Unexpected value of floor() function in python
<pre><code>import numpy
import math

x = numpy.roots([2,-2,(21 - 21**2)])
print x[0], math.floor(x[0])
</code></pre>

<p>The output is:</p>

<pre><code>15.0 14.0 
</code></pre>

<p>and I expect</p>

<pre><code>15.0 15.0
</code></pre>

<p>I don't expect any reason to have the floor equal to 14.0. Please explain!</p>
