robability estimates (defaults to
 <a href="../../../../../org/apache/commons/math3/distribution/GammaDistribution.html#DEFAULT_INVERSE_ABSOLUTE_ACCURACY"><code>DEFAULT_INVERSE_ABSOLUTE_ACCURACY</code></a>).</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../../../org/apache/commons/math3/exception/NotStrictlyPositiveException.html" title="class in org.apache.commons.math3.exception">NotStrictlyPositiveException</a></code> - if <code>shape &lt;= 0</code> or
 <code>scale &lt;= 0</c