recsys.py 文件源码

def _refit(self, X):
        n_samples, n_features = X.shape
        for i in range(n_samples):
            X_subset = X.data[X.indptr[i]:X.indptr[i + 1]]
            subset = X.indices[X.indptr[i]:X.indptr[i + 1]]
            len_subset = subset.shape[0]
            reduction = n_features / len_subset
            components_subset = self.components_[:, subset]
            Dx = components_subset.dot(X_subset)
            G = components_subset.dot(components_subset.T)
            G.flat[::self.n_components + 1] += self.alpha / reduction
            self.code_[i] = linalg.solve(G, Dx)