[Matplotlib-users] dates for x-axis

[questions a. <que...@gm...>]

Hi matplotlib list,
I am having trouble applying mdates in matplotlib.
I am not sure how to recognise that x-axis are dates like 20110101,
20110102, 20110103 etc.
Any feedback will be greatly appreciated!
below is the code I have so far:

import numpy as np
import matplotlib.pyplot as plt
from numpy import ma as MA
from mpl_toolkits.basemap import Basemap
import os
import glob
import matplotlib.dates as mdates

MainFolder=r"E:/Rainfall/rainfall-2011/test/"
OutputFolder=r"E:/test_out/"

rmax=[]
monthyear=[]

for (path, dirs, files) in os.walk(MainFolder):
    path=path+'/'
    for fname in files:
        if fname.endswith('.txt'):
            filename=path+fname
            fileName, fileExtension=os.path.splitext(fname)
            test=fileName.strip('r')
            test=str(test)
            monthyear.append(test)
            f=np.genfromtxt(filename, skip_header=6)
            dailymax=f.max()
            rmax.append(dailymax)
print rmax
print monthyear

x=monthyear
y=rmax

fig, ax=plt.subplots(1)

plt.plot(x,y)

fig.autofmt_xdate()
ax.fmt_xdata=mdates.DateFormatter('%Y%m%d')

plt.ylabel("Precipitation")
plt.title("Max daily Precipition Vic")
plt.savefig(OutputFolder+"MaxdailyPrecip.png")
plt.show()