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<html><head>
<title>cl:round</title>
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<a href="../../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../../manual/contents.htm">Contents</a> |
<a href="../../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples.htm">Examples</a> |
<a href="../../reference/reference-index.htm">Reference</a>
<hr>
<h1>cl:round</h1>
<hr>
<p>The <nobr>cl:<b>round</b></nobr> function
<a href="../../reference/truncate.htm">truncate</a>s an integer or
<nobr>floating-point</nobr> number toward the next integer:</p>
<p><div class="box">
<dl>
<dt>(cl:<b>round</b> <i>number </i> [<i>divisor</i>])</dt>
<dd><i>number</i> - an integer or <nobr>floating-point</nobr> number<br>
<i>divisor</i> - an integer or <nobr>floating-point</nobr> number, except zero<br>
<table cellpadding="0" cellspacing="0"><tbody>
<tr>
<td valign="top"><nobr>returns</nobr></td>
<td valign="top"><nobr> - </nobr></td>
<td width="100%">the result of runding the result of <i>number</i> divided by <i>divisor</i></td>
</tr>
<tr>
<td></td>
<td valign="top"><nobr> - </nobr></td>
<td width="100%">the remainder of the round operation</td>
</tr>
</tbody></table></dd>
</dl>
</div></p>
<pre class="example">
(defun <font color="#0000CC">cl:round</font> (number &optional (divisor
(if (integerp number) 1 1.0)
divisor-p))
(let* ((x (/ (float number) divisor))
(quotient (cond ((and (not divisor-p) (integerp number)) number)
((= number divisor) 1)
((plusp x) (truncate (+ x 0.5)))
((= (- x 0.5) (truncate (- x 0.5)))
(if (minusp x)
(1- (truncate x))
(truncate x)))
(t (truncate (- x 0.5))))))
(setq <font color="#AA5500">*rslt*</font> (list quotient (- number (* quotient divisor)))
<font color="#AA5500">cl:*multiple-values*</font> t)
quotient))
</pre>
<p>The <nobr>cl:<b>round</b></nobr> function computes a quotient that has
been rounded to the nearest mathematical integer. <nobr>If the</nobr>
mathematical quotient is exactly halfway between two integers, [that is, it
has the form <nobr>'integer+1/2']</nobr>, then the quotient has been rounded
to the even [divisible <nobr>by two]</nobr> integer.</p>
<p>The quotient is directly returned by the function, while a list:</p>
<pre class="example">
(quotient remainder)
</pre>
<p>is stored in the Nyquist/XLISP
<a href="../../reference/global-rslt.htm">*rslt*</a> variable and the
<a href="global-multiple-values.htm">cl:*multiple-values*</a> is set to
<a href="../../reference/t.htm"> T </a> to signal that
<a href="multiple-values.htm">Multiple Values</a> are returned.</p>
<nobr>See
<a href="rounding-and-truncation.htm">Rounding and Truncation</a></nobr>
for more details.</p>
<p>Examples:</p>
<pre class="example">
(round 3.5) => 4
(round -3.5) => -3
(cl:round 3.5) => 4 <font color="#008844">; *rslt* = ( 4 -0.5)</font>
(cl:round -3.5) => -4 <font color="#008844">; *rslt* = (-4 0.5)</font>
</pre>
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