<p>我在尝试用sklearn、pandas和numpy进行多维缩放。Im使用的数据文件有10个数字列,没有丢失的值。我试着用sklearn把这个10维数据可视化成2维,流形的多维标度如下:</p>
<pre><code>import numpy as np
import pandas as pd
from sklearn import manifold
from sklearn.metrics import euclidean_distances
seed = np.random.RandomState(seed=3)
data = pd.read_csv('data/big-file.csv')
# start small dont take all the data,
# its about 200k records
subset = data[:10000]
similarities = euclidean_distances(subset)
mds = manifold.MDS(n_components=2, max_iter=3000, eps=1e-9,
random_state=seed, dissimilarity="precomputed", n_jobs=1)
pos = mds.fit(similarities).embedding_
</code></pre>
<p>但我得到这个值错误:</p>
<pre><code>Traceback (most recent call last):
File "demo/mds-demo.py", line 18, in <module>
pos = mds.fit(similarities).embedding_
File "/Users/dwilliams/Desktop/Anaconda/lib/python2.7/site-packages/sklearn/manifold/mds.py", line 360, in fit
self.fit_transform(X, init=init)
File "/Users/dwilliams/Desktop/Anaconda/lib/python2.7/site-packages/sklearn/manifold/mds.py", line 395, in fit_transform
eps=self.eps, random_state=self.random_state)
File "/Users/dwilliams/Desktop/Anaconda/lib/python2.7/site-packages/sklearn/manifold/mds.py", line 242, in smacof
eps=eps, random_state=random_state)
File "/Users/dwilliams/Desktop/Anaconda/lib/python2.7/site-packages/sklearn/manifold/mds.py", line 73, in _smacof_single
raise ValueError("similarities must be symmetric")
ValueError: similarities must be symmetric
</code></pre>
<p>我认为欧氏距离返回了一个对称矩阵。我做错了什么?我该怎么解决?</p>