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<h3 class="section">4.5 Testing the Sign of Numbers</h3>
<div class="defun">
— Macro: <b>GSL_SIGN</b> (<var>x</var>)<var><a name="index-GSL_005fSIGN-119"></a></var><br>
<blockquote><p>This macro returns the sign of <var>x</var>. It is defined as <code>((x) >= 0
? 1 : -1)</code>. Note that with this definition the sign of zero is positive
(regardless of its <span class="sc">ieee</span> sign bit).
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