启动graphlab create


In [1]:
import graphlab

读取一些房屋销售数据


In [4]:
sales = graphlab.SFrame('home_data.gl/')

In [3]:
sales


Out[3]:
id date price bedrooms bathrooms sqft_living sqft_lot floors waterfront
7129300520 2014-10-13 00:00:00+00:00 221900 3 1 1180 5650 1 0
6414100192 2014-12-09 00:00:00+00:00 538000 3 2.25 2570 7242 2 0
5631500400 2015-02-25 00:00:00+00:00 180000 2 1 770 10000 1 0
2487200875 2014-12-09 00:00:00+00:00 604000 4 3 1960 5000 1 0
1954400510 2015-02-18 00:00:00+00:00 510000 3 2 1680 8080 1 0
7237550310 2014-05-12 00:00:00+00:00 1225000 4 4.5 5420 101930 1 0
1321400060 2014-06-27 00:00:00+00:00 257500 3 2.25 1715 6819 2 0
2008000270 2015-01-15 00:00:00+00:00 291850 3 1.5 1060 9711 1 0
2414600126 2015-04-15 00:00:00+00:00 229500 3 1 1780 7470 1 0
3793500160 2015-03-12 00:00:00+00:00 323000 3 2.5 1890 6560 2 0
view condition grade sqft_above sqft_basement yr_built yr_renovated zipcode lat
0 3 7 1180 0 1955 0 98178 47.51123398
0 3 7 2170 400 1951 1991 98125 47.72102274
0 3 6 770 0 1933 0 98028 47.73792661
0 5 7 1050 910 1965 0 98136 47.52082
0 3 8 1680 0 1987 0 98074 47.61681228
0 3 11 3890 1530 2001 0 98053 47.65611835
0 3 7 1715 0 1995 0 98003 47.30972002
0 3 7 1060 0 1963 0 98198 47.40949984
0 3 7 1050 730 1960 0 98146 47.51229381
0 3 7 1890 0 2003 0 98038 47.36840673
long sqft_living15 sqft_lot15
-122.25677536 1340.0 5650.0
-122.3188624 1690.0 7639.0
-122.23319601 2720.0 8062.0
-122.39318505 1360.0 5000.0
-122.04490059 1800.0 7503.0
-122.00528655 4760.0 101930.0
-122.32704857 2238.0 6819.0
-122.31457273 1650.0 9711.0
-122.33659507 1780.0 8113.0
-122.0308176 2390.0 7570.0
[21613 rows x 21 columns]
Note: Only the head of the SFrame is printed.
You can use print_rows(num_rows=m, num_columns=n) to print more rows and columns.

In [5]:
graphlab.canvas.set_target('ipynb')

In [6]:
sales.show(view='Scatter Plot',x='sqft_living',y='price')


分离出训练集和测试集


In [7]:
train_data,test_data = sales.random_split(.8,seed=0)

构建回归模型


In [8]:
sqft_model = graphlab.linear_regression.create(train_data,target='price',features=['sqft_living'])


PROGRESS: Creating a validation set from 5 percent of training data. This may take a while.
          You can set ``validation_set=None`` to disable validation tracking.

Linear regression:
--------------------------------------------------------
Number of examples          : 16539
Number of features          : 1
Number of unpacked features : 1
Number of coefficients    : 2
Starting Newton Method
--------------------------------------------------------
+-----------+----------+--------------+--------------------+----------------------+---------------+-----------------+
| Iteration | Passes   | Elapsed Time | Training-max_error | Validation-max_error | Training-rmse | Validation-rmse |
+-----------+----------+--------------+--------------------+----------------------+---------------+-----------------+
| 1         | 2        | 1.011163     | 4364275.241291     | 2058699.872718       | 262043.865299 | 280062.713017   |
+-----------+----------+--------------+--------------------+----------------------+---------------+-----------------+
SUCCESS: Optimal solution found.

评估这个简单的线性回归模型


In [21]:
print test_data['price'].mean()

In [22]:
print sqft_model.evaluate(test_data)

看看我们的预测是什么样子的


In [23]:
import sys
reload(sys)
sys.setdefaultencoding('utf8')

In [24]:
import matplotlib.pyplot as plt

In [25]:
%matplotlib inline

In [26]:
plt.plot(test_data['sqft_living'],test_data['price'],'.',
        test_data['sqft_living'],sqft_model.predict(test_data),'-')


Out[26]:
[<matplotlib.lines.Line2D at 0x11e95dfd0>,
 <matplotlib.lines.Line2D at 0x11e96c0d0>]

In [27]:
sqft_model.get('coefficients')


Out[27]:
name index value stderr
(intercept) None -45123.6937457 5030.68958222
sqft_living None 280.568336303 2.21028716034
[2 rows x 4 columns]

探索数据中的其他特征


In [28]:
my_features = ['bedrooms','bathrooms','sqft_living','sqft_lot','floors','zipcode']

In [29]:
sales[my_features].show()



In [30]:
sales.show(view='BoxWhisker Plot',x='zipcode',y='price')


构建更多特征的回归模型

my_features_model = graphlab.linear_regression.create(train_data,target='price',features=my_features)


In [32]:
print my_features

In [33]:
print sqft_model.evaluate(test_data)

In [34]:
print my_features_model.evaluate(test_data)

应用学到的模型来预测房屋的售价


In [35]:
house1 = sales[sales['id']=='5309101200']

In [36]:
house1


Out[36]:
id date price bedrooms bathrooms sqft_living sqft_lot floors waterfront
5309101200 2014-06-05 00:00:00+00:00 620000 4 2.25 2400 5350 1.5 0
view condition grade sqft_above sqft_basement yr_built yr_renovated zipcode lat
0 4 7 1460 940 1929 0 98117 47.67632376
long sqft_living15 sqft_lot15
-122.37010126 1250.0 4880.0
[? rows x 21 columns]
Note: Only the head of the SFrame is printed. This SFrame is lazily evaluated.
You can use sf.materialize() to force materialization.

In [37]:
print house1['price']

In [38]:
print sqft_model.predict(house1)

In [39]:
print my_features_model.predict(house1)

预测另一个房屋的售价


In [40]:
house2 = sales[sales['id']=='1925069082']

In [41]:
house2


Out[41]:
id date price bedrooms bathrooms sqft_living sqft_lot floors waterfront
1925069082 2015-05-11 00:00:00+00:00 2200000 5 4.25 4640 22703 2 1
view condition grade sqft_above sqft_basement yr_built yr_renovated zipcode lat
4 5 8 2860 1780 1952 0 98052 47.63925783
long sqft_living15 sqft_lot15
-122.09722322 3140.0 14200.0
[? rows x 21 columns]
Note: Only the head of the SFrame is printed. This SFrame is lazily evaluated.
You can use sf.materialize() to force materialization.

In [42]:
print sqft_model.predict(house2)

In [43]:
print my_features_model.predict(house2)

In [ ]: