1、学习关联规则挖掘的可视化设计
https://www.cnblogs.com/kori/p/12457472.html
2、用python3编写并运行关联规则的apriori算法。
算法主要代码已经完成,请进行调试,并对给出的菜品数据进行关联规则挖掘。
# -*- coding:utf-8 -*-
import pandas as pd
#from __future__ import print_function
# 导入 apriori 函数
#from apriori import *
# 自定义连接函数,用于实现L_{k-1}到C_k的连接
def connect_string(x, ms):
x = list(map(lambda i: sorted(i.split(ms)), x))
l = len(x[0])
r = []
for i in range(len(x)):
for j in range(i, len(x)):
if x[i][:l - 1] == x[j][:l - 1] and x[i][l - 1] != x[j][l - 1]:
r.append(x[i][:l - 1] + sorted([x[j][l - 1], x[i][l - 1]]))
return r
# 寻找关联规则的函数
def find_rule(d, support, confidence, ms=u'--'):
result = pd.DataFrame(index=['support', 'confidence']) # 定义输出结果
support_series = 1.0 * d.sum() / len(d) # 支持度序列
column = list(support_series[support_series > support].index) # 初步根据支持度筛选
k = 0
while len(column) > 1:
k = k + 1
print(u'\n正在进行#第%d次搜索...' % k)
column = connect_string(column, ms)
print(u'数目:%s...' % len(column))
sf = lambda i: d[i].prod(axis=1, numeric_only=True) # 新一批支持度的计算函数
# 创建连接数据,这一步耗时、耗内存最严重。当数据集较大时,可以考虑并行运算优化。
d_2 = pd.DataFrame(list(map(sf, column)), index=[ms.join(i) for i in column]).T
support_series_2 = 1.0 * d_2[[ms.join(i) for i in column]].sum() / len(d) # 计算连接后的支持度
column = list(support_series_2[support_series_2 > support].index) # 新一轮支持度筛选
support_series = support_series.append(support_series_2)
column2 = []
for i in column: # 遍历可能的推理,如{A,B,C}究竟是A+B-->C还是B+C-->A还是C+A-->B?
i = i.split(ms)
for j in range(len(i)):
column2.append(i[:j] + i[j + 1:] + i[j:j + 1])
cofidence_series = pd.Series(index=[ms.join(i) for i in column2]) # 定义置信度序列
for i in column2: # 计算置信度序列
cofidence_series[ms.join(i)] = support_series[ms.join(sorted(i))] / support_series[ms.join(i[:len(i) - 1])]
for i in cofidence_series[cofidence_series > confidence].index: # 置信度筛选
result[i] = 0.0
result[i]['confidence'] = cofidence_series[i]
result[i]['support'] = support_series[ms.join(sorted(i.split(ms)))]
# result = result.T.sort(['confidence','support'], ascending = False) #结果整理,输出
print(u'\n结果为:')
print(result)
return result
inputfile = 'D:/menu_orders.xls'
outputfile = 'D:/apriori_rules.xls'
data = pd.read_excel(inputfile, header=None)
u"转换原始数据至 0-1 矩阵"
ct = lambda x: pd.Series(1, index=x[pd.notnull(x)]) # 转换成 0-1 矩阵的过渡函数
b = map(ct, data.as_matrix())
data = pd.DataFrame(list(b)).fillna(0) # 实现转换矩阵,空值用 0 填充
data
u"转换完毕"
del b
# 设定最小支持度
support = 0.2
# 设定最小置信度
confidence = 0.5
# 连接符,默认 -- ,需要保证原始表格中不含有该字符
ms = '->'
find_rule(data, support, confidence, ms).to_excel(outputfile)

