Numpy's dot product not associative
<p>Computing the <code>dot</code> product in the following three cases produce different results for my specific set of complex NumPy arrays, but not for a second set of random matrices which have the same sizes and data ranges.</p>

<pre><code>a.dot(b).dot(c).dot(d)
a.dot(b.dot(c).dot(d))
a.dot(b.dot(c)).dot(d)
</code></pre>

<p>produces</p>

<pre><code>[[  2.23903250e-08 -1.29444679e-07j]]
[[  6.09565057e-07 +2.09702260e-07j]]
[[  3.40257465e-07 -1.20382176e-07j]]
</code></pre>

<p>The arrays are quite large with one having around 14 mio. entries. Could the size be an issue? If so, why does numpy not raise a warining?</p>