title: Numpy arrays - matrix multiplying arrays but taking 1 - elements in certain columns in the second array
body: <p>Is it possible to multiply two matrices together, but taking 1-elements in a certain column? I am multiplying large numpy arrays and don't want to break the arrays apart into multiple instances because I am running out of memory.</p>
  <p>For example:</p>
  <pre><code>a=np.array([[0.1, 0.2],[0.3, 0.4]])
  b=np.array([[0.25],[0.4]])
  c = np.matmul(a,b)
  </code></pre>
  <p>except 1-b used multiplication:</p>
  <pre><code>1-b=np.array([[0.75], [0.6]])
  </code></pre>
  <p>before the matrix multiplication, but doesn't save it into memory after the calculation is done</p>