><code><a href="https://rdrr.io/r/base/integer.html" class="external-link">integer()</a></code>: Any numeric type can be converted to <code><a href="https://rdrr.io/r/base/integer.html" class="external-link">integer()</a></code>; however,
a warning will be signaled if the any value is outside the range of the
32-bit integer.</p></li>
<li><p><code><a href="https://rdrr.io/r/base/double.html" class="external-link">double()</a></code>: Any numeric type can be converted to <code><a href="https://rdrr.io/r/base/double.html" class="external-link">double()</a></code>. This
conversion currently does not warn for values that may not roundtrip
through a floating-point double (e.g., very large uint64 and int64 values).</p></li>
<li><p><code><a href="https://rdrr.io/r/base/character.html" class="external-link">character()</a></code>: String and large string types can be converted to
<code><a href="https://rdrr.io/r/base/character.html" class="external-link">character()</a></code>. The conversion does not check for valid UTF-8: if you need
finer-grained control over encodings, use <code>to = blob::blob()</code>.</p></li>
<li><p><code><a href="https://rdrr.io/r/base/factor.html" class="external-link">factor()</a></code>: Dictionary-encoded arrays of strings can be converted to
<code><a href="https://rdrr.io/r/base/factor.html" class="external-link">factor()</a></code>; however, this must be specified explicitly (i.e.,
<code>convert_array(array, factor())</code>) because arrays arriving
in chunks can have dictionaries that contain different levels. Use
<code>convert_array(array, factor(levels = c(...)))</code> to materialize an array
into a vector with known levels.</p></li>
<li><p><a href="https://rdrr.io/r/base/as.Date.html" class="external-link">Date</a>: Only the date32 type can be converted to an R Date vector.</p></li>
<li><p><code><a href="https://hms.tidyverse.org/reference/hms.html" class="external-link">hms::hms()</a></code>: Time32 and time64 types can be converted to <code><a href="https://hms.tidyverse.org/reference/hms.html" class="external-link">hms::hms()</a></code>.</p></li>
<li><p><code><a href="https://rdrr.io/r/base/difftime.html" class="external-link">difftime()</a></code>: Time32, time64, and duration types can be converted to
R <code><a href="https://rdrr.io/r/base/difftime.html" class="external-link">difftime()</a></code> vectors. The value is converted to match the <code><a href="https://rdrr.io/r/base/units.html" class="external-link">units()</a></code>
attribute of <code>to</code>.</p></li>
<li><p><code><a href="https://blob.tidyverse.org/reference/blob.html" class="external-link">blob::blob()</a></code>: String, large string, binary, and large binary types can
be converted to <code><a href="https://blob.tidyverse.org/reference/blob.html" class="external-link">blob::blob()</a></code>.</p></li>
<li><p><code><a href="https://vctrs.r-lib.org/reference/list_of.html" class="external-link">vctrs::list_of()</a></code>: List, large list, and fixed-size list types can be
converted to <code><a href="https://vctrs.r-lib.org/reference/list_of.html" class="external-link">vctrs::list_of()</a></code>.</p></li>
<li><p><code><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame()</a></code>: Struct types can be converted to <code><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame()</a></code>.</p></li>
<li><p><code><a href="https://vctrs.r-lib.org/reference/unspecified.html" class="external-link">vctrs::unspecified()</a></code>: Any type can be converted to <code><a href="https://vctrs.r-lib.org/reference/unspecified.html" class="external-link">vctrs::unspecified()</a></code>;
however, a warning will be raised if any non-null values are encountered.</p></li>
</ul><p>In addition to the above conversions, a null array may be converted to any
target prototype except <code><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame()</a></code>. Extension arrays are currently
converted as their storage type.</p>
</div>
<div class="section level2">
<h2 id="ref-examples">Examples<a class="anchor" aria-label="anchor" href="#ref-examples"></a></h2>
<div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span><span class="va">array</span> <span class="op">&lt;-</span> <span class="fu"><a href="as_nanoarrow_array.html">as_nanoarrow_array</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span>x <span class="op">=</span> <span class="fl">1</span><span class="op">:</span><span class="fl">5</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/str.html" class="external-link">str</a></span><span class="op">(</span><span class="fu">convert_array</span><span class="op">(</span><span class="va">array</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 'data.frame': 5 obs. of 1 variable:</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> $ x: int 1 2 3 4 5</span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/str.html" class="external-link">str</a></span><span class="op">(</span><span class="fu">convert_array</span><span class="op">(</span><span class="va">array</span>, to <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span>x <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/double.html" class="external-link">double</a></span><span class="op">(</span><span class="op">)</span><span class="op">)</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 'data.frame': 5 obs. of 1 variable:</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> $ x: num 1 2 3 4 5</span>
<span class="r-in"><span></span></span>
</code></pre></div>
</div>
</main><aside class="col-md-3"><nav id="toc"><h2>On this page</h2>
</nav></aside></div>
<footer><div class="pkgdown-footer-left">
<p>Developed by Dewey Dunnington, Apache Arrow.</p>
</div>
<div class="pkgdown-footer-right">
<p>Site built with <a href="https://pkgdown.r-lib.org/" class="external-link">pkgdown</a> 2.0.9.</p>
</div>
</footer></div>
</body></html>