python - How do I change the range of the x-axis with datetimes in matplotlib?

Question

I'm trying to plot a graph of dates on the x-axis and values on the y-axis. It works fine, except that I can't get the range of the x-axis to be appropriate. The x-axis range is always Jan 2012 to Jan 2016, despite my dates being from today. I am even specifying that xlim should be the first and last date.

I'm writing this for python-django, if that's relevant.

 import datetime
 import matplotlib.pyplot as plt

 x = [datetime.date(2014, 1, 29), datetime.date(2014, 1, 29), datetime.date(2014, 1, 29)] 
 y = [2, 4, 1]

 fig, ax = plt.subplots()
 ax.plot_date(x, y)
 ax.set_xlim([x[0], x[-1]])

 canvas = FigureCanvas(plt.figure(1))
 response = HttpResponse(content_type='image/png')
 canvas.print_png(response)
 return response

And here is the output:

question from:https://stackoverflow.com/questions/21423158/how-do-i-change-the-range-of-the-x-axis-with-datetimes-in-matplotlib

Answer 1

Edit:

Having seen actual data from the OP, all of the values are at the same date/time. So matplotlib is automatically zooming the x-axis out. You can still manually set the x-axis limits with datetime objects

---

If I do something like this on matplotlib v1.3.1:

import datetime
import matplotlib.pyplot as plt

x = [datetime.date(2014, 1, 29)] * 3 
y = [2, 4, 1]

fig, ax = plt.subplots()
ax.plot_date(x, y, markerfacecolor='CornflowerBlue', markeredgecolor='white')
fig.autofmt_xdate()
ax.set_xlim([datetime.date(2014, 1, 26), datetime.date(2014, 2, 1)])
ax.set_ylim([0, 5])

I get:

And the axes limits match the dates that I specified.