如何获得树状图中节点下所有叶子的列表？

Question

我使用scipy.cluster.hierarchy.dendrogram制作了树状图，使用以下生成的数据：

a = np.random.multivariate_normal([10, 0], [[3, 1], [1, 4]], size=[100,])
b = np.random.multivariate_normal([0, 20], [[3, 1], [1, 4]], size=[50,])
c = np.random.multivariate_normal([8, 2], [[3, 1], [1, 4]], size=[80,])
X = np.concatenate((a, b, c),)

创建链接功能：

from scipy.cluster.hierarchy import dendrogram, linkage
Z = linkage(X, 'ward')

然后：

dendrogram(
    Z,
    truncate_mode='lastp',  # show only the last p merged clusters
    p=5,  # show only the last p merged clusters
    show_leaf_counts=False,  # otherwise numbers in brackets are counts
    leaf_rotation=90.,
    leaf_font_size=12.,
    show_contracted=True,  # to get a distribution impression in truncated branches
)

现在，我的数据中共有230个观测值，这些观测值被分为p = 5个簇。对于每个群集，我想拥有其中所有观测值的所有行索引的列表。另外，我想知道这5个群集之上的层次结构。

谢谢！

Answer 1

我是聚类和树状图的新手。因此，欢迎指出是否存在错误。

# put X in a dataframe
df = pd.DataFrame()
df['col1']=X[:,0]
df['col2']=X[:,1]

index=[]
for i in range(len(X)):
    elem = 'A' + str(i)
    index.append(elem)

df['index'] = index
print(df.shape)
df.head()

enter image description here

Z = linkage(X, 'ward')

dendrogram(
Z,
truncate_mode='lastp',  # show only the last p merged clusters
p=5,  # show only the last p merged clusters
show_leaf_counts=True,  # otherwise numbers in brackets are counts
leaf_rotation=90.,
leaf_font_size=12.,
show_contracted=True,  # to get a distribution impression in truncated branches
);
plt.show()

enter image description here

# retrieve elements in each cluster
label = fcluster(Z, 5, criterion='maxclust')

df_clst = pd.DataFrame()
df_clst['index']  = df['index']
df_clst['label']  = label

# print them
for i in range(5):
   elements = df_clst[df_clst['label']==i+1]['index'].tolist()  
   size = len(elements)
   print('\n Cluster {}: N = {}  {}'.format(i+1, size, elements))

enter image description here