問題描述
在我學(xué)習(xí)機(jī)器學(xué)習(xí)實戰(zhàn)-決策樹部分检诗，欲可視化決策樹結(jié)構(gòu)匈仗。最終可視化結(jié)果：
在這里插入圖片描述
在這里插入圖片描述
解決方案
決策樹由嵌套字典組成，如：
{"no surfacing": {0: "no", 1: {"flippers": {0: "no", 1: "yes"}}}}
{'tearRate': {'reduced': 'no lenses', 'normal': {'astigmatic': {'no': {'age': {'young': 'soft', 'presbyopic': {'prescript': {'myope': 'no lenses', 'hyper': 'soft'}}, 'pre': 'soft'}}, 'yes': {'prescript': {'myope': 'hard', 'hyper': {'age': {'young': 'hard', 'presbyopic': 'no lenses', 'pre': 'no lenses'}}}}}}}}
使用graphviz包中的畫點和連線逢慌。代碼如下：
"""
@author: lishihang
@software: PyCharm
@file: TreeVis.py
@time: 2018/11/29 22:20
"""
from graphviz import Digraph
def plot_model(tree, name):
g = Digraph("G", filename=name, format='png', strict=False)
first_label = list(tree.keys())[0]
g.node("0", first_label)
_sub_plot(g, tree, "0")
g.view()
root = "0"
def _sub_plot(g, tree, inc):
global root
first_label = list(tree.keys())[0]
ts = tree[first_label]
for i in ts.keys():
if isinstance(tree[first_label][i], dict):
root = str(int(root) + 1)
g.node(root, list(tree[first_label][i].keys())[0])
g.edge(inc, root, str(i))
_sub_plot(g, tree[first_label][i], root)
else:
root = str(int(root) + 1)
g.node(root, tree[first_label][i])
g.edge(inc, root, str(i))
d1 = {"no surfacing": {0: "no", 1: {"flippers": {0: "no", 1: "yes"}}}}
d2 = {'tearRate': {'reduced': 'no lenses', 'normal': {'astigmatic': {'yes': {
'prescript': {'myope': 'hard', 'hyper': {'age': {'young': 'hard', 'presbyopic': 'no lenses', 'pre': 'no lenses'}}}},
'no': {'age': {'young': 'soft', 'presbyopic': {
'prescript': {'myope': 'no lenses',
'hyper': 'soft'}},
'pre': 'soft'}}}}}}
plot_model(d1, "hello.gv")
plot_model(d2, "hello2.gv")
