学习pyspark（九）：使用ml.regression模块预测房价

数据下载：

该数据集源自Kaggle平台的波士顿房价预测相关数据，地址为：https://www.kaggle.com/c/boston-housing/data 除此之外，在https://github.com/ffzs/dataset/tree/master/boston处亦可获取

数据准备：

相关参数：

CRIM：townwide average crime rate per capita。
ZN - Proportion of residential land exceeding 25,000 sq.ft.
INDUS - Percentage of non-retail business areas in a town.
CHAS - Charles River dummy variable (1 if tract bounds river; 0 otherwise).
NOX - Nitrogen oxides concentration (parts per million).
RM - Number of rooms per dwelling.
AGE - Proportion of owner-occupied units built before 1940.
DIS - Weighted d