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<h1>Create Arrow data types</h1>
<small class="dont-index">Source: <a href="https://github.com/apache/arrow/blob/main/r/R/type.R" class="external-link"><code>R/type.R</code></a></small>
<div class="d-none name"><code>data-type.Rd</code></div>
</div>
<div class="ref-description section level2">
<p>These functions create type objects corresponding to Arrow types. Use them
when defining a <code><a href="schema.html">schema()</a></code> or as inputs to other types, like <code>struct</code>. Most
of these functions don't take arguments, but a few do.</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">int8</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">int16</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">int32</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">int64</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">uint8</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">uint16</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">uint32</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">uint64</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">float16</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">halffloat</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">float32</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">float</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">float64</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">boolean</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">bool</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">utf8</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">large_utf8</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">binary</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">large_binary</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">fixed_size_binary</span><span class="op">(</span><span class="va">byte_width</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">string</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">date32</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">date64</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">time32</span><span class="op">(</span>unit <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"ms"</span>, <span class="st">"s"</span><span class="op">)</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">time64</span><span class="op">(</span>unit <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"ns"</span>, <span class="st">"us"</span><span class="op">)</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">duration</span><span class="op">(</span>unit <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"s"</span>, <span class="st">"ms"</span>, <span class="st">"us"</span>, <span class="st">"ns"</span><span class="op">)</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">null</span><span class="op">(</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">timestamp</span><span class="op">(</span>unit <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"s"</span>, <span class="st">"ms"</span>, <span class="st">"us"</span>, <span class="st">"ns"</span><span class="op">)</span>, timezone <span class="op">=</span> <span class="st">""</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">decimal</span><span class="op">(</span><span class="va">precision</span>, <span class="va">scale</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">decimal32</span><span class="op">(</span><span class="va">precision</span>, <span class="va">scale</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">decimal64</span><span class="op">(</span><span class="va">precision</span>, <span class="va">scale</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">decimal128</span><span class="op">(</span><span class="va">precision</span>, <span class="va">scale</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">decimal256</span><span class="op">(</span><span class="va">precision</span>, <span class="va">scale</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">struct</span><span class="op">(</span><span class="va">...</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">list_of</span><span class="op">(</span><span class="va">type</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">large_list_of</span><span class="op">(</span><span class="va">type</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">fixed_size_list_of</span><span class="op">(</span><span class="va">type</span>, <span class="va">list_size</span><span class="op">)</span></span>
<span></span>
<span><span class="fu">map_of</span><span class="op">(</span><span class="va">key_type</span>, <span class="va">item_type</span>, .keys_sorted <span class="op">=</span> <span class="cn">FALSE</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 id="arg-byte-width">byte_width<a class="anchor" aria-label="anchor" href="#arg-byte-width"></a></dt>
<dd><p>byte width for <code>FixedSizeBinary</code> type.</p></dd>
<dt id="arg-unit">unit<a class="anchor" aria-label="anchor" href="#arg-unit"></a></dt>
<dd><p>For time/timestamp types, the time unit. <code>time32()</code> can take
either "s" or "ms", while <code>time64()</code> can be "us" or "ns". <code>timestamp()</code> can
take any of those four values.</p></dd>
<dt id="arg-timezone">timezone<a class="anchor" aria-label="anchor" href="#arg-timezone"></a></dt>
<dd><p>For <code>timestamp()</code>, an optional time zone string.</p></dd>
<dt id="arg-precision">precision<a class="anchor" aria-label="anchor" href="#arg-precision"></a></dt>
<dd><p>For <code>decimal()</code>, <code>decimal128()</code>, and <code>decimal256()</code> the
number of significant digits the arrow <code>decimal</code> type can represent. The
maximum precision for <code>decimal128()</code> is 38 significant digits, while for
<code>decimal256()</code> it is 76 digits. <code>decimal()</code> will use it to choose which
type of decimal to return.</p></dd>
<dt id="arg-scale">scale<a class="anchor" aria-label="anchor" href="#arg-scale"></a></dt>
<dd><p>For <code>decimal()</code>, <code>decimal128()</code>, and <code>decimal256()</code> the number
of digits after the decimal point. It can be negative.</p></dd>
<dt id="arg--">...<a class="anchor" aria-label="anchor" href="#arg--"></a></dt>
<dd><p>For <code>struct()</code>, a named list of types to define the struct columns</p></dd>
<dt id="arg-type">type<a class="anchor" aria-label="anchor" href="#arg-type"></a></dt>
<dd><p>For <code>list_of()</code>, a data type to make a list-of-type</p></dd>
<dt id="arg-list-size">list_size<a class="anchor" aria-label="anchor" href="#arg-list-size"></a></dt>
<dd><p>list size for <code>FixedSizeList</code> type.</p></dd>
<dt id="arg-key-type-item-type">key_type, item_type<a class="anchor" aria-label="anchor" href="#arg-key-type-item-type"></a></dt>
<dd><p>For <code>MapType</code>, the key and item types.</p></dd>
<dt id="arg--keys-sorted">.keys_sorted<a class="anchor" aria-label="anchor" href="#arg--keys-sorted"></a></dt>
<dd><p>Use <code>TRUE</code> to assert that keys of a <code>MapType</code> are
sorted.</p></dd>
</dl></div>
<div class="section level2">
<h2 id="value">Value<a class="anchor" aria-label="anchor" href="#value"></a></h2>
<p>An Arrow type object inheriting from <a href="DataType-class.html">DataType</a>.</p>
</div>
<div class="section level2">
<h2 id="details">Details<a class="anchor" aria-label="anchor" href="#details"></a></h2>
<p>A few functions have aliases:</p><ul><li><p><code>utf8()</code> and <code>string()</code></p></li>
<li><p><code>float16()</code> and <code>halffloat()</code></p></li>
<li><p><code>float32()</code> and <code>float()</code></p></li>
<li><p><code>bool()</code> and <code>boolean()</code></p></li>
<li><p>When called inside an <code>arrow</code> function, such as <code><a href="schema.html">schema()</a></code> or <code><a href="cast.html">cast()</a></code>,
<code><a href="https://rdrr.io/r/base/double.html" class="external-link">double()</a></code> also is supported as a way of creating a <code>float64()</code></p></li>
</ul><p><code>date32()</code> creates a datetime type with a "day" unit, like the R <code>Date</code>
class. <code>date64()</code> has a "ms" unit.</p>
<p><code>uint32</code> (32 bit unsigned integer), <code>uint64</code> (64 bit unsigned integer), and
<code>int64</code> (64-bit signed integer) types may contain values that exceed the
range of R's <code>integer</code> type (32-bit signed integer). When these arrow objects
are translated to R objects, <code>uint32</code> and <code>uint64</code> are converted to <code>double</code>
("numeric") and <code>int64</code> is converted to <code><a href="https://rdrr.io/pkg/bit64/man/bit64-package.html" class="external-link">bit64::integer64</a></code>. For <code>int64</code>
types, this conversion can be disabled (so that <code>int64</code> always yields a
<code><a href="https://rdrr.io/pkg/bit64/man/bit64-package.html" class="external-link">bit64::integer64</a></code> object) by setting <code>options(arrow.int64_downcast = FALSE)</code>.</p>
<p><code>decimal128()</code> creates a <code>Decimal128Type</code>. Arrow decimals are fixed-point
decimal numbers encoded as a scalar integer. The <code>precision</code> is the number of
significant digits that the decimal type can represent; the <code>scale</code> is the
number of digits after the decimal point. For example, the number 1234.567
has a precision of 7 and a scale of 3. Note that <code>scale</code> can be negative.</p>
<p>As an example, <code>decimal128(7, 3)</code> can exactly represent the numbers 1234.567 and
-1234.567 (encoded internally as the 128-bit integers 1234567 and -1234567,
respectively), but neither 12345.67 nor 123.4567.</p>
<p><code>decimal128(5, -3)</code> can exactly represent the number 12345000 (encoded
internally as the 128-bit integer 12345), but neither 123450000 nor 1234500.
The <code>scale</code> can be thought of as an argument that controls rounding. When
negative, <code>scale</code> causes the number to be expressed using scientific notation
and power of 10.</p>
<p><code>decimal256()</code> creates a <code>Decimal256Type</code>, which allows for higher maximum
precision. For most use cases, the maximum precision offered by <code>Decimal128Type</code>
is sufficient, and it will result in a more compact and more efficient encoding.</p>
<p><code>decimal()</code> creates either a <code>Decimal128Type</code> or a <code>Decimal256Type</code>
depending on the value for <code>precision</code>. If <code>precision</code> is greater than 38 a
<code>Decimal256Type</code> is returned, otherwise a <code>Decimal128Type</code>.</p>
<p>Use <code>decimal128()</code> or <code>decimal256()</code> as the names are more informative than
<code>decimal()</code>.</p>
</div>
<div class="section level2">
<h2 id="see-also">See also<a class="anchor" aria-label="anchor" href="#see-also"></a></h2>
<div class="dont-index"><p><code><a href="dictionary.html">dictionary()</a></code> for creating a dictionary (factor-like) type.</p></div>
</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="fu">bool</span><span class="op">(</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Boolean</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> bool</span>
<span class="r-in"><span><span class="fu">struct</span><span class="op">(</span>a <span class="op">=</span> <span class="fu">int32</span><span class="op">(</span><span class="op">)</span>, b <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></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> StructType</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> struct&lt;a: int32, b: double&gt;</span>
<span class="r-in"><span><span class="fu">timestamp</span><span class="op">(</span><span class="st">"ms"</span>, timezone <span class="op">=</span> <span class="st">"CEST"</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Timestamp</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> timestamp[ms, tz=CEST]</span>
<span class="r-in"><span><span class="fu">time64</span><span class="op">(</span><span class="st">"ns"</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Time64</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> time64[ns]</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># Use the cast method to change the type of data contained in Arrow objects.</span></span></span>
<span class="r-in"><span><span class="co"># Please check the documentation of each data object class for details.</span></span></span>
<span class="r-in"><span><span class="va">my_scalar</span> <span class="op">&lt;-</span> <span class="va">Scalar</span><span class="op">$</span><span class="fu">create</span><span class="op">(</span><span class="fl">0L</span>, type <span class="op">=</span> <span class="fu">int64</span><span class="op">(</span><span class="op">)</span><span class="op">)</span> <span class="co"># int64</span></span></span>
<span class="r-in"><span><span class="va">my_scalar</span><span class="op">$</span><span class="fu">cast</span><span class="op">(</span><span class="fu">timestamp</span><span class="op">(</span><span class="st">"ns"</span><span class="op">)</span><span class="op">)</span> <span class="co"># timestamp[ns]</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Scalar</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1970-01-01 00:00:00.000000000</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="va">my_array</span> <span class="op">&lt;-</span> <span class="va">Array</span><span class="op">$</span><span class="fu">create</span><span class="op">(</span><span class="fl">0L</span>, type <span class="op">=</span> <span class="fu">int64</span><span class="op">(</span><span class="op">)</span><span class="op">)</span> <span class="co"># int64</span></span></span>
<span class="r-in"><span><span class="va">my_array</span><span class="op">$</span><span class="fu">cast</span><span class="op">(</span><span class="fu">timestamp</span><span class="op">(</span><span class="st">"s"</span>, timezone <span class="op">=</span> <span class="st">"UTC"</span><span class="op">)</span><span class="op">)</span> <span class="co"># timestamp[s, tz=UTC]</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Array</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> &lt;timestamp[s, tz=UTC]&gt;</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1970-01-01 00:00:00Z</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> ]</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="va">my_chunked_array</span> <span class="op">&lt;-</span> <span class="fu"><a href="chunked_array.html">chunked_array</a></span><span class="op">(</span><span class="fl">0L</span>, <span class="fl">1L</span><span class="op">)</span> <span class="co"># int32</span></span></span>
<span class="r-in"><span><span class="va">my_chunked_array</span><span class="op">$</span><span class="fu">cast</span><span class="op">(</span><span class="fu">date32</span><span class="op">(</span><span class="op">)</span><span class="op">)</span> <span class="co"># date32[day]</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> ChunkedArray</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> &lt;date32[day]&gt;</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1970-01-01</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> ],</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1970-01-02</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> ]</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> ]</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># You can also use `cast()` in an Arrow dplyr query.</span></span></span>
<span class="r-in"><span><span class="kw">if</span> <span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/ns-load.html" class="external-link">requireNamespace</a></span><span class="op">(</span><span class="st">"dplyr"</span>, quietly <span class="op">=</span> <span class="cn">TRUE</span><span class="op">)</span><span class="op">)</span> <span class="op">{</span></span></span>
<span class="r-in"><span> <span class="kw"><a href="https://rdrr.io/r/base/library.html" class="external-link">library</a></span><span class="op">(</span><span class="va"><a href="https://dplyr.tidyverse.org" class="external-link">dplyr</a></span>, warn.conflicts <span class="op">=</span> <span class="cn">FALSE</span><span class="op">)</span></span></span>
<span class="r-in"><span> <span class="fu"><a href="table.html">arrow_table</a></span><span class="op">(</span><span class="va">mtcars</span><span class="op">)</span> <span class="op"><a href="https://magrittr.tidyverse.org/reference/pipe.html" class="external-link">%&gt;%</a></span></span></span>
<span class="r-in"><span> <span class="fu"><a href="https://dplyr.tidyverse.org/reference/transmute.html" class="external-link">transmute</a></span><span class="op">(</span></span></span>
<span class="r-in"><span> col1 <span class="op">=</span> <span class="fu"><a href="cast.html">cast</a></span><span class="op">(</span><span class="va">cyl</span>, <span class="fu">string</span><span class="op">(</span><span class="op">)</span><span class="op">)</span>,</span></span>
<span class="r-in"><span> col2 <span class="op">=</span> <span class="fu"><a href="cast.html">cast</a></span><span class="op">(</span><span class="va">cyl</span>, <span class="fu">int8</span><span class="op">(</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-in"><span> <span class="op">)</span> <span class="op"><a href="https://magrittr.tidyverse.org/reference/pipe.html" class="external-link">%&gt;%</a></span></span></span>
<span class="r-in"><span> <span class="fu"><a href="https://dplyr.tidyverse.org/reference/compute.html" class="external-link">compute</a></span><span class="op">(</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="op">}</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Table</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 32 rows x 2 columns</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> $col1 &lt;string&gt;</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> $col2 &lt;int8&gt;</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> See $metadata for additional Schema metadata</span>
</code></pre></div>
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