from torch_geometric.utils import scatter_
[docs]def global_add_pool(x, batch, size=None):
r"""Returns batch-wise graph-level-outputs by adding node features
across the node dimension, so that for a single graph
:math:`\mathcal{G}_i` its output is computed by
.. math::
\mathbf{r}_i = \sum_{n=1}^{N_i} \mathbf{x}_n
Args:
x (Tensor): Node feature matrix
:math:`\mathbf{X} \in \mathbb{R}^{(N_1 + \ldots + N_B) \times F}`.
batch (LongTensor): Batch vector :math:`\mathbf{b} \in {\{ 0, \ldots,
B-1\}}^N`, which assigns each node to a specific example.
size (int, optional): Batch-size :math:`B`.
Automatically calculated if not given. (default: :obj:`None`)
:rtype: :class:`Tensor`
"""
size = batch.max().item() + 1 if size is None else size
return scatter_('add', x, batch, dim=0, dim_size=size)
[docs]def global_mean_pool(x, batch, size=None):
r"""Returns batch-wise graph-level-outputs by averaging node features
across the node dimension, so that for a single graph
:math:`\mathcal{G}_i` its output is computed by
.. math::
\mathbf{r}_i = \frac{1}{N_i} \sum_{n=1}^{N_i} \mathbf{x}_n
Args:
x (Tensor): Node feature matrix
:math:`\mathbf{X} \in \mathbb{R}^{(N_1 + \ldots + N_B) \times F}`.
batch (LongTensor): Batch vector :math:`\mathbf{b} \in {\{ 0, \ldots,
B-1\}}^N`, which assigns each node to a specific example.
size (int, optional): Batch-size :math:`B`.
Automatically calculated if not given. (default: :obj:`None`)
:rtype: :class:`Tensor`
"""
size = batch.max().item() + 1 if size is None else size
return scatter_('mean', x, batch, dim=0, dim_size=size)
[docs]def global_max_pool(x, batch, size=None):
r"""Returns batch-wise graph-level-outputs by taking the channel-wise
maximum across the node dimension, so that for a single graph
:math:`\mathcal{G}_i` its output is computed by
.. math::
\mathbf{r}_i = \mathrm{max}_{n=1}^{N_i} \, \mathbf{x}_n
Args:
x (Tensor): Node feature matrix
:math:`\mathbf{X} \in \mathbb{R}^{(N_1 + \ldots + N_B) \times F}`.
batch (LongTensor): Batch vector :math:`\mathbf{b} \in {\{ 0, \ldots,
B-1\}}^N`, which assigns each node to a specific example.
size (int, optional): Batch-size :math:`B`.
Automatically calculated if not given. (default: :obj:`None`)
:rtype: :class:`Tensor`
"""
size = batch.max().item() + 1 if size is None else size
return scatter_('max', x, batch, dim=0, dim_size=size)