methods.py 文件源码

def _extract_pairwise(self, X, y, n, is_train=True):
        if self.cache is not None and (n, True, is_train) in self.cache:
            return self.cache[n, True, is_train]

        if not hasattr(X, "shape"):
            raise ValueError("Precomputed kernels or affinity matrices have "
                             "to be passed as arrays or sparse matrices.")
        if X.shape[0] != X.shape[1]:
            raise ValueError("X should be a square kernel matrix")
        train, test = self.splits[n]
        result = X[np.ix_(train if is_train else test, train)]

        if self.cache is not None:
            self.cache[n, True, is_train] = result
        return result