import?numpy?as?np
import?matplotlib.pyplot?as?plt
from?sklearn.tree?import?DecisionTreeClassifier
from?ipywidgets?import?interact


def?visualize_tree（estimator?X?y?boundaries=True
???????????????????xlim=None?ylim=None?ax=None）:
????ax?=?ax?or?plt.gca（）
????
????#?Plot?the?training?points
????ax.scatter（X[:?0]?X[:?1]?c=y?s=30?cmap=‘viridis‘
???????????????clim=（y.min（）?y.max（））?zorder=3）
????ax.axis（‘tight‘）
????ax.axis（‘off‘）
????if?xlim?is?None:
????????xlim?=?ax.get_xlim（）
????if?ylim?is?None:
????????ylim?=?ax.get_ylim（）
????
????#?fit?the?estimator
????estimator.fit（X?y）
????xx?yy?=?np.meshgrid（np.linspace（*xlim?num=200）
?????????????????????????np.linspace（*ylim?num=200））
????Z?=?estimator.predict（np.c_[xx.ravel（）?yy.ravel（）]）

????#?Put?the?result?into?a?color?plot
????n_classes?=?len（np.unique（y））
????Z?=?Z.reshape（xx.shape）
????contours?=?ax.contourf（xx?yy?Z?alpha=0.3
???????????????????????????levels=np.arange（n_classes?+?1）?-?0.5
???????????????????????????cmap=‘viridis‘?clim=（y.min（）?y.max（））
???????????????????????????zorder=1）

????ax.set（xlim=xlim?ylim=ylim）
????
????#?Plot?the?decision?boundaries
????def?plot_boundaries（i?xlim?ylim）:
????????if?i?>=?0:
????????????tree?=?estimator.tree_
????????
????????????if?tree.feature[i]?==?0:
????????????????ax.plot（[tree.threshold[i]?tree.threshold[i]]?ylim?‘-k‘?zorder=2）
????????????????plot_boundaries（tree.children_left[i]
????????????????????????????????[xlim[0]?tree.threshold[i]]?ylim）
????????????????plot_boundaries（tree.children_right[i]
????????????????????????????????[tree.threshold[i]?xlim[1]]?ylim）
????????
????????????elif?tree.feature[i]?==?1:
????????????????ax.plot（xlim?[tree.threshold[i]?tree.threshold[i]]?‘-k‘?zorder=2）
????????????????plot_boundaries（tree.children_left[i]?xlim
????????????????????????????????[ylim[0]?tree.threshold[i]]）
????????????????plot_boundaries（tree.children_right[i]?xlim
????????????????????????????????[tree.threshold[i]?ylim[1]]）
????????????
????if?boundaries:
????????plot_boundaries（0?xlim?ylim）


def?plot_tree_interactive（X?y）:
????def?interactive_tree（depth=5）:
????????clf?=?DecisionTreeClassifier（max_depth=depth?random_state=0）
????????visualize_tree（clf?X?y）

????return?interact（interactive_tree?depth=[1?5]）


def?randomized_tree_interactive（X?y）:
????N?=?int（0.75?*?X.shape[0]）
????
????xlim?=?（X[:?0].min（）?X[:?0].max（））
????ylim?=?（X[:?1].min（）?X[:?1].max（））
????
????def?fit_randomized_tree（random_state=0）:
????????clf?=?DecisionTreeClassifier（max_depth=15）
????????i?=?np.arange（len（y））
????????rng?=?np.random.RandomState（random_state）
????????rng.shuffle（i）
????????visualize_tree（clf?X[i[:N]]?y[i[:N]]?boundaries=False
???????????????????????xlim=xlim?ylim=ylim）
????
????interact（fit_randomized_tree?random_state=[0?100]）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2018-08-30?17:23??PythonDataScienceHandbook-master\
?????文件????????1240??2018-08-30?17:23??PythonDataScienceHandbook-master\.gitignore
?????文件?????????259??2018-08-30?17:23??PythonDataScienceHandbook-master\.gitmodules
?????文件????????1083??2018-08-30?17:23??PythonDataScienceHandbook-master\LICENSE-CODE
?????文件???????18650??2018-08-30?17:23??PythonDataScienceHandbook-master\LICENSE-TEXT
?????文件????????3699??2018-08-30?17:23??PythonDataScienceHandbook-master\README.md
?????文件?????????117??2018-08-30?17:23??PythonDataScienceHandbook-master\environment.yml
?????目錄???????????0??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\
?????文件???????13987??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\00.00-Preface.ipynb
?????文件????????8510??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.00-IPython-Beyond-Normal-Python.ipynb
?????文件???????15448??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.01-Help-And-Documentation.ipynb
?????文件???????10620??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.02-Shell-Keyboard-Shortcuts.ipynb
?????文件????????9937??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.03-Magic-Commands.ipynb
?????文件????????9131??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.04-Input-Output-History.ipynb
?????文件???????11580??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.05-IPython-And-Shell-Commands.ipynb
?????文件???????21251??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.06-Errors-and-Debugging.ipynb
?????文件???????18952??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.07-Timing-and-Profiling.ipynb
?????文件????????5629??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\01.08-More-IPython-Resources.ipynb
?????文件????????7586??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.00-Introduction-to-NumPy.ipynb
?????文件???????23921??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.01-Understanding-Data-Types.ipynb
?????文件???????33517??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.02-The-Basics-Of-NumPy-Arrays.ipynb
?????文件???????32076??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.03-Computation-on-arrays-ufuncs.ipynb
?????文件???????31322??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.04-Computation-on-arrays-aggregates.ipynb
?????文件??????102239??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.05-Computation-on-arrays-broadcasting.ipynb
?????文件???????41172??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.06-Boolean-Arrays-and-Masks.ipynb
?????文件???????63008??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.07-Fancy-Indexing.ipynb
?????文件???????62237??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.08-Sorting.ipynb
?????文件???????17253??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\02.09-Structured-Data-NumPy.ipynb
?????文件????????7073??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\03.00-Introduction-to-Pandas.ipynb
?????文件???????40120??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\03.01-Introducing-Pandas-objects.ipynb
?????文件???????41324??2018-08-30?17:23??PythonDataScienceHandbook-master\notebooks\03.02-Data-Indexing-and-Selection.ipynb
............此處省略135個文件信息