matplotlib: Creating two (stacked) subplots with SHARED X axis but SEPARATE Y axis values

Question

I am using matplotlib 1.2.x and Python 2.6.5 on Ubuntu 10.0.4. I am trying to create a SINGLE plot that consists of a top plot and a bottom plot.

The X axis is the date

Answer 1

The example from @Pelson, simplified.

import matplotlib.pyplot as plt
import datetime as dt

#Two subplots that share one x axis
fig,ax=plt.subplots(2,sharex=True)

#plot data
n_pts = 10
dates = [dt.datetime.now() + dt.timedelta(days=i) for i in range(n_pts)]
ax[0].bar(dates, range(10, 20))
ax[1].plot(dates, range(10))

#rotate and format the dates on the x axis
fig.autofmt_xdate()

The subplots sharing an x-axis are created in one line, which is convenient when you want more than two subplots:

fig, ax = plt.subplots(number_of_subplots, sharex=True)

To format the date correctly on the x axis, we can simply use fig.autofmt_xdate()

For additional informations, see shared axis demo and date demo from the pylab examples. This example ran on Python3, matplotlib 1.5.1