/*
 * Copyright (c) 2019-2021, NVIDIA CORPORATION.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <cuml/cuml.hpp>

namespace ML {

namespace Spectral {

/**
   * Given a COO formatted (symmetric) knn graph, this function
   * computes the spectral embeddings (lowest n_components
   * eigenvectors), using Lanczos min cut algorithm.
   * @param handle cuml handle
   * @param rows source vertices of knn graph (size nnz)
   * @param cols destination vertices of knn graph (size nnz)
   * @param vals edge weights connecting vertices of knn graph (size nnz)
   * @param nnz size of rows/cols/vals
   * @param n number of samples in X
   * @param n_components the number of components to project the X into
   * @param out output array for embedding (size n*n_comonents)
   */
void fit_embedding(const raft::handle_t &handle, int *rows, int *cols,
                   float *vals, int nnz, int n, int n_components, float *out);

}  // namespace Spectral
}  // namespace ML
