Function bipartite_from_scipy

python/dgl/convert.py:1149–1243

Create a uni-directional bipartite graph from a SciPy sparse matrix and return. The created graph will have two types of nodes ``utype`` and ``vtype`` as well as one edge type ``etype`` whose edges are from ``utype`` to ``vtype``. Parameters ---------- sp_mat : scipy.sparse.spm

(
    sp_mat, utype, etype, vtype, eweight_name=None, idtype=None, device=None
)

def bipartite_from_scipy(
    sp_mat, utype, etype, vtype, eweight_name=None, idtype=None, device=None
):
    """Create a uni-directional bipartite graph from a SciPy sparse matrix and return.

    The created graph will have two types of nodes ``utype`` and ``vtype`` as well as one
    edge type ``etype`` whose edges are from ``utype`` to ``vtype``.

    Parameters
    ----------
    sp_mat : scipy.sparse.spmatrix
        The graph adjacency matrix. Each nonzero entry ``sp_mat[i, j]``
        represents an edge from node ``i`` of type :attr:`utype` to ``j`` of type :attr:`vtype`.
        Let the matrix shape be ``(N, M)``. There will be ``N`` nodes of type :attr:`utype`
        and ``M`` nodes of type ``vtype`` in the resulting graph.
    utype : str, optional
        The name of the source node type.
    etype : str, optional
        The name of the edge type.
    vtype : str, optional
        The name of the destination node type.
    eweight_name : str, optional
        The edata name for storing the nonzero values of :attr:`sp_mat`.
        If given, DGL will store the nonzero values of :attr:`sp_mat` in ``edata[eweight_name]``
        of the returned graph.
    idtype : int32 or int64, optional
        The data type for storing the structure-related graph information such as node and
        edge IDs. It should be a framework-specific data type object (e.g., ``torch.int32``).
        By default, DGL uses int64.
    device : device context, optional
        The device of the resulting graph. It should be a framework-specific device object
        (e.g., ``torch.device``). By default, DGL stores the graph on CPU.

    Returns
    -------
    DGLGraph
        The created graph.

    Notes
    -----
    1. The function supports all kinds of SciPy sparse matrix classes (e.g.,
       :class:`scipy.sparse.csr.csr_matrix`). It converts the input matrix to the COOrdinate
       format using :func:`scipy.sparse.spmatrix.tocoo` before creates a :class:`DGLGraph`.
       Creating from a :class:`scipy.sparse.coo.coo_matrix` is hence the most efficient way.
    2. DGL internally maintains multiple copies of the graph structure in different sparse
       formats and chooses the most efficient one depending on the computation invoked.
       If memory usage becomes an issue in the case of large graphs, use
       :func:`dgl.DGLGraph.formats` to restrict the allowed formats.

    Examples
    --------

    The following example uses PyTorch backend.

    >>> import dgl
    >>> import numpy as np
    >>> import torch
    >>> from scipy.sparse import coo_matrix