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<a name="catan_002c-catanf_002d_002d_002dcomplex-arc-tangent"></a>
<h3 class="section">2.7 <code>catan</code>, <code>catanf</code>—complex arc tangent</h3>
<a name="index-catan"></a>
<a name="index-catanf"></a>
<p><strong>Synopsis</strong>
</p><div class="example">
<pre class="example">#include <complex.h>
double complex catan(double complex <var>z</var>);
float complex catanf(float complex <var>z</var>);
</pre></div>
<p><strong>Description</strong><br>
These functions compute the complex arc tangent of <var>z</var>,
with branch cuts outside the interval [-i, +i] along the
imaginary axis.
</p>
<p><code>catanf</code> is identical to <code>catan</code>, except that it performs
its calculations on <code>floats complex</code>.
</p>
<br>
<p><strong>Returns</strong><br>
These functions return the complex arc tangent value, in the range
of a strip mathematically unbounded along the imaginary axis
and in the interval [-pi/2, +pi/2] along the real axis.
</p>
<br>
<p><strong>Portability</strong><br>
<code>catan</code> and <code>catanf</code> are ISO C99
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