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Next: <a href="Bit-Manipulations.html" accesskey="n" rel="next">Bit Manipulations</a>, Previous: <a href="Single-Precision-Data-Types.html" accesskey="p" rel="prev">Single Precision Data Types</a>, Up: <a href="Numeric-Data-Types.html" accesskey="u" rel="up">Numeric Data Types</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
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<h3 class="section" id="Integer-Data-Types-1"><span>4.4 Integer Data Types<a class="copiable-link" href="#Integer-Data-Types-1"> ¶</a></span></h3>
<p>Octave supports integer matrices as an alternative to using double precision.
It is possible to use both signed and unsigned integers represented by 8, 16,
32, or 64 bits. It should be noted that most computations require floating
point data, meaning that integers will often change type when involved in
numeric computations. For this reason integers are most often used to store
data, and not for calculations.
</p>
<p>In general, most integer matrices are created by casting existing matrices to
integers. The following example shows how to cast a matrix into 32-bit
integers.
</p>
<div class="example">
<div class="group"><pre class="example-preformatted">float = rand (2, 2)
⇒ float = 0.37569 0.92982
0.11962 0.50876
integer = int32 (float)
⇒ integer = 0 1
0 1
</pre></div></div>
<p>As can be seen, floating point values are rounded to the nearest integer when
converted.
</p>
<a class="anchor" id="XREFisinteger"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-isinteger"><span><code class="def-type"><var class="var">tf</var> =</code> <strong class="def-name">isinteger</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-isinteger"> ¶</a></span></dt>
<dd><p>Return true if <var class="var">x</var> is an integer object (int8, uint8, int16, etc.).
</p>
<p>Note that <code class="code">isinteger (14)</code><!-- /@w --> is false because numeric constants in
Octave are double precision floating point values.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="Predicates-for-Numeric-Objects.html#XREFisfloat">isfloat</a>, <a class="ref" href="Character-Arrays.html#XREFischar">ischar</a>, <a class="ref" href="Predicates-for-Numeric-Objects.html#XREFislogical">islogical</a>, <a class="ref" href="Character-Arrays.html#XREFisstring">isstring</a>, <a class="ref" href="Predicates-for-Numeric-Objects.html#XREFisnumeric">isnumeric</a>, <a class="ref" href="Built_002din-Data-Types.html#XREFisa">isa</a>.
</p></dd></dl>
<a class="anchor" id="XREFint8"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-int8"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">int8</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-int8"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to 8-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFint64">int64</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFuint8"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-uint8"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">uint8</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-uint8"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to unsigned 8-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFint64">int64</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFint16"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-int16"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">int16</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-int16"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to 16-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFint64">int64</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFuint16"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-uint16"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">uint16</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-uint16"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to unsigned 16-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFint64">int64</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFint32"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-int32"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">int32</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-int32"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to 32-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFint64">int64</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFuint32"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-uint32"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">uint32</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-uint32"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to unsigned 32-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFint64">int64</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFint64"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-int64"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">int64</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-int64"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to 64-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFuint64">uint64</a>.
</p></dd></dl>
<a class="anchor" id="XREFuint64"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-uint64"><span><code class="def-type"><var class="var">y</var> =</code> <strong class="def-name">uint64</strong> <code class="def-code-arguments">(<var class="var">x</var>)</code><a class="copiable-link" href="#index-uint64"> ¶</a></span></dt>
<dd><p>Convert <var class="var">x</var> to unsigned 64-bit integer type.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFint8">int8</a>, <a class="ref" href="#XREFuint8">uint8</a>, <a class="ref" href="#XREFint16">int16</a>, <a class="ref" href="#XREFuint16">uint16</a>, <a class="ref" href="#XREFint32">int32</a>, <a class="ref" href="#XREFuint32">uint32</a>, <a class="ref" href="#XREFint64">int64</a>.
</p></dd></dl>
<a class="anchor" id="XREFintmax"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-intmax"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">intmax</strong> <code class="def-code-arguments">()</code><a class="copiable-link" href="#index-intmax"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-intmax-1"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">intmax</strong> <code class="def-code-arguments">("<var class="var">type</var>")</code><a class="copiable-link" href="#index-intmax-1"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-intmax-2"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">intmax</strong> <code class="def-code-arguments">(<var class="var">var</var>)</code><a class="copiable-link" href="#index-intmax-2"> ¶</a></span></dt>
<dd><p>Return the largest integer that can be represented by a specific integer type.
</p>
<p>The input is either a string <code class="code">"<var class="var">type</var>"</code> specifying an integer type,
or it is an existing integer variable <var class="var">var</var>.
</p>
<p>Possible values for <var class="var">type</var> are
</p>
<dl class="table">
<dt><code class="code">"int8"</code></dt>
<dd><p>signed 8-bit integer.
</p>
</dd>
<dt><code class="code">"int16"</code></dt>
<dd><p>signed 16-bit integer.
</p>
</dd>
<dt><code class="code">"int32"</code></dt>
<dd><p>signed 32-bit integer.
</p>
</dd>
<dt><code class="code">"int64"</code></dt>
<dd><p>signed 64-bit integer.
</p>
</dd>
<dt><code class="code">"uint8"</code></dt>
<dd><p>unsigned 8-bit integer.
</p>
</dd>
<dt><code class="code">"uint16"</code></dt>
<dd><p>unsigned 16-bit integer.
</p>
</dd>
<dt><code class="code">"uint32"</code></dt>
<dd><p>unsigned 32-bit integer.
</p>
</dd>
<dt><code class="code">"uint64"</code></dt>
<dd><p>unsigned 64-bit integer.
</p></dd>
</dl>
<p>The default for <var class="var">type</var> is <code class="code">"int32"</code>.
</p>
<p>Example Code - query an existing variable
</p>
<div class="example">
<div class="group"><pre class="example-preformatted">x = int8 (1);
intmax (x)
⇒ 127
</pre></div></div>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFintmin">intmin</a>, <a class="ref" href="#XREFflintmax">flintmax</a>.
</p></dd></dl>
<a class="anchor" id="XREFintmin"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-intmin"><span><code class="def-type"><var class="var">Imin</var> =</code> <strong class="def-name">intmin</strong> <code class="def-code-arguments">()</code><a class="copiable-link" href="#index-intmin"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-intmin-1"><span><code class="def-type"><var class="var">Imin</var> =</code> <strong class="def-name">intmin</strong> <code class="def-code-arguments">("<var class="var">type</var>")</code><a class="copiable-link" href="#index-intmin-1"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-intmin-2"><span><code class="def-type"><var class="var">Imin</var> =</code> <strong class="def-name">intmin</strong> <code class="def-code-arguments">(<var class="var">var</var>)</code><a class="copiable-link" href="#index-intmin-2"> ¶</a></span></dt>
<dd><p>Return the smallest integer that can be represented by a specific integer type.
</p>
<p>The input is either a string <code class="code">"<var class="var">type</var>"</code> specifying an integer type,
or it is an existing integer variable <var class="var">var</var>.
</p>
<p>Possible values for <var class="var">type</var> are
</p>
<dl class="table">
<dt><code class="code">"int8"</code></dt>
<dd><p>signed 8-bit integer.
</p>
</dd>
<dt><code class="code">"int16"</code></dt>
<dd><p>signed 16-bit integer.
</p>
</dd>
<dt><code class="code">"int32"</code></dt>
<dd><p>signed 32-bit integer.
</p>
</dd>
<dt><code class="code">"int64"</code></dt>
<dd><p>signed 64-bit integer.
</p>
</dd>
<dt><code class="code">"uint8"</code></dt>
<dd><p>unsigned 8-bit integer.
</p>
</dd>
<dt><code class="code">"uint16"</code></dt>
<dd><p>unsigned 16-bit integer.
</p>
</dd>
<dt><code class="code">"uint32"</code></dt>
<dd><p>unsigned 32-bit integer.
</p>
</dd>
<dt><code class="code">"uint64"</code></dt>
<dd><p>unsigned 64-bit integer.
</p></dd>
</dl>
<p>The default for <var class="var">type</var> is <code class="code">"int32"</code>.
</p>
<p>Example Code - query an existing variable
</p>
<div class="example">
<div class="group"><pre class="example-preformatted">x = int8 (1);
intmin (x)
⇒ -128
</pre></div></div>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFintmax">intmax</a>, <a class="ref" href="#XREFflintmax">flintmax</a>.
</p></dd></dl>
<a class="anchor" id="XREFflintmax"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-flintmax"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">flintmax</strong> <code class="def-code-arguments">()</code><a class="copiable-link" href="#index-flintmax"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-flintmax-1"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">flintmax</strong> <code class="def-code-arguments">("double")</code><a class="copiable-link" href="#index-flintmax-1"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-flintmax-2"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">flintmax</strong> <code class="def-code-arguments">("single")</code><a class="copiable-link" href="#index-flintmax-2"> ¶</a></span></dt>
<dt class="deftypefnx def-cmd-deftypefn" id="index-flintmax-3"><span><code class="def-type"><var class="var">Imax</var> =</code> <strong class="def-name">flintmax</strong> <code class="def-code-arguments">(<var class="var">var</var>)</code><a class="copiable-link" href="#index-flintmax-3"> ¶</a></span></dt>
<dd><p>Return the largest integer that can be represented consecutively in a
floating point value.
</p>
<p>The input is either a string specifying a floating point type, or it is an
existing floating point variable <var class="var">var</var>.
</p>
<p>The default type is <code class="code">"double"</code>, but <code class="code">"single"</code> is a valid option.
On IEEE 754 compatible systems, <code class="code">flintmax</code> is <em class="math">2^{53}</em><!-- /@w --> for
<code class="code">"double"</code> and <em class="math">2^{24}</em><!-- /@w --> for <code class="code">"single"</code>.
</p>
<p>Example Code - query an existing variable
</p>
<div class="example">
<div class="group"><pre class="example-preformatted">x = single (1);
flintmax (x)
⇒ 16777216
</pre></div></div>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFintmax">intmax</a>, <a class="ref" href="Mathematical-Constants.html#XREFrealmax">realmax</a>, <a class="ref" href="Mathematical-Constants.html#XREFrealmin">realmin</a>.
</p></dd></dl>
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<li><a href="Hexadecimal-and-Binary-Integer-Constants.html" accesskey="1">Hexadecimal and Binary Integer Constants</a></li>
<li><a href="Integer-Arithmetic.html" accesskey="2">Integer Arithmetic</a></li>
</ul>
</div>
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