<p dir="auto"><code class="notranslate">&gt;&gt;&gt; special.chndtr(np.inf, 16, 30)</code><br>
(five minutes later) ^C^C^C no reaction<br>
ok, <code class="notranslate">kill -9</code></p>
<p dir="auto">this does not seem to depend on other parameters, same story with <code class="notranslate">&gt;&gt;&gt; special.chndtr(np.inf, 16, 30)</code></p>
<p dir="auto">This is used for non-central chi-square:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;&gt;&gt; stats.ncx2.cdf(np.inf, 8, 0.1)
1.0
&gt;&gt;&gt; stats.ncx2._cdf(np.inf, 8, 0.1)"><pre class="notranslate"><code class="notranslate">&gt;&gt;&gt; stats.ncx2.cdf(np.inf, 8, 0.1)
1.0
&gt;&gt;&gt; stats.ncx2._cdf(np.inf, 8, 0.1)
</code></pre></div>
<p dir="auto">(hangs)</p>
<p dir="auto">and skellam, which only defines <code class="notranslate">_cdf</code>, so <code class="notranslate">sf</code> goes via the generic code path:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;&gt;&gt; stats.skellam.cdf(np.inf, 10, 11)
1.0
&gt;&gt;&gt; stats.skellam.sf(np.inf, 10, 11)"><pre class="notranslate"><code class="notranslate">&gt;&gt;&gt; stats.skellam.cdf(np.inf, 10, 11)
1.0
&gt;&gt;&gt; stats.skellam.sf(np.inf, 10, 11)
</code></pre></div>
<p dir="auto">(hangs)</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;python -c &quot;import numpy as np; from scipy import stats; stats.nct._sf(np.nan, 125.531223551, 2.82324307702)&quot;"><pre class="notranslate"><code class="notranslate">&gt;python -c "import numpy as np; from scipy import stats; stats.nct._sf(np.nan, 125.531223551, 2.82324307702)"
</code></pre></div>
<p dir="auto">never comes back</p>
<p dir="auto">I was tracking an rootfinding that never came back that had bad starting values.</p>
<p dir="auto">scipy 0.9.0 and scipy 0.11.0</p>