IncationException：未找到 GraphViz 的可执行文件

Question

我无法可视化或编写决策树。我该怎么办呢？

Python版本3.5，Anaconda 3，我什至设置了环境变量

    from sklearn import tree
    model = tree.DecisionTreeClassifier(criterion='gini') 
    model=tree.DecisionTreeClassifier()
    model.fit(trainData,trainLabel)
    model.score(trainData,trainLabel)
    predicted= model.predict(testData)

    from sklearn.externals.six import StringIO
    import pydot 
    import pydotplus
    dot_data = StringIO() 
    tree.export_graphviz(model, out_file=dot_data) 
    graph = pydotplus.graph_from_dot_data(dot_data.getvalue()) 
    print(graph)
    graph.write_pdf("C:\\Users\\anagha\\Desktop\\SynehackData\\DATA\\DATA\\graph.pdf") 

错误 ：

InvocationException: GraphViz's executables not found

Answer 1

您可以利用此代码获得帮助！

import pydotplus
from sklearn.datasets import load_iris
from sklearn import tree
import collections

# Data Collection
X = [ [180, 15,0],     
      [177, 42,0],
      [136, 35,1],
      [174, 65,0],
      [141, 28,1]]

Y = ['man', 'woman', 'woman', 'man', 'woman']    

data_feature_names = [ 'height', 'hair length', 'voice pitch' ]

# Training
clf = tree.DecisionTreeClassifier()
clf = clf.fit(X,Y)
# Visualize data
dot_data = tree.export_graphviz(clf,
                                feature_names=data_feature_names,
                                out_file=None,
                                filled=True,
                                rounded=True)
graph = pydotplus.graph_from_dot_data(dot_data)

colors = ('turquoise', 'orange')
edges = collections.defaultdict(list)

for edge in graph.get_edge_list():
    edges[edge.get_source()].append(int(edge.get_destination()))

for edge in edges:
    edges[edge].sort()    
    for i in range(2):
        dest = graph.get_node(str(edges[edge][i]))[0]
        dest.set_fillcolor(colors[i])

graph.write_png('tree.png')