title: Check array for values equal or very close to zero
body: <p>I have a one dimensional <code>numpy</code> array for which I need to find out if <em>any value</em> is zero or very close to it.
  With this line I can check for zeros rapidly:</p>
  
  <pre><code>if 0. in my_array:
      # do something
  </code></pre>
  
  <p>but I also have very small elements like 1.e-22 which I would also like to treat as zeros (otherwise I get a <em>Divide by zero</em> warning further down the road)</p>
  
  <p>Say my threshold is 1.e-6 and I want to efficiently check if <em>any</em> value in my array is smaller than that. How can I do this?</p>