Create a twin Axes sharing the xaxis
create a twin of Axes for generating a plot with a sharex
x-axis but independent y axis. The y-axis of self will have
ticks on left and the returned axes will have ticks on the
right. To ensure tick marks of both axis align, see
For those who are ‘picking’ artists while using twinx, pick events are only called for the artists in the top-most axes.