docs: def update(self):
          """Updates image to be displayed with new time frame."""
          if self.single_channel:
              self.im.set_data(self.data[self.ind, :, :])
          else:
              self.im.set_data(self.data[self.ind, :, :, :])
          self.ax.set_ylabel('time frame %s' % self.ind)
          self.im.axes.figure.canvas.draw()