for i in range(len(X)):neighbor_list.append(find_neighbor(i, X, eps)) if len(neighbor_list[-1]) >= min_Pts:omega_list.append(i)
时间: 2024-06-07 22:09:48 浏览: 175
这是一个基于密度的聚类算法中的核心代码,实现了寻找密度可达点的过程。
其中X是数据集,eps是半径阈值,min_Pts是密度阈值。
首先通过for循环遍历数据集中的每一个点,并通过find_neighbor函数找到距离该点在eps范围内的所有邻居点,将邻居点的索引存储在neighbor_list中,然后判断邻居点的数量是否大于等于密度阈值min_Pts。
如果是,则将该点的索引i存储在omega_list中,表示该点是核心点。
如果不是,则该点为边界点或噪声点,不存储在omega_list中。
相关问题
def DBSCAN(X, eps, min_Pts): k = -1 neighbor_list = [] # 用来保存每个数据的邻域 omega_list = [] # 核心对象集合 gama = set([x for x in range(len(X))]) # 初始时将所有点标记为未访问 cluster = [-1 for _ in range(len(X))] # 聚类 for i in range(len(X)): neighbor_list.append(find_neighbor(i, X, eps)) if len(neighbor_list[-1]) >= min_Pts: omega_list.append(i) # 将样本加入核心对象集合 omega_list = set(omega_list) # 转化为集合便于操作 while len(omega_list) > 0: gama_old = copy.deepcopy(gama) j = random.choice(list(omega_list)) # 随机选取一个核心对象 k = k + 1 Q = list() Q.append(j) gama.remove(j) while len(Q) > 0: q = Q[0] Q.remove(q) if len(neighbor_list[q]) >= min_Pts: delta = neighbor_list[q] & gama deltalist = list(delta) for i in range(len(delta)): Q.append(deltalist[i]) gama = gama - delta Ck = gama_old - gama Cklist = list(Ck) for i in range(len(Ck)): cluster[Cklist[i]] = k omega_list = omega_list - Ck return cluster
这是一个实现DBSCAN算法的Python函数。其中X是指定的数据集,eps是半径,min_Pts是密度阈值。函数返回一个列表cluster,用于存储每个样本所属的簇(-1表示噪声)。算法的具体实现如下:
1. 初始化一个空的簇集合,将所有样本标记为未访问状态。
2. 对于每个样本,计算其eps邻域,并记录邻域内点的个数。如果邻域内点的个数大于等于min_Pts,则将该样本标记为核心对象。
3. 随机选择一个核心对象,建立一个新的簇Ck,并将该核心对象从未访问集合gama中移除。
4. 利用BFS算法搜索核心对象的邻域,将邻域内的所有未访问样本加入队列Q中。
5. 如果队列Q不为空,则从队首取出一个样本,并计算其eps邻域。如果邻域内点的个数大于等于min_Pts,则将该样本标记为核心对象,并将其邻域内所有未访问点添加到队列Q中。将所有已经访问过的点从未访问集合gama中移除。
6. 将队列Q中的所有点加入簇Ck中,并将它们从未访问集合gama中移除。
7. 重复步骤3~6,直到所有核心对象都被访问过。
8. 返回簇集合。
校正以下代码的语法错误 def encode_edge(self, mode, node_history, node_history_st, edge_type, neighbors, neighbors_edge_value, first_history_indices, batch_size): max_hl = self.hyperparams['maximum_history_length'] max_neighbors = 0 for neighbor_states in neighbors: max_neighbors = max(max_neighbors, len(neighbor_states)) edge_states_list = list() # list of [#of neighbors, max_ht, state_dim] for i, neighbor_states in enumerate(neighbors): # Get neighbors for timestep in batch if len(neighbor_states) == 0: # There are no neighbors for edge type # TODO necessary? neighbor_state_length = int( np.sum([len(entity_dims) for entity_dims in self.state[edge_type[1]].values()]) ) edge_states_list.append(torch.zeros((1, max_hl + 1, neighbor_state_length), device=self.device)) else: edge_states_list.append(torch.stack(neighbor_states, dim=0).to(self.device)) # if self.hyperparams['edge_state_combine_method'] == 'sum': # Used in Structural-RNN to combine edges as well. op_applied_edge_states_list = list() for neighbors_state in edge_states_list: op_applied_edge_states_list.append(torch.sum(neighbors_state, dim=0))#torch.sum combined_neighbors = torch.stack(op_applied_edge_states_list, dim=0) # 获取combined_neighbors的第一个维度,代表邻接边的总数 combined_neighbors_0 = combined_neighbors.shape[0] # 创建全零矩阵s_next,形状为[batch_size, max_neighbors, combined_neighbors_0] s_next = torch.zeros((batch_size, max_neighbors, combined_neighbors_0), device=self.device) # 为s_next矩阵中每一行赋值为对应的combined_neighbors # for b in range(batch_size): # s_next[b, :len(neighbors[b]), :] = combined_neighbors[first_history_indices[b]] for i in range(batch_size): s_next[0, i, :] = batch_size[:] for i in range(max_neighbors): s_next[1, i, :] = max_neighbors[i, :] for i in range(combined_neighbors.shape[0]): s_next[2, i, :] = combined_neighbors
代码中缺少冒号,不是合法的 Python 代码。正确的代码应该是这样的:
```
def encode_edge(self, mode, node_history, node_history_st, edge_type, neighbors, neighbors_edge_value, first_history_indices, batch_size):
max_hl = self.hyperparams['maximum_history_length']
max_neighbors = 0
for neighbor_states in neighbors:
max_neighbors = max(max_neighbors, len(neighbor_states))
edge_states_list = list()
```
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