(double[]&nbsp;x,
                  double&nbsp;y)
                    throws <a href="../../../../../../org/apache/commons/math3/stat/regression/ModelSpecificationException.html" title="class in org.apache.commons.math3.stat.regression">ModelSpecificationException</a></pre>
<div class="block">Adds one observation to the regression model.</div>
<dl>
<dt><strong>Specified by:</strong></dt>
<dd><code><a href="../../../../../../org/apache/commons/math3/stat/regression/UpdatingMultipleLinearRegression.html#addO