我是pyspark的新手，我正在尝试使用一个名为movielens100k的在线公开样本数据集。我通过命令行使用pyspark。
当我尝试创建直方图时，它不会显示。我收到消息“this plugin does not support propagatesizehints（）”，然后当我再次尝试该命令以显示直方图时，什么也没有发生。没有错误，没有输出或任何东西。这是我的密码：

>>> import numpy
>>> import pandas
>>> import sklearn
>>> import os
>>> os.environ['QT_QPA_PLATFORM']='offscreen'
>>> import matplotlib.pyplot
>>> user_data = sc.textFile("...../ml-100k/u.user")
>>> user_fields = user_data.map(lambda line: line.split("|"))
>>> ages = user_fields.map(lambda x: int(x[1])).collect()
>>> import pylab
>>> pylab.hist(ages, bins=20, color='lightblue', normed=True)

这是此时的输出：

QFontDatabase: Cannot find font directory
 /var/hadoop/anaconda2/lib/fonts - is Qt installed correctly?
 QFontDatabase: Cannot find font directory
 /var/hadoop/anaconda2/lib/fonts - is Qt installed correctly?
 QFontDatabase: Cannot find font directory
 /var/hadoop/anaconda2/lib/fonts - is Qt installed correctly?
 QFontDatabase: Cannot find font directory
 /var/hadoop/anaconda2/lib/fonts - is Qt installed correctly? (array([
 0.00064269,  0.00192808,  0.00449886,  0.0279572 ,  0.02956393,
         0.03374144,  0.04563129,  0.02538642,  0.02088756,  0.01863813,
         0.02088756,  0.01606735,  0.0170314 ,  0.01863813,  0.00674829,
         0.00482021,  0.0054629 ,  0.00192808,  0.00128539,  0.00128539]), array([  7. ,  10.3,  13.6,  16.9,  20.2,  23.5,  26.8,  30.1,  33.4,
         36.7,  40. ,  43.3,  46.6,  49.9,  53.2,  56.5,  59.8,  63.1,
         66.4,  69.7,  73. ]), <a list of 20 Patch objects>)

当我尝试渲染图形时，会发生以下情况：

>>> fig = matplotlib.pyplot.gcf()
>>> fig.set_size_inches(16, 10)
>>> fig.show()
This plugin does not support propagateSizeHints()
>>> fig.show()
>>>

请让我知道如何解决这个问题，使直方图出现。谢谢！