Fix Laplacian calculation in spectral partitioning

cpp/include/raft/spectral/laplacian.cuh → cpp/include/raft/sparse/linalg/laplacian.cuh

@@ -20,8 +20,8 @@
 #include <type_traits>
 
 namespace raft {
-namespace spectral {
-namespace matrix {
+namespace sparse {
+namespace linalg {
 namespace detail {
 
 /* Compute the graph Laplacian of an adjacency matrix
@@ -117,6 +117,6 @@ auto compute_graph_laplacian(
   return result;
 }
 
-}  // namespace matrix
-}  // namespace spectral
+}  // namespace linalg
+}  // namespace sparse
 }  // namespace raft

cpp/include/raft/spectral/detail/partition.hpp

@@ -21,7 +21,7 @@
 #include <raft/spectral/cluster_solvers.cuh>
 #include <raft/spectral/detail/spectral_util.cuh>
 #include <raft/spectral/eigen_solvers.cuh>
-#include <raft/spectral/laplacian.cuh>
+#include <raft/sparse/linalg/laplacian.cuh>
 #include <raft/spectral/matrix_wrappers.hpp>
 
 #include <cuda.h>
@@ -99,7 +99,7 @@ std::tuple<vertex_t, weight_t, vertex_t> partition(
 
   // Initialize Laplacian
   auto laplacian =
-    raft::spectral::matrix::compute_graph_laplacian(handle, csr_m.to_csr_matrix_view());
+    raft::sparse::linalg::compute_graph_laplacian(handle, csr_m.to_csr_matrix_view());
 
   auto eigen_config = eigen_solver.get_config();
   auto nEigVecs     = eigen_config.n_eigVecs;

cpp/tests/CMakeLists.txt

@@ -259,6 +259,7 @@ if(BUILD_TESTS)
     sparse/csr_transpose.cu
     sparse/degree.cu
     sparse/filter.cu
+    sparse/laplacian.cu
     sparse/masked_matmul.cu
     sparse/norm.cu
     sparse/normalize.cu

cpp/tests/sparse/laplacian.cu

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2020-2024, 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.
+ */
+
+#include <raft/core/device_csr_matrix.hpp>
+#include <raft/core/resource/cuda_stream.hpp>
+#include <raft/core/resources.hpp>
+#include <raft/sparse/linalg/laplacian.cuh>
+#include <raft/util/cudart_utils.hpp>
+
+#include <gtest/gtest.h>
+
+#include <vector>
+
+namespace raft {
+namespace sparse {
+namespace linalg {
+
+TEST(Raft, ComputeGraphLaplacian)
+{
+  // The following adjacency matrix will be used to allow for manual
+  // verification of results:
+  // [[0 1 1 1]
+  //  [1 0 0 1]
+  //  [1 0 0 0]
+  //  [1 1 0 0]]
+
+  auto data    = std::vector<float>{1, 1, 1, 1, 1, 1, 1, 1};
+  auto indices = std::vector<int>{1, 2, 3, 0, 3, 0, 0, 1};
+  auto indptr  = std::vector<int>{0, 3, 5, 6, 8};
+
+  auto res = raft::resources{};
+  auto adjacency_matrix =
+    make_device_csr_matrix<float>(res, int(indptr.size() - 1), int(indptr.size() - 1), data.size());
+  auto adjacency_structure = adjacency_matrix.structure_view();
+  raft::copy(adjacency_matrix.get_elements().data(),
+             &(data[0]),
+             data.size(),
+             raft::resource::get_cuda_stream(res));
+  raft::copy(adjacency_structure.get_indices().data(),
+             &(indices[0]),
+             indices.size(),
+             raft::resource::get_cuda_stream(res));
+  raft::copy(adjacency_structure.get_indptr().data(),
+             &(indptr[0]),
+             indptr.size(),
+             raft::resource::get_cuda_stream(res));
+  auto laplacian           = compute_graph_laplacian(res, adjacency_matrix.view());
+  auto laplacian_structure = laplacian.structure_view();
+  auto laplacian_data      = std::vector<float>(laplacian_structure.get_nnz());
+  auto laplacian_indices   = std::vector<int>(laplacian_structure.get_nnz());
+  auto laplacian_indptr    = std::vector<int>(laplacian_structure.get_n_rows() + 1);
+  raft::copy(&(laplacian_data[0]),
+             laplacian.get_elements().data(),
+             laplacian_structure.get_nnz(),
+             raft::resource::get_cuda_stream(res));
+  raft::copy(&(laplacian_indices[0]),
+             laplacian_structure.get_indices().data(),
+             laplacian_structure.get_nnz(),
+             raft::resource::get_cuda_stream(res));
+  raft::copy(&(laplacian_indptr[0]),
+             laplacian_structure.get_indptr().data(),
+             laplacian_structure.get_n_rows() + 1,
+             raft::resource::get_cuda_stream(res));
+  auto expected_data    = std::vector<float>{3, -1, -1, -1, -1, 2, -1, -1, 1, -1, -1, 2};
+  auto expected_indices = std::vector<int>{0, 1, 2, 3, 0, 1, 3, 0, 2, 0, 1, 3};
+  auto expected_indptr  = std::vector<int>{0, 4, 7, 9, 12};
+  raft::resource::sync_stream(res);
+
+  EXPECT_EQ(expected_data, laplacian_data);
+  EXPECT_EQ(expected_indices, laplacian_indices);
+  EXPECT_EQ(expected_indptr, laplacian_indptr);
+}
+
+}  // namespace linalg
+}  // namespace sparse
+}  // namespace raft

cpp/tests/sparse/spectral_matrix.cu

@@ -17,7 +17,7 @@
 #include <raft/core/resource/cuda_stream.hpp>
 #include <raft/core/resource/device_id.hpp>
 #include <raft/core/resources.hpp>
-#include <raft/spectral/laplacian.cuh>
+#include <raft/sparse/linalg/laplacian.cuh>
 #include <raft/spectral/matrix_wrappers.hpp>
 #include <raft/util/cudart_utils.hpp>
 
@@ -86,62 +86,6 @@ TEST(Raft, SpectralMatrices)
   EXPECT_ANY_THROW(cnstr_mm2());  // because of nullptr ptr args
 }
 
-TEST(Raft, ComputeGraphLaplacian)
-{
-  // The following adjacency matrix will be used to allow for manual
-  // verification of results:
-  // [[0 1 1 1]
-  //  [1 0 0 1]
-  //  [1 0 0 0]
-  //  [1 1 0 0]]
-
-  auto data    = std::vector<float>{1, 1, 1, 1, 1, 1, 1, 1};
-  auto indices = std::vector<int>{1, 2, 3, 0, 3, 0, 0, 1};
-  auto indptr  = std::vector<int>{0, 3, 5, 6, 8};
-
-  auto res = raft::resources{};
-  auto adjacency_matrix =
-    make_device_csr_matrix<float>(res, int(indptr.size() - 1), int(indptr.size() - 1), data.size());
-  auto adjacency_structure = adjacency_matrix.structure_view();
-  raft::copy(adjacency_matrix.get_elements().data(),
-             &(data[0]),
-             data.size(),
-             raft::resource::get_cuda_stream(res));
-  raft::copy(adjacency_structure.get_indices().data(),
-             &(indices[0]),
-             indices.size(),
-             raft::resource::get_cuda_stream(res));
-  raft::copy(adjacency_structure.get_indptr().data(),
-             &(indptr[0]),
-             indptr.size(),
-             raft::resource::get_cuda_stream(res));
-  auto laplacian           = compute_graph_laplacian(res, adjacency_matrix.view());
-  auto laplacian_structure = laplacian.structure_view();
-  auto laplacian_data      = std::vector<float>(laplacian_structure.get_nnz());
-  auto laplacian_indices   = std::vector<int>(laplacian_structure.get_nnz());
-  auto laplacian_indptr    = std::vector<int>(laplacian_structure.get_n_rows() + 1);
-  raft::copy(&(laplacian_data[0]),
-             laplacian.get_elements().data(),
-             laplacian_structure.get_nnz(),
-             raft::resource::get_cuda_stream(res));
-  raft::copy(&(laplacian_indices[0]),
-             laplacian_structure.get_indices().data(),
-             laplacian_structure.get_nnz(),
-             raft::resource::get_cuda_stream(res));
-  raft::copy(&(laplacian_indptr[0]),
-             laplacian_structure.get_indptr().data(),
-             laplacian_structure.get_n_rows() + 1,
-             raft::resource::get_cuda_stream(res));
-  auto expected_data    = std::vector<float>{3, -1, -1, -1, -1, 2, -1, -1, 1, -1, -1, 2};
-  auto expected_indices = std::vector<int>{0, 1, 2, 3, 0, 1, 3, 0, 2, 0, 1, 3};
-  auto expected_indptr  = std::vector<int>{0, 4, 7, 9, 12};
-  raft::resource::sync_stream(res);
-
-  EXPECT_EQ(expected_data, laplacian_data);
-  EXPECT_EQ(expected_indices, laplacian_indices);
-  EXPECT_EQ(expected_indptr, laplacian_indptr);
-}
-
 }  // namespace matrix
 }  // namespace spectral
 }  // namespace raft