Attention

The vector search and clustering algorithms in RAFT are being migrated to a new library dedicated to vector search called cuVS. We will continue to support the vector search algorithms in RAFT during this move, but will no longer update them after the RAPIDS 24.06 (June) release. We plan to complete the migration by RAPIDS 24.10 (October) release and they will be removed from RAFT altogether in the 24.12 (December) release.

Data Generation#

make_blobs#

#include <raft/random/make_blobs.cuh>

namespace raft::random

template<typename DataT, typename IdxT, typename layout> void make_blobs(raft::resources const &handle, raft::device_matrix_view<DataT, IdxT, layout> out, raft::device_vector_view<IdxT, IdxT> labels, IdxT n_clusters = 5, std::optional<raft::device_matrix_view<DataT, IdxT, layout>> centers = std::nullopt, std::optional<raft::device_vector_view<DataT, IdxT>> const cluster_std = std::nullopt, const DataT cluster_std_scalar = (DataT)1.0, bool shuffle = true, DataT center_box_min = (DataT)-10.0, DataT center_box_max = (DataT)10.0, uint64_t seed = 0ULL, GeneratorType type = GenPC)#

GPU-equivalent of sklearn.datasets.make_blobs.

Template Parameters:

DataT – output data type
IdxT – indexing arithmetic type

Parameters:

handle – [in] raft handle for managing expensive resources
out – [out] generated data [on device] [dim = n_rows x n_cols]
labels – [out] labels for the generated data [on device] [len = n_rows]
n_clusters – [in] number of clusters (or classes) to generate
centers – [in] centers of each of the cluster, pass a nullptr if you need this also to be generated randomly [on device] [dim = n_clusters x n_cols]
cluster_std – [in] standard deviation of each cluster center, pass a nullptr if this is to be read from the cluster_std_scalar. [on device] [len = n_clusters]
cluster_std_scalar – [in] if ‘cluster_std’ is nullptr, then use this as the std-dev across all dimensions.
shuffle – [in] shuffle the generated dataset and labels
center_box_min – [in] min value of box from which to pick cluster centers. Useful only if ‘centers’ is nullptr
center_box_max – [in] max value of box from which to pick cluster centers. Useful only if ‘centers’ is nullptr
seed – [in] seed for the RNG
type – [in] RNG type

make_regression#

#include <raft/random/make_regression.cuh>

namespace raft::random

template<typename DataT, typename IdxT> void make_regression(raft::resources const &handle, raft::device_matrix_view<DataT, IdxT, raft::row_major> out, raft::device_matrix_view<DataT, IdxT, raft::row_major> values, IdxT n_informative, std::optional<raft::device_matrix_view<DataT, IdxT, raft::row_major>> coef, DataT bias = DataT{}, IdxT effective_rank = static_cast<IdxT>(-1), DataT tail_strength = DataT{0.5}, DataT noise = DataT{}, bool shuffle = true, uint64_t seed = 0ULL, GeneratorType type = GenPC)#

GPU-equivalent of sklearn.datasets.make_regression as documented at: https://scikit-learn.org/stable/modules/generated/sklearn.datasets.make_regression.html.

Template Parameters:

DataT – Scalar type
IdxT – Index type

Parameters:

handle – [in] RAFT handle
out – [out] Row-major (samples, features) matrix to store the problem data
values – [out] Row-major (samples, targets) matrix to store the values for the regression problem
n_informative – [in] Number of informative features (non-zero coefficients)
coef – [out] If present, a row-major (features, targets) matrix to store the coefficients used to generate the values for the regression problem
bias – [in] A scalar that will be added to the values
effective_rank – [in] The approximate rank of the data matrix (used to create correlations in the data). -1 is the code to use well-conditioned data
tail_strength – [in] The relative importance of the fat noisy tail of the singular values profile if effective_rank is not -1
noise – [in] Standard deviation of the Gaussian noise applied to the output
shuffle – [in] Shuffle the samples and the features
seed – [in] Seed for the random number generator
type – [in] Random generator type

rmat#

#include <raft/random/rmat_rectangular_generator.cuh>

namespace raft::random

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(raft::resources const &handle, raft::random::RngState &r, raft::device_vector_view<const ProbT, IdxT> theta, raft::device_mdspan<IdxT, raft::extents<IdxT, raft::dynamic_extent, 2>, raft::row_major> out, raft::device_vector_view<IdxT, IdxT> out_src, raft::device_vector_view<IdxT, IdxT> out_dst, IdxT r_scale, IdxT c_scale)#

Generate a bipartite RMAT graph for a rectangular adjacency matrix.

This is the most general of several overloads of rmat_rectangular_gen in this file, and thus has the most detailed documentation.

We call the r_scale != c_scale case the “rectangular adjacency matrix” case (in other words, generating bipartite graphs). In this case, at depth >= r_scale, the distribution is assumed to be:

[theta[4 * depth] + theta[4 * depth + 2], theta[4 * depth + 1] + theta[4 * depth + 3]; 0, 0].

Then for depth >= c_scale, the distribution is assumed to be:

[theta[4 * depth] + theta[4 * depth + 1], 0; theta[4 * depth + 2] + theta[4 * depth + 3], 0].

Note

This can generate duplicate edges and self-loops. It is the responsibility of the caller to clean them up accordingly.

Note

This also only generates directed graphs. If undirected graphs are needed, then a separate post-processing step is expected to be done by the caller.

Template Parameters:

IdxT – Type of each node index
ProbT – Data type used for probability distributions (either fp32 or fp64)

Parameters:

handle – [in] RAFT handle, containing the CUDA stream on which to schedule work
r – [in] underlying state of the random generator. Especially useful when one wants to call this API for multiple times in order to generate a larger graph. For that case, just create this object with the initial seed once and after every call continue to pass the same object for the successive calls.
out – [out] Generated edgelist [on device], packed in array-of-structs fashion. In each row, the first element is the source node id, and the second element is the destination node id.
out_src – [out] Source node id’s [on device].
out_dst – [out] Destination node id’s [on device]. out_src and out_dst together form the struct-of-arrays representation of the same output data as out.
theta – [in] distribution of each quadrant at each level of resolution. Since these are probabilities, each of the 2x2 matrices for each level of the RMAT must sum to one. [on device] [dim = max(r_scale, c_scale) x 2 x 2]. Of course, it is assumed that each of the group of 2 x 2 numbers all sum up to 1.
r_scale – [in] 2^r_scale represents the number of source nodes
c_scale – [in] 2^c_scale represents the number of destination nodes

Pre:

out.extent(0) == 2 *out_src.extent(0)istrue @preout_src.extent(0) == out_dst.extent(0)istrue`

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(raft::resources const &handle, raft::random::RngState &r, raft::device_vector_view<const ProbT, IdxT> theta, raft::device_vector_view<IdxT, IdxT> out_src, raft::device_vector_view<IdxT, IdxT> out_dst, IdxT r_scale, IdxT c_scale)#

Overload of rmat_rectangular_gen that only generates the struct-of-arrays (two vectors) output representation.

This overload only generates the struct-of-arrays (two vectors) output representation: output vector out_src of source node id’s, and output vector out_dst of destination node id’s.

Pre:: out_src.extent(0) == out_dst.extent(0) is true

Overload of rmat_rectangular_gen that only generates the array-of-structs (one vector) output representation.

This overload only generates the array-of-structs (one vector) output representation: a single output vector out, where in each row, the first element is the source node id, and the second element is the destination node id.

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(raft::resources const &handle, raft::random::RngState &r, raft::device_mdspan<IdxT, raft::extents<IdxT, raft::dynamic_extent, 2>, raft::row_major> out, raft::device_vector_view<IdxT, IdxT> out_src, raft::device_vector_view<IdxT, IdxT> out_dst, ProbT a, ProbT b, ProbT c, IdxT r_scale, IdxT c_scale)#

Overload of rmat_rectangular_gen that assumes the same a, b, c, d probability distributions across all the scales, and takes all three output vectors (out with the array-of-structs output representation, and out_src and out_dst with the struct-of-arrays output representation).

a, b, andc effectively replace the above overloads theta parameter.

Pre:: out.extent(0) == 2 *out_src.extent(0)istrue @preout_src.extent(0) == out_dst.extent(0)istrue`

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(raft::resources const &handle, raft::random::RngState &r, raft::device_vector_view<IdxT, IdxT> out_src, raft::device_vector_view<IdxT, IdxT> out_dst, ProbT a, ProbT b, ProbT c, IdxT r_scale, IdxT c_scale)#

Overload of rmat_rectangular_gen that assumes the same a, b, c, d probability distributions across all the scales, and takes only two output vectors (the struct-of-arrays output representation).

a, b, andc effectively replace the above overloads theta parameter.

Pre:: out_src.extent(0) == out_dst.extent(0) is true

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(raft::resources const &handle, raft::random::RngState &r, raft::device_mdspan<IdxT, raft::extents<IdxT, raft::dynamic_extent, 2>, raft::row_major> out, ProbT a, ProbT b, ProbT c, IdxT r_scale, IdxT c_scale)#

Overload of rmat_rectangular_gen that assumes the same a, b, c, d probability distributions across all the scales, and takes only one output vector (the array-of-structs output representation).

a, b, andc effectively replace the above overloads theta parameter.

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(IdxT *out, IdxT *out_src, IdxT *out_dst, const ProbT *theta, IdxT r_scale, IdxT c_scale, IdxT n_edges, cudaStream_t stream, raft::random::RngState &r)#

Legacy overload of rmat_rectangular_gen taking raw arrays instead of mdspan.

Template Parameters:

IdxT – type of each node index
ProbT – data type used for probability distributions (either fp32 or fp64)

Parameters:

out – [out] generated edgelist [on device] [dim = n_edges x 2]. In each row the first element is the source node id, and the second element is the destination node id. If you don’t need this output then pass a nullptr in its place.
out_src – [out] list of source node id’s [on device] [len = n_edges]. If you don’t need this output then pass a nullptr in its place.
out_dst – [out] list of destination node id’s [on device] [len = n_edges]. If you don’t need this output then pass a nullptr in its place.
theta – [in] distribution of each quadrant at each level of resolution. Since these are probabilities, each of the 2x2 matrices for each level of the RMAT must sum to one. [on device] [dim = max(r_scale, c_scale) x 2 x 2]. Of course, it is assumed that each of the group of 2 x 2 numbers all sum up to 1.
r_scale – [in] 2^r_scale represents the number of source nodes
c_scale – [in] 2^c_scale represents the number of destination nodes
n_edges – [in] number of edges to generate
stream – [in] cuda stream on which to schedule the work
r – [in] underlying state of the random generator. Especially useful when one wants to call this API for multiple times in order to generate a larger graph. For that case, just create this object with the initial seed once and after every call continue to pass the same object for the successive calls.

template<typename IdxT, typename ProbT> void rmat_rectangular_gen(IdxT *out, IdxT *out_src, IdxT *out_dst, ProbT a, ProbT b, ProbT c, IdxT r_scale, IdxT c_scale, IdxT n_edges, cudaStream_t stream, raft::random::RngState &r)#: Legacy overload of rmat_rectangular_gen taking raw arrays instead of mdspan. This overload assumes the same a, b, c, d probability distributions across all the scales.