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<h3 class="section" id="Comparison-Operators"><span>8.4 Comparison Operators<a class="copiable-link" href="#Comparison-Operators"> ¶</a></span></h3>
<a class="index-entry-id" id="index-comparison-expressions"></a>
<a class="index-entry-id" id="index-expressions_002c-comparison"></a>
<a class="index-entry-id" id="index-relational-operators"></a>
<a class="index-entry-id" id="index-operators_002c-relational"></a>
<a class="index-entry-id" id="index-less-than-operator"></a>
<a class="index-entry-id" id="index-greater-than-operator"></a>
<a class="index-entry-id" id="index-equality-operator"></a>
<a class="index-entry-id" id="index-tests-for-equality"></a>
<a class="index-entry-id" id="index-equality_002c-tests-for"></a>
<p><em class="dfn">Comparison operators</em> compare numeric values for relationships
such as equality. They are written using
<em class="emph">relational operators</em>.
</p>
<p>All of Octave’s comparison operators return a value of 1 if the
comparison is true, or 0 if it is false. For matrix values, they all
work on an element-by-element basis. Broadcasting rules apply.
See <a class="xref" href="Broadcasting.html">Broadcasting</a>. For example:
</p>
<div class="example">
<div class="group"><pre class="example-preformatted">[1, 2; 3, 4] == [1, 3; 2, 4]
⇒ 1 0
0 1
</pre></div></div>
<p>According to broadcasting rules, if one operand is a scalar and the
other is a matrix, the scalar is compared to each element of the matrix
in turn, and the result is the same size as the matrix.
</p>
<dl class="table">
<dt><a id="index-_003c"></a><span><code class="code"><var class="var">x</var> < <var class="var">y</var></code><a class="copiable-link" href="#index-_003c"> ¶</a></span></dt>
<dd><p>True if <var class="var">x</var> is less than <var class="var">y</var>.
</p>
</dd>
<dt><a id="index-_003c_003d"></a><span><code class="code"><var class="var">x</var> <= <var class="var">y</var></code><a class="copiable-link" href="#index-_003c_003d"> ¶</a></span></dt>
<dd><p>True if <var class="var">x</var> is less than or equal to <var class="var">y</var>.
</p>
</dd>
<dt><a id="index-_003d_003d"></a><span><code class="code"><var class="var">x</var> == <var class="var">y</var></code><a class="copiable-link" href="#index-_003d_003d"> ¶</a></span></dt>
<dd><p>True if <var class="var">x</var> is equal to <var class="var">y</var>.
</p>
</dd>
<dt><a id="index-_003e_003d"></a><span><code class="code"><var class="var">x</var> >= <var class="var">y</var></code><a class="copiable-link" href="#index-_003e_003d"> ¶</a></span></dt>
<dd><p>True if <var class="var">x</var> is greater than or equal to <var class="var">y</var>.
</p>
</dd>
<dt><a id="index-_003e"></a><span><code class="code"><var class="var">x</var> > <var class="var">y</var></code><a class="copiable-link" href="#index-_003e"> ¶</a></span></dt>
<dd><p>True if <var class="var">x</var> is greater than <var class="var">y</var>.
</p>
</dd>
<dt><a class="index-entry-id" id="index-_007e_003d"></a>
<a id="index-_0021_003d"></a><span><code class="code"><var class="var">x</var> != <var class="var">y</var></code><a class="copiable-link" href="#index-_0021_003d"> ¶</a></span></dt>
<dt><code class="code"><var class="var">x</var> ~= <var class="var">y</var></code></dt>
<dd><p>True if <var class="var">x</var> is not equal to <var class="var">y</var>.
</p></dd>
</dl>
<p>For complex numbers, the following ordering is defined:
<var class="var">z1</var> < <var class="var">z2</var>
if and only if
</p>
<div class="example">
<div class="group"><pre class="example-preformatted"> abs (<var class="var">z1</var>) < abs (<var class="var">z2</var>)
|| (abs (<var class="var">z1</var>) == abs (<var class="var">z2</var>) && arg (<var class="var">z1</var>) < arg (<var class="var">z2</var>))
</pre></div></div>
<p>This is consistent with the ordering used by <em class="dfn">max</em>, <em class="dfn">min</em> and
<em class="dfn">sort</em>, but is not consistent with <small class="sc">MATLAB</small>, which only compares the real
parts.
</p>
<p>String comparisons may also be performed with the <code class="code">strcmp</code>
function, not with the comparison operators listed above.
See <a class="xref" href="Strings.html">Strings</a>.
</p>
<a class="index-entry-id" id="index-_003d_003d-1"></a>
<a class="anchor" id="XREFeq"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-eq"><span><code class="def-type"><var class="var">TF</var> =</code> <strong class="def-name">eq</strong> <code class="def-code-arguments">(<var class="var">A</var>, <var class="var">B</var>)</code><a class="copiable-link" href="#index-eq"> ¶</a></span></dt>
<dd><p>Return true if the two inputs are equal.
</p>
<p>This function is equivalent to <code class="code"><var class="var">A</var> == <var class="var">B</var></code><!-- /@w -->.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFne">ne</a>, <a class="ref" href="#XREFisequal">isequal</a>, <a class="ref" href="#XREFle">le</a>, <a class="ref" href="#XREFge">ge</a>, <a class="ref" href="#XREFgt">gt</a>, <a class="ref" href="#XREFne">ne</a>, <a class="ref" href="#XREFlt">lt</a>.
</p></dd></dl>
<a class="index-entry-id" id="index-_003e_003d-1"></a>
<a class="anchor" id="XREFge"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-ge"><span><code class="def-type"><var class="var">TF</var> =</code> <strong class="def-name">ge</strong> <code class="def-code-arguments">(<var class="var">A</var>, <var class="var">B</var>)</code><a class="copiable-link" href="#index-ge"> ¶</a></span></dt>
<dd><p>This function is equivalent to <code class="code"><var class="var">A</var> >= <var class="var">B</var></code><!-- /@w -->.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFle">le</a>, <a class="ref" href="#XREFeq">eq</a>, <a class="ref" href="#XREFgt">gt</a>, <a class="ref" href="#XREFne">ne</a>, <a class="ref" href="#XREFlt">lt</a>.
</p></dd></dl>
<a class="index-entry-id" id="index-_003e-1"></a>
<a class="anchor" id="XREFgt"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-gt"><span><code class="def-type"><var class="var">TF</var> =</code> <strong class="def-name">gt</strong> <code class="def-code-arguments">(<var class="var">A</var>, <var class="var">B</var>)</code><a class="copiable-link" href="#index-gt"> ¶</a></span></dt>
<dd><p>This function is equivalent to <code class="code"><var class="var">A</var> > <var class="var">B</var></code><!-- /@w -->.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFle">le</a>, <a class="ref" href="#XREFeq">eq</a>, <a class="ref" href="#XREFge">ge</a>, <a class="ref" href="#XREFne">ne</a>, <a class="ref" href="#XREFlt">lt</a>.
</p></dd></dl>
<a class="anchor" id="XREFisequal"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-isequal"><span><code class="def-type"><var class="var">tf</var> =</code> <strong class="def-name">isequal</strong> <code class="def-code-arguments">(<var class="var">x1</var>, <var class="var">x2</var>, …)</code><a class="copiable-link" href="#index-isequal"> ¶</a></span></dt>
<dd><p>Return true if all of <var class="var">x1</var>, <var class="var">x2</var>, … are equal.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFisequaln">isequaln</a>.
</p></dd></dl>
<a class="anchor" id="XREFisequaln"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-isequaln"><span><code class="def-type"><var class="var">tf</var> =</code> <strong class="def-name">isequaln</strong> <code class="def-code-arguments">(<var class="var">x1</var>, <var class="var">x2</var>, …)</code><a class="copiable-link" href="#index-isequaln"> ¶</a></span></dt>
<dd><p>Return true if all of <var class="var">x1</var>, <var class="var">x2</var>, … are equal under the
additional assumption that NaN == NaN (no comparison of NaN placeholders
in dataset).
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFisequal">isequal</a>.
</p></dd></dl>
<a class="index-entry-id" id="index-_003c_003d-1"></a>
<a class="anchor" id="XREFle"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-le"><span><code class="def-type"><var class="var">TF</var> =</code> <strong class="def-name">le</strong> <code class="def-code-arguments">(<var class="var">A</var>, <var class="var">B</var>)</code><a class="copiable-link" href="#index-le"> ¶</a></span></dt>
<dd><p>This function is equivalent to <code class="code"><var class="var">A</var> <= <var class="var">B</var></code><!-- /@w -->.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFeq">eq</a>, <a class="ref" href="#XREFge">ge</a>, <a class="ref" href="#XREFgt">gt</a>, <a class="ref" href="#XREFne">ne</a>, <a class="ref" href="#XREFlt">lt</a>.
</p></dd></dl>
<a class="index-entry-id" id="index-_003c-1"></a>
<a class="anchor" id="XREFlt"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-lt"><span><code class="def-type"><var class="var">TF</var> =</code> <strong class="def-name">lt</strong> <code class="def-code-arguments">(<var class="var">A</var>, <var class="var">B</var>)</code><a class="copiable-link" href="#index-lt"> ¶</a></span></dt>
<dd><p>This function is equivalent to <code class="code"><var class="var">A</var> < <var class="var">B</var></code><!-- /@w -->.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFle">le</a>, <a class="ref" href="#XREFeq">eq</a>, <a class="ref" href="#XREFge">ge</a>, <a class="ref" href="#XREFgt">gt</a>, <a class="ref" href="#XREFne">ne</a>.
</p></dd></dl>
<a class="index-entry-id" id="index-_0021_003d-1"></a>
<a class="index-entry-id" id="index-_007e_003d-1"></a>
<a class="anchor" id="XREFne"></a><span style="display:block; margin-top:-4.5ex;"> </span>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-ne"><span><code class="def-type"><var class="var">TF</var> =</code> <strong class="def-name">ne</strong> <code class="def-code-arguments">(<var class="var">A</var>, <var class="var">B</var>)</code><a class="copiable-link" href="#index-ne"> ¶</a></span></dt>
<dd><p>Return true if the two inputs are not equal.
</p>
<p>This function is equivalent to <code class="code"><var class="var">A</var> != <var class="var">B</var></code><!-- /@w -->.
</p>
<p><strong class="strong">See also:</strong> <a class="ref" href="#XREFeq">eq</a>, <a class="ref" href="#XREFisequal">isequal</a>, <a class="ref" href="#XREFle">le</a>, <a class="ref" href="#XREFge">ge</a>, <a class="ref" href="#XREFlt">lt</a>.
</p></dd></dl>
</div>
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