sklearn：半监督学习 - LabelSpreadingModel 内存错误答案

【问题标题】：sklearn: semi-supervised learning - LabelSpreadingModel memory errorsklearn：半监督学习 - LabelSpreadingModel 内存错误
【发布时间】：2017-02-27 02:08:21
【问题描述】：

我使用sklearn LabelSpreadingModel如下：

label_spreading_model = LabelSpreading()
model_s = label_spreading_model.fit(my_inputs, labels)

但我收到以下错误：

   MemoryErrorTraceback (most recent call last)
    <ipython-input-17-73adbf1fc908> in <module>()
         11 
         12 label_spreading_model = LabelSpreading()
    ---> 13 model_s = label_spreading_model.fit(my_inputs, labels)

    /usr/local/lib/python2.7/dist-packages/sklearn/semi_supervised/label_propagation.pyc in fit(self, X, y)
        224 
        225         # actual graph construction (implementations should override this)
    --> 226         graph_matrix = self._build_graph()
        227 
        228         # label construction

    /usr/local/lib/python2.7/dist-packages/sklearn/semi_supervised/label_propagation.pyc in _build_graph(self)
        455         affinity_matrix = self._get_kernel(self.X_)
        456         laplacian = graph_laplacian(affinity_matrix, normed=True)
    --> 457         laplacian = -laplacian
        458         if sparse.isspmatrix(laplacian):
        459             diag_mask = (laplacian.row == laplacian.col)

    MemoryError:

我的输入矩阵的拉普拉斯算子似乎有问题。是否有任何我可以配置的参数或任何可以避免此错误的更改？谢谢！

【问题讨论】：

标签： python-2.7 machine-learning scikit-learn

【解决方案1】：

很明显：您的 PC 内存不足。

由于您没有设置任何参数，因此默认使用 rbf-kernel (proof)。

摘自scikit-learn's docs：

The RBF kernel will produce a fully connected graph which is represented in
memory by a dense matrix. This matrix may be very large and combined with the 
cost of performing a full matrix multiplication calculation for each iteration
of the algorithm can lead to prohibitively long running times

也许以下（上述文档中的下一句）会有所帮助：

On the other hand, the KNN kernel will produce a much more memory-friendly 
sparse matrix which can drastically reduce running times.

但我不知道您的数据、PC 配置等。而且只能猜测...

【讨论】：