[REVIEW] Expose sparse distances via semiring to Python API

cpp/cmake/Dependencies.cmake

@@ -39,7 +39,7 @@ else(DEFINED ENV{RAFT_PATH})
 
   ExternalProject_Add(raft
     GIT_REPOSITORY    https://github.com/rapidsai/raft.git
-    GIT_TAG           a57cf7df757b24230454e442c83f8491f97a4843
+    GIT_TAG           d1fd927bc4ec67bfd765620b5fa93f17c54cfa70
     PREFIX            ${RAFT_DIR}
     CONFIGURE_COMMAND ""
     BUILD_COMMAND     ""

cpp/include/cuml/metrics/metrics.hpp

@@ -321,5 +321,18 @@ void pairwise_distance(const raft::handle_t &handle, const float *x,
                        raft::distance::DistanceType metric,
                        bool isRowMajor = true);
 
+void pairwiseDistance_sparse(const raft::handle_t &handle, double *x, double *y,
+                             double *dist, int x_nrows, int y_nrows, int n_cols,
+                             int x_nnz, int y_nnz, int *x_indptr, int *y_indptr,
+                             int *x_indices, int *y_indices,
+                             raft::distance::DistanceType metric,
+                             float metric_arg);
+void pairwiseDistance_sparse(const raft::handle_t &handle, float *x, float *y,
+                             float *dist, int x_nrows, int y_nrows, int n_cols,
+                             int x_nnz, int y_nnz, int *x_indptr, int *y_indptr,
+                             int *x_indices, int *y_indices,
+                             raft::distance::DistanceType metric,
+                             float metric_arg);
+
 }  // namespace Metrics
 }  // namespace ML

cpp/src/metrics/pairwise_distance.cu

@@ -1,6 +1,6 @@
 
 /*
- * Copyright (c) 2019-2020, NVIDIA CORPORATION.
+ * 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.
@@ -15,8 +15,10 @@
  * limitations under the License.
  */
 
+#include <raft/sparse/distance/common.h>
 #include <cuml/metrics/metrics.hpp>
 #include <metrics/pairwise_distance.cuh>
+#include <raft/sparse/distance/distance.cuh>
 
 namespace ML {
 
@@ -37,5 +39,59 @@ void pairwise_distance(const raft::handle_t &handle, const float *x,
                                        handle.get_stream(), isRowMajor);
 }
 
+template <typename value_idx = int, typename value_t = float>
+void pairwiseDistance_sparse(const raft::handle_t &handle, value_t *x,
+                             value_t *y, value_t *dist, value_idx x_nrows,
+                             value_idx y_nrows, value_idx n_cols,
+                             value_idx x_nnz, value_idx y_nnz,
+                             value_idx *x_indptr, value_idx *y_indptr,
+                             value_idx *x_indices, value_idx *y_indices,
+                             raft::distance::DistanceType metric,
+                             float metric_arg) {
+  raft::sparse::distance::distances_config_t<value_idx, value_t> dist_config;
+
+  dist_config.b_nrows = x_nrows;
+  dist_config.b_ncols = n_cols;
+  dist_config.b_nnz = x_nnz;
+  dist_config.b_indptr = x_indptr;
+  dist_config.b_indices = x_indices;
+  dist_config.b_data = x;
+
+  dist_config.a_nrows = y_nrows;
+  dist_config.a_ncols = n_cols;
+  dist_config.a_nnz = y_nnz;
+  dist_config.a_indptr = y_indptr;
+  dist_config.a_indices = y_indices;
+  dist_config.a_data = y;
+
+  dist_config.handle = handle.get_cusparse_handle();
+  dist_config.allocator = handle.get_device_allocator();
+  dist_config.stream = handle.get_stream();
+
+  raft::sparse::distance::pairwiseDistance(dist, dist_config, metric,
+                                           metric_arg);
+}
+
+void pairwiseDistance_sparse(const raft::handle_t &handle, float *x, float *y,
+                             float *dist, int x_nrows, int y_nrows, int n_cols,
+                             int x_nnz, int y_nnz, int *x_indptr, int *y_indptr,
+                             int *x_indices, int *y_indices,
+                             raft::distance::DistanceType metric,
+                             float metric_arg) {
+  pairwiseDistance_sparse<int, float>(handle, x, y, dist, x_nrows, y_nrows,
+                                      n_cols, x_nnz, y_nnz, x_indptr, y_indptr,
+                                      x_indices, y_indices, metric, metric_arg);
+}
+
+void pairwiseDistance_sparse(const raft::handle_t &handle, double *x, double *y,
+                             double *dist, int x_nrows, int y_nrows, int n_cols,
+                             int x_nnz, int y_nnz, int *x_indptr, int *y_indptr,
+                             int *x_indices, int *y_indices,
+                             raft::distance::DistanceType metric,
+                             float metric_arg) {
+  pairwiseDistance_sparse<int, double>(
+    handle, x, y, dist, x_nrows, y_nrows, n_cols, x_nnz, y_nnz, x_indptr,
+    y_indptr, x_indices, y_indices, metric, metric_arg);
+}
 }  // namespace Metrics
 }  // namespace ML

python/cuml/metrics/__init__.py

@@ -32,6 +32,8 @@
     cython_mutual_info_score as mutual_info_score
 from cuml.metrics.confusion_matrix import confusion_matrix
 from cuml.metrics.cluster.entropy import cython_entropy as entropy
-from cuml.metrics.pairwise_distances import pairwise_distances, \
-    PAIRWISE_DISTANCE_METRICS
+from cuml.metrics.pairwise_distances import pairwise_distances
+from cuml.metrics.pairwise_distances import sparse_pairwise_distances
+from cuml.metrics.pairwise_distances import PAIRWISE_DISTANCE_METRICS
+from cuml.metrics.pairwise_distances import PAIRWISE_DISTANCE_SPARSE_METRICS
 from cuml.metrics.hinge_loss import hinge_loss