Matplotlib:在3D条形图中格式化x轴上的日期

Question

给定这个3D条形图示例代码,您如何将x轴中的数值数据转换为格式化的日期/时间字符串？我试图使用ax.xaxis_date()函数但没有成功.我也尝试使用plot_date(),它似乎不适用于3D条形图.以下是示例代码的修改版本,用于说明我要执行的操作:

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.dates as dates

dates = [dates.date2num(datetime.datetime(2009,3,12)),
         dates.date2num(datetime.datetime(2009,6,9)),
         dates.date2num(datetime.datetime(2010,1,1)),
         #etc...
         ]

fig = plt.figure()
ax = Axes3D(fig)
for c, z in zip(['r', 'g', 'b', 'y'], [30, 20, 10, 0]):
    xs = np.array(dates)
    ys = np.random.rand(20)
    ax.bar(xs, ys, zs=z, zdir='y', color=c, alpha=0.8)

ax.set_xlabel('Date & Time')
ax.set_ylabel('Series')
ax.set_zlabel('Amount')

plt.show()

alt text http://matplotlib.sourceforge.net/_images/bars3d_demo1.png

Answer 1

这里可能存在一些混淆,Axes3D具有轴的属性w_xaxis,w_yaxis和w_zaxis,而不是通常的xaxix,yaxis等.

UPDATE现在使用函数来格式化标签.

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.dates as dates
import datetime, random
import matplotlib.ticker as ticker

def random_date():
      date = datetime.date(2008, 12,01)
      while 1:
        date += datetime.timedelta(days=30)
        yield (date)

def format_date(x, pos=None):
     return dates.num2date(x).strftime('%Y-%m-%d') #use FuncFormatter to format dates

r_d = random_date()
some_dates = [dates.date2num(r_d.next()) for i in range(0,20)]

fig = plt.figure()
ax = Axes3D(fig,rect=[0,0.1,1,1]) #make room for date labels

for c, z in zip(['r', 'g', 'b', 'y'], [30, 20, 10, 0]):
    xs = np.array(some_dates)
    ys = np.random.rand(20)
    ax.bar(xs, ys, zs=z, zdir='y', color=c, alpha=0.8,width=8)

ax.w_xaxis.set_major_locator(ticker.FixedLocator(some_dates)) # I want all the dates on my xaxis
ax.w_xaxis.set_major_formatter(ticker.FuncFormatter(format_date))
for tl in ax.w_xaxis.get_ticklabels(): # re-create what autofmt_xdate but with w_xaxis
       tl.set_ha('right')
       tl.set_rotation(30)     

ax.set_ylabel('Series')
ax.set_zlabel('Amount')

plt.show()

生产:

alt text http://www.imagechicken.com/uploads/1265570252049424000.png