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<a name="frexp_002c-frexpf_002d_002d_002dsplit-floating_002dpoint-number"></a>
<h3 class="section">1.26 <code>frexp</code>, <code>frexpf</code>&mdash;split floating-point number</h3>
<a name="index-frexp"></a>
<a name="index-frexpf"></a>
<p><strong>Synopsis</strong>
</p><div class="example">
<pre class="example">#include &lt;math.h&gt;
double frexp(double <var>val</var>, int *<var>exp</var>);
float frexpf(float <var>val</var>, int *<var>exp</var>);

</pre></div>
<p><strong>Description</strong><br>
All nonzero, normal numbers can be described as <var>m</var> * 2**<var>p</var>.
<code>frexp</code> represents the double <var>val</var> as a mantissa <var>m</var>
and a power of two <var>p</var>. The resulting mantissa will always
be greater than or equal to <code>0.5</code>, and less than <code>1.0</code> (as
long as <var>val</var> is nonzero). The power of two will be stored
in <code>*</code><var>exp</var>. 
</p>
<p><var>m</var> and <var>p</var> are calculated so that
<var>val</var> is <var>m</var> times <code>2</code> to the power <var>p</var>.
</p>
<p><code>frexpf</code> is identical, other than taking and returning
floats rather than doubles.
</p>
<br>
<p><strong>Returns</strong><br>
<code>frexp</code> returns the mantissa <var>m</var>. If <var>val</var> is <code>0</code>, infinity,
or Nan, <code>frexp</code> will set <code>*</code><var>exp</var> to <code>0</code> and return <var>val</var>.
</p>
<br>
<p><strong>Portability</strong><br>
<code>frexp</code> is ANSI.
<code>frexpf</code> is an extension.
</p>

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