title: Overlay heatmap on 1D data like ECG signal
body: <p>I have an ECG signal with shape (1, 5000), like this</p>
  <p><a href="https://i.stack.imgur.com/ESXcQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ESXcQ.png" alt="enter image description here" /></a></p>
  <p>and a contribution map with shape (1, 5000), which has values ranging between 0,1.</p>
  <p>I want to plot this contribution map as a heatmap on the ECG signal. Currently, I use <code>plt.pcolormesh(contribution)</code> and plot like this</p>
  <p><a href="https://i.stack.imgur.com/PQyJp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PQyJp.png" alt="enter image description here" /></a></p>
  <p>But how can I overlay a heatmap more beautifully like this plot?</p>
  <p><a href="https://i.stack.imgur.com/gxAyS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gxAyS.png" alt="enter image description here" /></a></p>