运用FP-Growth算法对购物篮数据1 2 2 3 4 1 3 4 5 1 4 5 1 2 3 1 2 3 4 1 1 2 3 1 2 4 2 3 5 1 2 3 4 5建立FP树,给出Matlab
时间: 2023-12-02 16:04:10 浏览: 129
数据挖掘 fp-growth的fp树
5星 · 资源好评率100%
以下是使用Matlab实现FP-Growth算法的示例代码,可以对给定的购物篮数据建立FP树:
```matlab
% 定义购物篮数据
data = [1,2; 2,3,4; 1,3,4,5; 1,4,5; 1,2,3; 1,2,3,4; 1; 1,2,3; 1,2,4; 2,3,5; 1,2,3,4,5];
% 定义最小支持度阈值
min_support = 3;
% 计算所有项的支持度
items = unique(data(:));
support = zeros(size(items));
for i = 1:length(items)
support(i) = sum(sum(data == items(i)));
end
% 筛选出频繁项集
freq_items = items(support >= min_support);
% 构建项头表
head_table = cell(length(freq_items), 2);
for i = 1:length(freq_items)
head_table{i, 1} = freq_items(i);
head_table{i, 2} = struct('count', 0, 'node', []);
end
% 构建FP树
root = struct('item', [], 'count', 0, 'children', []);
for i = 1:size(data, 1)
row = data(i, :);
row = row(ismember(row, freq_items)); % 筛选出频繁项
row = sort(row, 'descend'); % 按支持度降序排序
node = root;
for j = 1:length(row)
item = row(j);
child = find_child(node, item);
if isempty(child)
child = struct('item', item, 'count', 0, 'children', []);
node.children = [node.children, child];
% 更新项头表
idx = find(freq_items == item);
head_table{idx, 2}.node = [head_table{idx, 2}.node, child];
end
child.count = child.count + 1;
node = child;
end
end
% 查找节点的子节点
function child = find_child(node, item)
child = [];
for i = 1:length(node.children)
if node.children(i).item == item
child = node.children(i);
break;
end
end
end
```
上述代码实现了对购物篮数据的FP树构建过程,其中使用了项头表来加速查找频繁项的节点。接下来可以使用FP树生成频繁模式,具体实现可以参考FP-Growth算法的原理。
阅读全文