title: Find index positions where 3D-array meets MULTIPLE conditions
body: <p>I have a 3D-array consisting of several numbers within each band. Is there a function that returns the index positions where the array meets MULTIPLE conditions?</p>
  
  <p>I tried the following:</p>
  
  <pre><code>index_pos = numpy.where(
      array[:,:,0]==10 and array[:,:,1]==15 and array[:,:,2]==30)
  </code></pre>
  
  <p>It returns the error:</p>
  
  <pre><code>ValueError: The truth value of an array with more than one element is ambiguous.
  Use a.any() or a.all()
  </code></pre>