特征工程小案例

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特征工程小案例¶

Kaggle上有这样一个比赛:城市自行车共享系统使用状况。

提供的数据为2年内按小时做的自行车租赁数据,其中训练集由每个月的前19天组成,测试集由20号之后的时间组成。

In [29]:
#先把数据读进来import pandas as pddata = pd.read_csv('kaggle_bike_competition_train.csv', header = 0, error_bad_lines=False)
In [30]:
#看一眼数据长什么样data.head()
Out[30]:
 datetimeseasonholidayworkingdayweathertempatemphumiditywindspeedcasualregisteredcount02011-01-01 00:00:0010019.8414.395810.03131612011-01-01 01:00:0010019.0213.635800.08324022011-01-01 02:00:0010019.0213.635800.05273232011-01-01 03:00:0010019.8414.395750.03101342011-01-01 04:00:0010019.8414.395750.0011

把datetime域切成 日期 和 时间 两部分。

In [32]:
# 处理时间字段temp = pd.DatetimeIndex(data['datetime'])data['date'] = temp.datedata['time'] = temp.timedata.head()
Out[32]:
 datetimeseasonholidayworkingdayweathertempatemphumiditywindspeedcasualregisteredcountdatetime02011-01-01 00:00:0010019.8414.395810.0313162011-01-0100:00:0012011-01-01 01:00:0010019.0213.635800.0832402011-01-0101:00:0022011-01-01 02:00:0010019.0213.635800.0527322011-01-0102:00:0032011-01-01 03:00:0010019.8414.395750.0310132011-01-0103:00:0042011-01-01 04:00:0010019.8414.395750.00112011-01-0104:00:00

时间那部分,好像最细的粒度是小时,所以我们干脆把小时字段拿出来作为更简洁的特征。

In [33]:
# 设定hour这个小时字段data['hour'] = pd.to_datetime(data.time, format="%H:%M:%S")data['hour'] = pd.Index(data['hour']).hourdata
Out[33]:
 datetimeseasonholidayworkingdayweathertempatemphumiditywindspeedcasualregisteredcountdatetimehour02011-01-01 00:00:0010019.8414.395810.0000313162011-01-0100:00:00012011-01-01 01:00:0010019.0213.635800.0000832402011-01-0101:00:00122011-01-01 02:00:0010019.0213.635800.0000527322011-01-0102:00:00232011-01-01 03:00:0010019.8414.395750.0000310132011-01-0103:00:00342011-01-01 04:00:0010019.8414.395750.00000112011-01-0104:00:00452011-01-01 05:00:0010029.8412.880756.00320112011-01-0105:00:00562011-01-01 06:00:0010019.0213.635800.00002022011-01-0106:00:00672011-01-01 07:00:0010018.2012.880860.00001232011-01-0107:00:00782011-01-01 08:00:0010019.8414.395750.00001782011-01-0108:00:00892011-01-01 09:00:00100113.1217.425760.000086142011-01-0109:00:009102011-01-01 10:00:00100115.5819.6957616.99791224362011-01-0110:00:0010112011-01-01 11:00:00100114.7616.6658119.00122630562011-01-0111:00:0011122011-01-01 12:00:00100117.2221.2107719.00122955842011-01-0112:00:0012132011-01-01 13:00:00100218.8622.7257219.99954747942011-01-0113:00:0013142011-01-01 14:00:00100218.8622.7257219.001235711062011-01-0114:00:0014152011-01-01 15:00:00100218.0421.9707719.999540701102011-01-0115:00:0015162011-01-01 16:00:00100217.2221.2108219.99954152932011-01-0116:00:0016172011-01-01 17:00:00100218.0421.9708219.00121552672011-01-0117:00:0017182011-01-01 18:00:00100317.2221.2108816.9979926352011-01-0118:00:0018192011-01-01 19:00:00100317.2221.2108816.9979631372011-01-0119:00:0019202011-01-01 20:00:00100216.4020.4558716.99791125362011-01-0120:00:0020212011-01-01 21:00:00100216.4020.4558712.9980331342011-01-0121:00:0021222011-01-01 22:00:00100216.4020.4559415.00131117282011-01-0122:00:0022232011-01-01 23:00:00100218.8622.7258819.99951524392011-01-0123:00:0023242011-01-02 00:00:00100218.8622.7258819.9995413172011-01-0200:00:000252011-01-02 01:00:00100218.0421.9709416.9979116172011-01-0201:00:001262011-01-02 02:00:00100217.2221.21010019.00121892011-01-0202:00:002272011-01-02 03:00:00100218.8622.7259412.99802462011-01-0203:00:003282011-01-02 04:00:00100218.8622.7259412.99802132011-01-0204:00:004292011-01-02 06:00:00100317.2221.2107719.99950222011-01-0206:00:006................................................108562012-12-18 18:00:00401115.5819.6954622.0028135125252012-12-1818:00:0018108572012-12-18 19:00:00401115.5819.6954626.0027193343532012-12-1819:00:0019108582012-12-18 20:00:00401114.7616.6655016.997942642682012-12-1820:00:0020108592012-12-18 21:00:00401114.7617.4255015.001391591682012-12-1821:00:0021108602012-12-18 22:00:00401113.9416.665490.000051271322012-12-1822:00:0022108612012-12-18 23:00:00401113.9417.425496.0032180812012-12-1823:00:0023108622012-12-19 00:00:00401112.3015.910610.0000635412012-12-1900:00:000108632012-12-19 01:00:00401112.3015.910656.0032114152012-12-1901:00:001108642012-12-19 02:00:00401111.4815.150656.00321232012-12-1902:00:002108652012-12-19 03:00:00401110.6613.635758.99810552012-12-1903:00:003108662012-12-19 04:00:0040119.8412.120758.99811672012-12-1904:00:004108672012-12-19 05:00:00401110.6614.395756.0032229312012-12-1905:00:005108682012-12-19 06:00:0040119.8412.880756.003231091122012-12-1906:00:006108692012-12-19 07:00:00401110.6613.635758.998133603632012-12-1907:00:007108702012-12-19 08:00:0040119.8412.880877.0015136656782012-12-1908:00:008108712012-12-19 09:00:00401111.4814.395757.001583093172012-12-1909:00:009108722012-12-19 10:00:00401113.1216.665707.0015171471642012-12-1910:00:0010108732012-12-19 11:00:00401116.4020.4555415.0013311692002012-12-1911:00:0011108742012-12-19 12:00:00401116.4020.4555419.0012332032362012-12-1912:00:0012108752012-12-19 13:00:00401117.2221.2105012.9980301832132012-12-1913:00:0013108762012-12-19 14:00:00401117.2221.2105012.9980331852182012-12-1914:00:0014108772012-12-19 15:00:00401117.2221.2105019.0012282092372012-12-1915:00:0015108782012-12-19 16:00:00401117.2221.2105023.9994372973342012-12-1916:00:0016108792012-12-19 17:00:00401116.4020.4555026.0027265365622012-12-1917:00:0017108802012-12-19 18:00:00401115.5819.6955023.9994235465692012-12-1918:00:0018108812012-12-19 19:00:00401115.5819.6955026.002773293362012-12-1919:00:0019108822012-12-19 20:00:00401114.7617.4255715.0013102312412012-12-1920:00:0020108832012-12-19 21:00:00401113.9415.9106115.001341641682012-12-1921:00:0021108842012-12-19 22:00:00401113.9417.425616.0032121171292012-12-1922:00:0022108852012-12-19 23:00:00401113.1216.665668.9981484882012-12-1923:00:0023

10886 rows × 15 columns

仔细想想,数据只告诉我们是哪天了,按照一般逻辑,应该周末和工作日出去的人数量不同吧。我们设定一个新的字段dayofweek表示是一周中的第几天。再设定一个字段dateDays表示离第一天开始租车多久了(猜测在欧美国家,这种绿色环保的出行方式,会迅速蔓延吧)

In [35]:
# 我们对时间类的特征做处理,产出一个星期几的类别型变量data['dayofweek'] = pd.DatetimeIndex(data.date).dayofweek# 对时间类特征处理,产出一个时间长度变量data['dateDays'] = (data.date - data.date[0]).astype('timedelta64[D]')data
Out[35]:
 datetimeseasonholidayworkingdayweathertempatemphumiditywindspeedcasualregisteredcountdatetimehourdayofweekdateDays02011-01-01 00:00:0010019.8414.395810.0000313162011-01-0100:00:00050.012011-01-01 01:00:0010019.0213.635800.0000832402011-01-0101:00:00150.022011-01-01 02:00:0010019.0213.635800.0000527322011-01-0102:00:00250.032011-01-01 03:00:0010019.8414.395750.0000310132011-01-0103:00:00350.042011-01-01 04:00:0010019.8414.395750.00000112011-01-0104:00:00450.052011-01-01 05:00:0010029.8412.880756.00320112011-01-0105:00:00550.062011-01-01 06:00:0010019.0213.635800.00002022011-01-0106:00:00650.072011-01-01 07:00:0010018.2012.880860.00001232011-01-0107:00:00750.082011-01-01 08:00:0010019.8414.395750.00001782011-01-0108:00:00850.092011-01-01 09:00:00100113.1217.425760.000086142011-01-0109:00:00950.0102011-01-01 10:00:00100115.5819.6957616.99791224362011-01-0110:00:001050.0112011-01-01 11:00:00100114.7616.6658119.00122630562011-01-0111:00:001150.0122011-01-01 12:00:00100117.2221.2107719.00122955842011-01-0112:00:001250.0132011-01-01 13:00:00100218.8622.7257219.99954747942011-01-0113:00:001350.0142011-01-01 14:00:00100218.8622.7257219.001235711062011-01-0114:00:001450.0152011-01-01 15:00:00100218.0421.9707719.999540701102011-01-0115:00:001550.0162011-01-01 16:00:00100217.2221.2108219.99954152932011-01-0116:00:001650.0172011-01-01 17:00:00100218.0421.9708219.00121552672011-01-0117:00:001750.0182011-01-01 18:00:00100317.2221.2108816.9979926352011-01-0118:00:001850.0192011-01-01 19:00:00100317.2221.2108816.9979631372011-01-0119:00:001950.0202011-01-01 20:00:00100216.4020.4558716.99791125362011-01-0120:00:002050.0212011-01-01 21:00:00100216.4020.4558712.9980331342011-01-0121:00:002150.0222011-01-01 22:00:00100216.4020.4559415.00131117282011-01-0122:00:002250.0232011-01-01 23:00:00100218.8622.7258819.99951524392011-01-0123:00:002350.0242011-01-02 00:00:00100218.8622.7258819.9995413172011-01-0200:00:00061.0252011-01-02 01:00:00100218.0421.9709416.9979116172011-01-0201:00:00161.0262011-01-02 02:00:00100217.2221.21010019.00121892011-01-0202:00:00261.0272011-01-02 03:00:00100218.8622.7259412.99802462011-01-0203:00:00361.0282011-01-02 04:00:00100218.8622.7259412.99802132011-01-0204:00:00461.0292011-01-02 06:00:00100317.2221.2107719.99950222011-01-0206:00:00661.0......................................................108562012-12-18 18:00:00401115.5819.6954622.0028135125252012-12-1818:00:00181717.0108572012-12-18 19:00:00401115.5819.6954626.0027193343532012-12-1819:00:00191717.0108582012-12-18 20:00:00401114.7616.6655016.997942642682012-12-1820:00:00201717.0108592012-12-18 21:00:00401114.7617.4255015.001391591682012-12-1821:00:00211717.0108602012-12-18 22:00:00401113.9416.665490.000051271322012-12-1822:00:00221717.0108612012-12-18 23:00:00401113.9417.425496.0032180812012-12-1823:00:00231717.0108622012-12-19 00:00:00401112.3015.910610.0000635412012-12-1900:00:0002718.0108632012-12-19 01:00:00401112.3015.910656.0032114152012-12-1901:00:0012718.0108642012-12-19 02:00:00401111.4815.150656.00321232012-12-1902:00:0022718.0108652012-12-19 03:00:00401110.6613.635758.99810552012-12-1903:00:0032718.0108662012-12-19 04:00:0040119.8412.120758.99811672012-12-1904:00:0042718.0108672012-12-19 05:00:00401110.6614.395756.0032229312012-12-1905:00:0052718.0108682012-12-19 06:00:0040119.8412.880756.003231091122012-12-1906:00:0062718.0108692012-12-19 07:00:00401110.6613.635758.998133603632012-12-1907:00:0072718.0108702012-12-19 08:00:0040119.8412.880877.0015136656782012-12-1908:00:0082718.0108712012-12-19 09:00:00401111.4814.395757.001583093172012-12-1909:00:0092718.0108722012-12-19 10:00:00401113.1216.665707.0015171471642012-12-1910:00:00102718.0108732012-12-19 11:00:00401116.4020.4555415.0013311692002012-12-1911:00:00112718.0108742012-12-19 12:00:00401116.4020.4555419.0012332032362012-12-1912:00:00122718.0108752012-12-19 13:00:00401117.2221.2105012.9980301832132012-12-1913:00:00132718.0108762012-12-19 14:00:00401117.2221.2105012.9980331852182012-12-1914:00:00142718.0108772012-12-19 15:00:00401117.2221.2105019.0012282092372012-12-1915:00:00152718.0108782012-12-19 16:00:00401117.2221.2105023.9994372973342012-12-1916:00:00162718.0108792012-12-19 17:00:00401116.4020.4555026.0027265365622012-12-1917:00:00172718.0108802012-12-19 18:00:00401115.5819.6955023.9994235465692012-12-1918:00:00182718.0108812012-12-19 19:00:00401115.5819.6955026.002773293362012-12-1919:00:00192718.0108822012-12-19 20:00:00401114.7617.4255715.0013102312412012-12-1920:00:00202718.0108832012-12-19 21:00:00401113.9415.9106115.001341641682012-12-1921:00:00212718.0108842012-12-19 22:00:00401113.9417.425616.0032121171292012-12-1922:00:00222718.0108852012-12-19 23:00:00401113.1216.665668.9981484882012-12-1923:00:00232718.0

10886 rows × 17 columns

其实我们刚才一直都在猜测,并不知道真实的日期相关的数据分布对吧,所以我们要做一个小小的统计来看看真实的数据分布,我们统计一下一周各天的自行车租赁情况(分注册的人和没注册的人)

In [36]:
byday = data.groupby('dayofweek')# 统计下没注册的用户租赁情况byday['casual'].sum().reset_index()
Out[36]:
 dayofweekcasual00462881135365223493133372834447402551007826690084
In [37]:
# 统计下注册的用户的租赁情况byday['registered'].sum().reset_index()
Out[37]:
 dayofweekregistered00249008112566202225729533269118442551025521073666195462

周末既然有不同,就单独拿一列出来给星期六,再单独拿一列出来给星期日

In [38]:
data['Saturday']=0data.Saturday[data.dayofweek==5]=1data['Sunday']=0data.Sunday[data.dayofweek==6]=1data
/opt/conda/envs/python2/lib/python2.7/site-packages/ipykernel/__main__.py:2: SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrameSee the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy  from ipykernel import kernelapp as app/opt/conda/envs/python2/lib/python2.7/site-packages/ipykernel/__main__.py:5: SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrameSee the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
Out[38]:
 datetimeseasonholidayworkingdayweathertempatemphumiditywindspeedcasualregisteredcountdatetimehourdayofweekdateDaysSaturdaySunday02011-01-01 00:00:0010019.8414.395810.0000313162011-01-0100:00:00050.01012011-01-01 01:00:0010019.0213.635800.0000832402011-01-0101:00:00150.01022011-01-01 02:00:0010019.0213.635800.0000527322011-01-0102:00:00250.01032011-01-01 03:00:0010019.8414.395750.0000310132011-01-0103:00:00350.01042011-01-01 04:00:0010019.8414.395750.00000112011-01-0104:00:00450.01052011-01-01 05:00:0010029.8412.880756.00320112011-01-0105:00:00550.01062011-01-01 06:00:0010019.0213.635800.00002022011-01-0106:00:00650.01072011-01-01 07:00:0010018.2012.880860.00001232011-01-0107:00:00750.01082011-01-01 08:00:0010019.8414.395750.00001782011-01-0108:00:00850.01092011-01-01 09:00:00100113.1217.425760.000086142011-01-0109:00:00950.010102011-01-01 10:00:00100115.5819.6957616.99791224362011-01-0110:00:001050.010112011-01-01 11:00:00100114.7616.6658119.00122630562011-01-0111:00:001150.010122011-01-01 12:00:00100117.2221.2107719.00122955842011-01-0112:00:001250.010132011-01-01 13:00:00100218.8622.7257219.99954747942011-01-0113:00:001350.010142011-01-01 14:00:00100218.8622.7257219.001235711062011-01-0114:00:001450.010152011-01-01 15:00:00100218.0421.9707719.999540701102011-01-0115:00:001550.010162011-01-01 16:00:00100217.2221.2108219.99954152932011-01-0116:00:001650.010172011-01-01 17:00:00100218.0421.9708219.00121552672011-01-0117:00:001750.010182011-01-01 18:00:00100317.2221.2108816.9979926352011-01-0118:00:001850.010192011-01-01 19:00:00100317.2221.2108816.9979631372011-01-0119:00:001950.010202011-01-01 20:00:00100216.4020.4558716.99791125362011-01-0120:00:002050.010212011-01-01 21:00:00100216.4020.4558712.9980331342011-01-0121:00:002150.010222011-01-01 22:00:00100216.4020.4559415.00131117282011-01-0122:00:002250.010232011-01-01 23:00:00100218.8622.7258819.99951524392011-01-0123:00:002350.010242011-01-02 00:00:00100218.8622.7258819.9995413172011-01-0200:00:00061.001252011-01-02 01:00:00100218.0421.9709416.9979116172011-01-0201:00:00161.001262011-01-02 02:00:00100217.2221.21010019.00121892011-01-0202:00:00261.001272011-01-02 03:00:00100218.8622.7259412.99802462011-01-0203:00:00361.001282011-01-02 04:00:00100218.8622.7259412.99802132011-01-0204:00:00461.001292011-01-02 06:00:00100317.2221.2107719.99950222011-01-0206:00:00661.001............................................................108562012-12-18 18:00:00401115.5819.6954622.0028135125252012-12-1818:00:00181717.000108572012-12-18 19:00:00401115.5819.6954626.0027193343532012-12-1819:00:00191717.000108582012-12-18 20:00:00401114.7616.6655016.997942642682012-12-1820:00:00201717.000108592012-12-18 21:00:00401114.7617.4255015.001391591682012-12-1821:00:00211717.000108602012-12-18 22:00:00401113.9416.665490.000051271322012-12-1822:00:00221717.000108612012-12-18 23:00:00401113.9417.425496.0032180812012-12-1823:00:00231717.000108622012-12-19 00:00:00401112.3015.910610.0000635412012-12-1900:00:0002718.000108632012-12-19 01:00:00401112.3015.910656.0032114152012-12-1901:00:0012718.000108642012-12-19 02:00:00401111.4815.150656.00321232012-12-1902:00:0022718.000108652012-12-19 03:00:00401110.6613.635758.99810552012-12-1903:00:0032718.000108662012-12-19 04:00:0040119.8412.120758.99811672012-12-1904:00:0042718.000108672012-12-19 05:00:00401110.6614.395756.0032229312012-12-1905:00:0052718.000108682012-12-19 06:00:0040119.8412.880756.003231091122012-12-1906:00:0062718.000108692012-12-19 07:00:00401110.6613.635758.998133603632012-12-1907:00:0072718.000108702012-12-19 08:00:0040119.8412.880877.0015136656782012-12-1908:00:0082718.000108712012-12-19 09:00:00401111.4814.395757.001583093172012-12-1909:00:0092718.000108722012-12-19 10:00:00401113.1216.665707.0015171471642012-12-1910:00:00102718.000108732012-12-19 11:00:00401116.4020.4555415.0013311692002012-12-1911:00:00112718.000108742012-12-19 12:00:00401116.4020.4555419.0012332032362012-12-1912:00:00122718.000108752012-12-19 13:00:00401117.2221.2105012.9980301832132012-12-1913:00:00132718.000108762012-12-19 14:00:00401117.2221.2105012.9980331852182012-12-1914:00:00142718.000108772012-12-19 15:00:00401117.2221.2105019.0012282092372012-12-1915:00:00152718.000108782012-12-19 16:00:00401117.2221.2105023.9994372973342012-12-1916:00:00162718.000108792012-12-19 17:00:00401116.4020.4555026.0027265365622012-12-1917:00:00172718.000108802012-12-19 18:00:00401115.5819.6955023.9994235465692012-12-1918:00:00182718.000108812012-12-19 19:00:00401115.5819.6955026.002773293362012-12-1919:00:00192718.000108822012-12-19 20:00:00401114.7617.4255715.0013102312412012-12-1920:00:00202718.000108832012-12-19 21:00:00401113.9415.9106115.001341641682012-12-1921:00:00212718.000108842012-12-19 22:00:00401113.9417.425616.0032121171292012-12-1922:00:00222718.000108852012-12-19 23:00:00401113.1216.665668.9981484882012-12-1923:00:00232718.000

10886 rows × 19 columns

从数据中,把原始的时间字段等踢掉

In [39]:
# remove old data featuresdataRel = data.drop(['datetime', 'count','date','time','dayofweek'], axis=1)dataRel.head()
Out[39]:
 seasonholidayworkingdayweathertempatemphumiditywindspeedcasualregisteredhourdateDaysSaturdaySunday010019.8414.395810.031300.010110019.0213.635800.083210.010210019.0213.635800.052720.010310019.8414.395750.031030.010410019.8414.395750.00140.010

特征向量化

我们这里打算用scikit-learn来建模。对于pandas的dataframe我们有方法/函数可以直接转成python中的dict。 另外,在这里我们要对离散值和连续值特征区分一下了,以便之后分开做不同的特征处理。

In [40]:
from sklearn.feature_extraction import DictVectorizer# 我们把连续值的属性放入一个dict中featureConCols = ['temp','atemp','humidity','windspeed','dateDays','hour']dataFeatureCon = dataRel[featureConCols]dataFeatureCon = dataFeatureCon.fillna( 'NA' ) #in case I missed anyX_dictCon = dataFeatureCon.T.to_dict().values() # 把离散值的属性放到另外一个dict中featureCatCols = ['season','holiday','workingday','weather','Saturday', 'Sunday']dataFeatureCat = dataRel[featureCatCols]dataFeatureCat = dataFeatureCat.fillna( 'NA' ) #in case I missed anyX_dictCat = dataFeatureCat.T.to_dict().values() # 向量化特征vec = DictVectorizer(sparse = False)X_vec_cat = vec.fit_transform(X_dictCat)X_vec_con = vec.fit_transform(X_dictCon)
In [41]:
dataFeatureCon.head()
Out[41]:
 tempatemphumiditywindspeeddateDayshour09.8414.395810.00.0019.0213.635800.00.0129.0213.635800.00.0239.8414.395750.00.0349.8414.395750.00.04
In [42]:
X_vec_con
Out[42]:
array([[  14.395 ,    0.    ,    0.    ,   81.    ,    9.84  ,    0.    ],       [  13.635 ,    0.    ,    1.    ,   80.    ,    9.02  ,    0.    ],       [  13.635 ,    0.    ,    2.    ,   80.    ,    9.02  ,    0.    ],       ...,        [  15.91  ,  718.    ,   21.    ,   61.    ,   13.94  ,   15.0013],       [  17.425 ,  718.    ,   22.    ,   61.    ,   13.94  ,    6.0032],       [  16.665 ,  718.    ,   23.    ,   66.    ,   13.12  ,    8.9981]])
In [43]:
dataFeatureCat.head()
Out[43]:
 seasonholidayworkingdayweatherSaturdaySunday01001101100110210011031001104100110
In [44]:
X_vec_cat
Out[44]:
array([[ 1.,  0.,  0.,  1.,  1.,  0.],       [ 1.,  0.,  0.,  1.,  1.,  0.],       [ 1.,  0.,  0.,  1.,  1.,  0.],       ...,        [ 0.,  0.,  0.,  4.,  1.,  1.],       [ 0.,  0.,  0.,  4.,  1.,  1.],       [ 0.,  0.,  0.,  4.,  1.,  1.]])

标准化连续值特征

我们要对连续值属性做一些处理,最基本的当然是标准化,让连续值属性处理过后均值为0,方差为1。 这样的数据放到模型里,对模型训练的收敛和模型的准确性都有好处

In [18]:
from sklearn import preprocessing# 标准化连续值数据scaler = preprocessing.StandardScaler().fit(X_vec_con)X_vec_con = scaler.transform(X_vec_con)X_vec_con
Out[18]:
array([[-1.09273697, -1.70912256, -1.66894356,  0.99321305, -1.33366069,        -1.56775367],       [-1.18242083, -1.70912256, -1.52434128,  0.94124921, -1.43890721,        -1.56775367],       [-1.18242083, -1.70912256, -1.379739  ,  0.94124921, -1.43890721,        -1.56775367],       ...,        [-0.91395927,  1.70183906,  1.36770431, -0.04606385, -0.80742813,         0.26970368],       [-0.73518157,  1.70183906,  1.51230659, -0.04606385, -0.80742813,        -0.83244247],       [-0.82486544,  1.70183906,  1.65690887,  0.21375537, -0.91267464,        -0.46560752]])

类别特征编码

最常用的当然是one-hot编码咯,比如颜色 红、蓝、黄 会被编码为[1, 0, 0],[0, 1, 0],[0, 0, 1]

In [20]:
from sklearn import preprocessing# one-hot编码enc = preprocessing.OneHotEncoder()enc.fit(X_vec_cat)X_vec_cat = enc.transform(X_vec_cat).toarray()X_vec_cat
Out[20]:
array([[ 1.,  0.,  0., ...,  1.,  1.,  0.],       [ 1.,  0.,  0., ...,  1.,  1.,  0.],       [ 1.,  0.,  0., ...,  1.,  1.,  0.],       ...,        [ 0.,  1.,  1., ...,  0.,  0.,  1.],       [ 0.,  1.,  1., ...,  0.,  0.,  1.],       [ 0.,  1.,  1., ...,  0.,  0.,  1.]])

把特征拼一起

把离散和连续的特征都组合在一起

In [22]:
import numpy as np# combine cat & con featuresX_vec = np.concatenate((X_vec_con,X_vec_cat), axis=1)X_vec
Out[22]:
array([[-1.09273697, -1.70912256, -1.66894356, ...,  1.        ,         1.        ,  0.        ],       [-1.18242083, -1.70912256, -1.52434128, ...,  1.        ,         1.        ,  0.        ],       [-1.18242083, -1.70912256, -1.379739  , ...,  1.        ,         1.        ,  0.        ],       ...,        [-0.91395927,  1.70183906,  1.36770431, ...,  0.        ,         0.        ,  1.        ],       [-0.73518157,  1.70183906,  1.51230659, ...,  0.        ,         0.        ,  1.        ],       [-0.82486544,  1.70183906,  1.65690887, ...,  0.        ,         0.        ,  1.        ]])

最后的特征,前6列是标准化过后的连续值特征,后面是编码后的离散值特征

对结果值也处理一下

拿到结果的浮点数值

In [23]:
# 对Y向量化Y_vec_reg = dataRel['registered'].values.astype(float)Y_vec_cas = dataRel['casual'].values.astype(float)
In [24]:
# 看看处理后的结果值Y_vec_reg
Out[24]:
array([  13.,   32.,   27., ...,  164.,  117.,   84.])
In [25]:
Y_vec_cas
Out[25]:
array([  3.,   8.,   5., ...,   4.,  12.,   4.])
0 0
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