<p dir="auto">Qhull apparently has limits on how many input points it can handle. Scipy should check that before trying to use it for too big problems.<br>
<a href="http://mail.scipy.org/pipermail/scipy-dev/2015-June/020820.html" rel="nofollow">http://mail.scipy.org/pipermail/scipy-dev/2015-June/020820.html</a></p>
<p dir="auto">As <a href="https://github.com/scipy/scipy/pull/6768#issuecomment-263086512" data-hovercard-type="pull_request" data-hovercard-url="/scipy/scipy/pull/6768/hovercard">discussed</a> with <a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/rgommers/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/rgommers">@rgommers</a> based on my <code class="notranslate">ConvexHull</code> <a href="https://github.com/scipy/scipy/pull/6768#issuecomment-262762632" data-hovercard-type="pull_request" data-hovercard-url="/scipy/scipy/pull/6768/hovercard">stress tests</a> for the maximum number of input points tolerated, it would perhaps be useful for <code class="notranslate">ConvexHull</code> to capture inputs over the maximum handled size &amp; fail gracefully rather than segfaulting.</p>
<p dir="auto">So, this issue is mostly a reminder / place to discuss possible ways to do this, or if we even need to. The approximate upper limit appears to be around 238 million points (see above links for details).</p>
<p dir="auto">We could also check the quickhull publication for details on space complexity:<br>
Barber, C.B., Dobkin, D.P., and Huhdanpaa, H.T., "The Quickhull algorithm for convex hulls," ACM Trans. on Mathematical Software, 22(4):469-483, Dec 1996</p>
<ul dir="auto">
<li><a href="http://www.cise.ufl.edu/~ungor/courses/fall06/papers/QuickHull.pdf" rel="nofollow">free article PDF</a> -- note that this paper has been cited 3501 times.</li>
</ul>