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Zihao Ye 93ac29ce34 [Refactor] Unify DGLGraph, BatchedDGLGraph and DGLSubGraph (#1216)
* upd

* upd

* upd

* lint

* fix

* fix test

* fix

* fix

* upd

* upd

* upd

* upd

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* upd tutorial

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* fix kg

* upd doc organization

* refresh test

* upd

* refactor doc

* fix lint

Co-authored-by: Minjie Wang <minjie.wang@nyu.edu>
2020-03-05 18:03:57 +08:00

1132 行
35 KiB
Python

"""Classes and functions for batching multiple graphs together."""
from __future__ import absolute_import
import numpy as np
from .base import DGLError
from . import backend as F
__all__ = ['sum_nodes', 'sum_edges', 'mean_nodes', 'mean_edges',
'max_nodes', 'max_edges', 'softmax_nodes', 'softmax_edges',
'broadcast_nodes', 'broadcast_edges', 'topk_nodes', 'topk_edges']
READOUT_ON_ATTRS = {
'nodes': ('ndata', 'batch_num_nodes', 'number_of_nodes'),
'edges': ('edata', 'batch_num_edges', 'number_of_edges'),
}
def _sum_on(graph, typestr, feat, weight):
"""Internal function to sum node or edge features.
Parameters
----------
graph : DGLGraph
The graph.
typestr : str
'nodes' or 'edges'
feat : str
The feature field name.
weight : str
The weight field name.
Returns
-------
tensor
The (weighted) summed node or edge features.
"""
data_attr, batch_num_objs_attr, _ = READOUT_ON_ATTRS[typestr]
data = getattr(graph, data_attr)
feat = data[feat]
if weight is not None:
weight = data[weight]
weight = F.reshape(weight, (-1,) + (1,) * (F.ndim(feat) - 1))
feat = weight * feat
n_graphs = graph.batch_size
batch_num_objs = getattr(graph, batch_num_objs_attr)
seg_id = F.zerocopy_from_numpy(np.arange(n_graphs, dtype='int64').repeat(batch_num_objs))
seg_id = F.copy_to(seg_id, F.context(feat))
y = F.unsorted_1d_segment_sum(feat, seg_id, n_graphs, 0)
return y
def sum_nodes(graph, feat, weight=None):
"""Sums all the values of node field :attr:`feat` in :attr:`graph`, optionally
multiplies the field by a scalar node field :attr:`weight`.
Parameters
----------
graph : DGLGraph.
The graph.
feat : str
The feature field.
weight : str, optional
The weight field. If None, no weighting will be performed,
otherwise, weight each node feature with field :attr:`feat`.
for summation. The weight feature associated in the :attr:`graph`
should be a tensor of shape ``[graph.number_of_nodes(), 1]``.
Returns
-------
tensor
The summed tensor.
Notes
-----
Return a stacked tensor with an extra first dimension whose size equals
batch size of the input graph.
The i-th row of the stacked tensor contains the readout result of the
i-th graph in the batched graph. If a graph has no nodes,
a zero tensor with the same shape is returned at the corresponding row.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
node features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.ndata['h'] = th.tensor([[1.], [2.]])
>>> g1.ndata['w'] = th.tensor([[3.], [6.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.ndata['h'] = th.tensor([[1.], [2.], [3.]])
Sum over node attribute :attr:`h` without weighting for each graph in a
batched graph.
>>> bg = dgl.batch([g1, g2], node_attrs='h')
>>> dgl.sum_nodes(bg, 'h')
tensor([[3.], # 1 + 2
[6.]]) # 1 + 2 + 3
Sum node attribute :attr:`h` with weight from node attribute :attr:`w`
for a single graph.
>>> dgl.sum_nodes(g1, 'h', 'w')
tensor([[15.]]) # 1 * 3 + 2 * 6
See Also
--------
mean_nodes
sum_edges
mean_edges
"""
return _sum_on(graph, 'nodes', feat, weight)
def sum_edges(graph, feat, weight=None):
"""Sums all the values of edge field :attr:`feat` in :attr:`graph`,
optionally multiplies the field by a scalar edge field :attr:`weight`.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
weight : str, optional
The weight field. If None, no weighting will be performed,
otherwise, weight each edge feature with field :attr:`feat`.
for summation. The weight feature associated in the :attr:`graph`
should be a tensor of shape ``[graph.number_of_edges(), 1]``.
Returns
-------
tensor
The summed tensor.
Notes
-----
Return a stacked tensor with an extra first dimension whose size equals
batch size of the input graph.
The i-th row of the stacked tensor contains the readout result of the
i-th graph in the batched graph. If a graph has no edges,
a zero tensor with the same shape is returned at the corresponding row.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
edge features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.add_edges([0, 1], [1, 0])
>>> g1.edata['h'] = th.tensor([[1.], [2.]])
>>> g1.edata['w'] = th.tensor([[3.], [6.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.add_edges([0, 1, 2], [1, 2, 0])
>>> g2.edata['h'] = th.tensor([[1.], [2.], [3.]])
Sum over edge attribute :attr:`h` without weighting for each graph in a
batched graph.
>>> bg = dgl.batch([g1, g2], edge_attrs='h')
>>> dgl.sum_edges(bg, 'h')
tensor([[3.], # 1 + 2
[6.]]) # 1 + 2 + 3
Sum edge attribute :attr:`h` with weight from edge attribute :attr:`w`
for a single graph.
>>> dgl.sum_edges(g1, 'h', 'w')
tensor([[15.]]) # 1 * 3 + 2 * 6
See Also
--------
sum_nodes
mean_nodes
mean_edges
"""
return _sum_on(graph, 'edges', feat, weight)
def _mean_on(graph, typestr, feat, weight):
"""Internal function to sum node or edge features.
Parameters
----------
graph : DGLGraph
The graph.
typestr : str
'nodes' or 'edges'
feat : str
The feature field name.
weight : str
The weight field name.
Returns
-------
tensor
The (weighted) summed node or edge features.
"""
data_attr, batch_num_objs_attr, _ = READOUT_ON_ATTRS[typestr]
data = getattr(graph, data_attr)
feat = data[feat]
if weight is not None:
weight = data[weight]
weight = F.reshape(weight, (-1,) + (1,) * (F.ndim(feat) - 1))
feat = weight * feat
n_graphs = graph.batch_size
batch_num_objs = getattr(graph, batch_num_objs_attr)
seg_id = F.zerocopy_from_numpy(np.arange(n_graphs, dtype='int64').repeat(batch_num_objs))
seg_id = F.copy_to(seg_id, F.context(feat))
if weight is not None:
w = F.unsorted_1d_segment_sum(weight, seg_id, n_graphs, 0)
y = F.unsorted_1d_segment_sum(feat, seg_id, n_graphs, 0)
y = y / w
else:
y = F.unsorted_1d_segment_mean(feat, seg_id, n_graphs, 0)
return y
def mean_nodes(graph, feat, weight=None):
"""Averages all the values of node field :attr:`feat` in :attr:`graph`,
optionally multiplies the field by a scalar node field :attr:`weight`.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
weight : str, optional
The weight field. If None, no weighting will be performed,
otherwise, weight each node feature with field :attr:`feat`.
for calculating mean. The weight feature associated in the :attr:`graph`
should be a tensor of shape ``[graph.number_of_nodes(), 1]``.
Returns
-------
tensor
The averaged tensor.
Notes
-----
Return a stacked tensor with an extra first dimension whose size equals
batch size of the input graph.
The i-th row of the stacked tensor contains the readout result of
the i-th graph in the batch. If a graph has no nodes,
a zero tensor with the same shape is returned at the corresponding row.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
node features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.ndata['h'] = th.tensor([[1.], [2.]])
>>> g1.ndata['w'] = th.tensor([[3.], [6.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.ndata['h'] = th.tensor([[1.], [2.], [3.]])
Average over node attribute :attr:`h` without weighting for each graph in a
batched graph.
>>> bg = dgl.batch([g1, g2], node_attrs='h')
>>> dgl.mean_nodes(bg, 'h')
tensor([[1.5000], # (1 + 2) / 2
[2.0000]]) # (1 + 2 + 3) / 3
Sum node attribute :attr:`h` with normalized weight from node attribute :attr:`w`
for a single graph.
>>> dgl.mean_nodes(g1, 'h', 'w') # h1 * (w1 / (w1 + w2)) + h2 * (w2 / (w1 + w2))
tensor([[1.6667]]) # 1 * (3 / (3 + 6)) + 2 * (6 / (3 + 6))
See Also
--------
sum_nodes
sum_edges
mean_edges
"""
return _mean_on(graph, 'nodes', feat, weight)
def mean_edges(graph, feat, weight=None):
"""Averages all the values of edge field :attr:`feat` in :attr:`graph`,
optionally multiplies the field by a scalar edge field :attr:`weight`.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
weight : optional, str
The weight field. If None, no weighting will be performed,
otherwise, weight each edge feature with field :attr:`feat`.
for calculating mean. The weight feature associated in the :attr:`graph`
should be a tensor of shape ``[graph.number_of_edges(), 1]``.
Returns
-------
tensor
The averaged tensor.
Notes
-----
Return a stacked tensor with an extra first dimension whose size equals
batch size of the input graph.
The i-th row of the stacked tensor contains the readout result of
the i-th graph in the batched graph. If a graph has no edges,
a zero tensor with the same shape is returned at the corresponding row.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
edge features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.add_edges([0, 1], [1, 0])
>>> g1.edata['h'] = th.tensor([[1.], [2.]])
>>> g1.edata['w'] = th.tensor([[3.], [6.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.add_edges([0, 1, 2], [1, 2, 0])
>>> g2.edata['h'] = th.tensor([[1.], [2.], [3.]])
Average over edge attribute :attr:`h` without weighting for each graph in a
batched graph.
>>> bg = dgl.batch([g1, g2], edge_attrs='h')
>>> dgl.mean_edges(bg, 'h')
tensor([[1.5000], # (1 + 2) / 2
[2.0000]]) # (1 + 2 + 3) / 3
Sum edge attribute :attr:`h` with normalized weight from edge attribute :attr:`w`
for a single graph.
>>> dgl.mean_edges(g1, 'h', 'w') # h1 * (w1 / (w1 + w2)) + h2 * (w2 / (w1 + w2))
tensor([[1.6667]]) # 1 * (3 / (3 + 6)) + 2 * (6 / (3 + 6))
See Also
--------
sum_nodes
mean_nodes
sum_edges
"""
return _mean_on(graph, 'edges', feat, weight)
def _max_on(graph, typestr, feat):
"""Internal function to take elementwise maximum
over node or edge features.
Parameters
----------
graph : DGLGraph
The graph.
typestr : str
'nodes' or 'edges'
feat : str
The feature field name.
Returns
-------
tensor
The (weighted) summed node or edge features.
"""
data_attr, batch_num_objs_attr, _ = READOUT_ON_ATTRS[typestr]
data = getattr(graph, data_attr)
feat = data[feat]
# TODO: the current solution pads the different graph sizes to the same,
# a more efficient way is to use segment max, we need to implement it in
# the future.
batch_num_objs = getattr(graph, batch_num_objs_attr)
feat = F.pad_packed_tensor(feat, batch_num_objs, -float('inf'))
return F.max(feat, 1)
def _softmax_on(graph, typestr, feat):
"""Internal function of applying batch-wise graph-level softmax
over node or edge features of a given field.
Parameters
----------
graph : DGLGraph
The graph
typestr : str
'nodes' or 'edges'
feat : str
The feature field name.
Returns
-------
tensor
The obtained tensor.
"""
data_attr, batch_num_objs_attr, _ = READOUT_ON_ATTRS[typestr]
data = getattr(graph, data_attr)
feat = data[feat]
# TODO: the current solution pads the different graph sizes to the same,
# a more efficient way is to use segment sum/max, we need to implement
# it in the future.
batch_num_objs = getattr(graph, batch_num_objs_attr)
feat = F.pad_packed_tensor(feat, batch_num_objs, -float('inf'))
feat = F.softmax(feat, 1)
return F.pack_padded_tensor(feat, batch_num_objs)
def _broadcast_on(graph, typestr, feat_data):
"""Internal function of broadcasting features to all nodes/edges.
Parameters
----------
graph : DGLGraph
The graph
typestr : str
'nodes' or 'edges'
feat_data : tensor
The feature to broadcast. Tensor shape is :math:`(*)` for single graph,
and :math:`(B, *)` for batched graph.
Returns
-------
tensor
The node/edge features tensor with shape :math:`(N, *)`.
"""
_, batch_num_objs_attr, _ = READOUT_ON_ATTRS[typestr]
batch_num_objs = getattr(graph, batch_num_objs_attr)
index = []
for i, num_obj in enumerate(batch_num_objs):
index.extend([i] * num_obj)
ctx = F.context(feat_data)
index = F.copy_to(F.tensor(index), ctx)
return F.gather_row(feat_data, index)
def _topk_on(graph, typestr, feat, k, descending=True, idx=None):
"""Internal function to take graph-wise top-k node/edge features of
field :attr:`feat` in :attr:`graph` ranked by keys at given
index :attr:`idx`. If :attr:`descending` is set to False, return the
k smallest elements instead.
If idx is set to None, the function would return top-k value of all
indices, which is equivalent to calling `th.topk(graph.ndata[feat], dim=0)`
for each single graph of the input batched-graph.
Parameters
---------
graph : DGLGraph
The graph
typestr : str
'nodes' or 'edges'
feat : str
The feature field name.
k : int
The :math:`k` in "top-:math`k`".
descending : bool
Controls whether to return the largest or smallest elements,
defaults to True.
idx : int or None, defaults to None
The key index we sort :attr:`feat` on, if set to None, we sort
the whole :attr:`feat`.
Returns
-------
tuple of tensors:
The first tensor returns top-k features of each single graph of
the input graph:
a tensor with shape :math:`(B, K, D)` would be returned, where
:math:`B` is the batch size of the input graph.
The second tensor returns the top-k indices of each single graph
of the input graph:
a tensor with shape :math:`(B, K)`(:math:`(B, K, D)` if` idx
is set to None) would be returned, where
:math:`B` is the batch size of the input graph.
Notes
-----
If an example has :math:`n` nodes/edges and :math:`n<k`, in the first
returned tensor the :math:`n+1` to :math:`k`th rows would be padded
with all zero; in the second returned tensor, the behavior of :math:`n+1`
to :math:`k`th elements is not defined.
"""
data_attr, batch_num_objs_attr, _ = READOUT_ON_ATTRS[typestr]
data = getattr(graph, data_attr)
if F.ndim(data[feat]) > 2:
raise DGLError('The {} feature `{}` should have dimension less than or'
' equal to 2'.format(typestr, feat))
feat = data[feat]
hidden_size = F.shape(feat)[-1]
batch_num_objs = getattr(graph, batch_num_objs_attr)
batch_size = len(batch_num_objs)
length = max(max(batch_num_objs), k)
fill_val = -float('inf') if descending else float('inf')
feat_ = F.pad_packed_tensor(feat, batch_num_objs, fill_val, l_min=k)
if idx is not None:
keys = F.squeeze(F.slice_axis(feat_, -1, idx, idx+1), -1)
order = F.argsort(keys, -1, descending=descending)
else:
order = F.argsort(feat_, 1, descending=descending)
topk_indices = F.slice_axis(order, 1, 0, k)
# zero padding
feat_ = F.pad_packed_tensor(feat, batch_num_objs, 0, l_min=k)
if idx is not None:
feat_ = F.reshape(feat_, (batch_size * length, -1))
shift = F.repeat(F.arange(0, batch_size) * length, k, -1)
shift = F.copy_to(shift, F.context(feat))
topk_indices_ = F.reshape(topk_indices, (-1,)) + shift
else:
feat_ = F.reshape(feat_, (-1,))
shift = F.repeat(F.arange(0, batch_size), k * hidden_size, -1) * length * hidden_size +\
F.cat([F.arange(0, hidden_size)] * batch_size * k, -1)
shift = F.copy_to(shift, F.context(feat))
topk_indices_ = F.reshape(topk_indices, (-1,)) * hidden_size + shift
return F.reshape(F.gather_row(feat_, topk_indices_), (batch_size, k, -1)),\
topk_indices
def max_nodes(graph, feat):
"""Take elementwise maximum over all the values of node field
:attr:`feat` in :attr:`graph`
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
Returns
-------
tensor
The tensor obtained.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
node features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.ndata['h'] = th.tensor([[1.], [2.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.ndata['h'] = th.tensor([[1.], [2.], [3.]])
Max over node attribute :attr:`h` in a batched graph.
>>> bg = dgl.batch([g1, g2], node_attrs='h')
>>> dgl.max_nodes(bg, 'h')
tensor([[2.], # max(1, 2)
[3.]]) # max(1, 2, 3)
Max over node attribute :attr:`h` in a single graph.
>>> dgl.max_nodes(g1, 'h')
tensor([[2.]])
Notes
-----
Return a stacked tensor with an extra first dimension whose size equals
batch size of the input graph.
The i-th row of the stacked tensor contains the readout result of
the i-th graph in the batched graph. If a graph has no nodes,
a tensor filed with -inf of the same shape is returned at the
corresponding row.
"""
return _max_on(graph, 'nodes', feat)
def max_edges(graph, feat):
"""Take elementwise maximum over all the values of edge field
:attr:`feat` in :attr:`graph`
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
Returns
-------
tensor
The tensor obtained.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
edge features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.add_edges([0, 1], [1, 0])
>>> g1.edata['h'] = th.tensor([[1.], [2.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.add_edges([0, 1, 2], [1, 2, 0])
>>> g2.edata['h'] = th.tensor([[1.], [2.], [3.]])
Max over edge attribute :attr:`h` in a batched graph.
>>> bg = dgl.batch([g1, g2], edge_attrs='h')
>>> dgl.max_edges(bg, 'h')
tensor([[2.], # max(1, 2)
[3.]]) # max(1, 2, 3)
Max over edge attribute :attr:`h` in a single graph.
>>> dgl.max_edges(g1, 'h')
tensor([[2.]])
Notes
-----
Return a stacked tensor with an extra first dimension whose size equals
batch size of the input graph.
The i-th row of the stacked tensor contains the readout result of
the i-th graph in the batched graph. If a graph has no edges,
a tensor filled with -inf of the same shape is returned at the
corresponding row.
"""
return _max_on(graph, 'edges', feat)
def softmax_nodes(graph, feat):
"""Apply batch-wise graph-level softmax over all the values of node field
:attr:`feat` in :attr:`graph`.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
Returns
-------
tensor
The tensor obtained.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
node features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.ndata['h'] = th.tensor([[1., 0.], [2., 0.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.ndata['h'] = th.tensor([[1., 0.], [2., 0.], [3., 0.]])
Softmax over node attribute :attr:`h` in a batched graph.
>>> bg = dgl.batch([g1, g2], node_attrs='h')
>>> dgl.softmax_nodes(bg, 'h')
tensor([[0.2689, 0.5000], # [0.2689, 0.7311] = softmax([1., 2.])
[0.7311, 0.5000], # [0.5000, 0.5000] = softmax([0., 0.])
[0.0900, 0.3333], # [0.0900, 0.2447, 0.6652] = softmax([1., 2., 3.])
[0.2447, 0.3333], # [0.3333, 0.3333, 0.3333] = softmax([0., 0., 0.])
[0.6652, 0.3333]])
Softmax over node attribute :attr:`h` in a single graph.
>>> dgl.softmax_nodes(g1, 'h')
tensor([[0.2689, 0.5000], # [0.2689, 0.7311] = softmax([1., 2.])
[0.7311, 0.5000]]), # [0.5000, 0.5000] = softmax([0., 0.])
Notes
-----
If the input graph has batch size greater then one, the softmax is applied at
each single graph in the batched graph.
"""
return _softmax_on(graph, 'nodes', feat)
def softmax_edges(graph, feat):
"""Apply batch-wise graph-level softmax over all the values of edge field
:attr:`feat` in :attr:`graph`.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
Returns
-------
tensor
The tensor obtained.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
edge features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.add_edges([0, 1], [1, 0])
>>> g1.edata['h'] = th.tensor([[1., 0.], [2., 0.]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.add_edges([0, 1, 2], [1, 2, 0])
>>> g2.edata['h'] = th.tensor([[1., 0.], [2., 0.], [3., 0.]])
Softmax over edge attribute :attr:`h` in a batched graph.
>>> bg = dgl.batch([g1, g2], edge_attrs='h')
>>> dgl.softmax_edges(bg, 'h')
tensor([[0.2689, 0.5000], # [0.2689, 0.7311] = softmax([1., 2.])
[0.7311, 0.5000], # [0.5000, 0.5000] = softmax([0., 0.])
[0.0900, 0.3333], # [0.0900, 0.2447, 0.6652] = softmax([1., 2., 3.])
[0.2447, 0.3333], # [0.3333, 0.3333, 0.3333] = softmax([0., 0., 0.])
[0.6652, 0.3333]])
Softmax over edge attribute :attr:`h` in a single graph.
>>> dgl.softmax_edges(g1, 'h')
tensor([[0.2689, 0.5000], # [0.2689, 0.7311] = softmax([1., 2.])
[0.7311, 0.5000]]), # [0.5000, 0.5000] = softmax([0., 0.])
Notes
-----
If the input graph has batch size greater then one, the softmax is applied at each
example in the batch.
"""
return _softmax_on(graph, 'edges', feat)
def broadcast_nodes(graph, feat_data):
"""Broadcast :attr:`feat_data` to all nodes in :attr:`graph`, and return a
tensor of node features.
Parameters
----------
graph : DGLGraph
The graph.
feat_data : tensor
The feature to broadcast. Tensor shape is :math:`(*)` for single graph, and
:math:`(B, *)` for batched graph.
Returns
-------
tensor
The node features tensor with shape :math:`(N, *)`.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
node features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> bg = dgl.batch([g1, g2])
>>> feat = th.rand(2, 5)
>>> feat
tensor([[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014]])
Broadcast feature to all nodes in the batched graph, feat[i] is broadcast to nodes
in the i-th example in the batch.
>>> dgl.broadcast_nodes(bg, feat)
tensor([[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014]])
Broadcast feature to all nodes in the batched graph.
>>> dgl.broadcast_nodes(g1, feat[0])
tensor([[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.4325, 0.7710, 0.5541, 0.0544, 0.9368]])
Notes
-----
feat[i] is broadcast to the nodes in i-th graph in the batched graph.
"""
return _broadcast_on(graph, 'nodes', feat_data)
def broadcast_edges(graph, feat_data):
"""Broadcast :attr:`feat_data` to all edges in :attr:`graph`, and return a
tensor of edge features.
Parameters
----------
graph : DGLGraph
The graph.
feat_data : tensor
The feature to broadcast. Tensor shape is :math:`(*)` for single
graph, and :math:`(B, *)` for batched graph.
Returns
-------
tensor
The edge features tensor with shape :math:`(E, *)`
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
edge features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(2)
>>> g1.add_edges([0, 1], [1, 0])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(3)
>>> g2.add_edges([0, 1, 2], [1, 2, 0])
>>> bg = dgl.batch([g1, g2])
>>> feat = th.rand(2, 5)
>>> feat
tensor([[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014]])
Broadcast feature to all edges in the batched graph, feat[i] is broadcast to edges
in the i-th example in the batch.
>>> dgl.broadcast_edges(bg, feat)
tensor([[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014],
[0.2721, 0.4629, 0.7269, 0.0724, 0.1014]])
Broadcast feature to all edges in the batched graph.
>>> dgl.broadcast_edges(g1, feat[0])
tensor([[0.4325, 0.7710, 0.5541, 0.0544, 0.9368],
[0.4325, 0.7710, 0.5541, 0.0544, 0.9368]])
Notes
-----
feat[i] is broadcast to the edges in i-th graph in the batched graph.
"""
return _broadcast_on(graph, 'edges', feat_data)
def topk_nodes(graph, feat, k, descending=True, idx=None):
"""Return graph-wise top-k node features of field :attr:`feat` in
:attr:`graph` ranked by keys at given index :attr:`idx`. If :attr:
`descending` is set to False, return the k smallest elements instead.
If idx is set to None, the function would return top-k value of all
indices, which is equivalent to calling
:code:`torch.topk(graph.ndata[feat], dim=0)`
for each example of the input graph.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
k : int
The k in "top-k"
descending : bool
Controls whether to return the largest or smallest elements.
idx : int or None, defaults to None
The index of keys we rank :attr:`feat` on, if set to None, we sort
the whole :attr:`feat`.
Returns
-------
tuple of tensors
The first tensor returns top-k node features of each single graph of
the input graph:
a tensor with shape :math:`(B, K, D)` would be returned, where
:math:`B` is the batch size of the input graph.
The second tensor returns the top-k node indices of each single graph
of the input graph:
a tensor with shape :math:`(B, K)`(:math:`(B, K, D)` if` idx
is set to None) would be returned, where
:math:`B` is the batch size of the input graph.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
node features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(4)
>>> g1.ndata['h'] = th.rand(4, 5)
>>> g1.ndata['h']
tensor([[0.0297, 0.8307, 0.9140, 0.6702, 0.3346],
[0.5901, 0.3030, 0.9280, 0.6893, 0.7997],
[0.0880, 0.6515, 0.4451, 0.7507, 0.5297],
[0.5171, 0.6379, 0.2695, 0.8954, 0.5197]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(5)
>>> g2.ndata['h'] = th.rand(5, 5)
>>> g2.ndata['h']
tensor([[0.3168, 0.3174, 0.5303, 0.0804, 0.3808],
[0.1323, 0.2766, 0.4318, 0.6114, 0.1458],
[0.1752, 0.9105, 0.5692, 0.8489, 0.0539],
[0.1931, 0.4954, 0.3455, 0.3934, 0.0857],
[0.5065, 0.5182, 0.5418, 0.1520, 0.3872]])
Top-k over node attribute :attr:`h` in a batched graph.
>>> bg = dgl.batch([g1, g2], node_attrs='h')
>>> dgl.topk_nodes(bg, 'h', 3)
(tensor([[[0.5901, 0.8307, 0.9280, 0.8954, 0.7997],
[0.5171, 0.6515, 0.9140, 0.7507, 0.5297],
[0.0880, 0.6379, 0.4451, 0.6893, 0.5197]],
[[0.5065, 0.9105, 0.5692, 0.8489, 0.3872],
[0.3168, 0.5182, 0.5418, 0.6114, 0.3808],
[0.1931, 0.4954, 0.5303, 0.3934, 0.1458]]]), tensor([[[1, 0, 1, 3, 1],
[3, 2, 0, 2, 2],
[2, 3, 2, 1, 3]],
[[4, 2, 2, 2, 4],
[0, 4, 4, 1, 0],
[3, 3, 0, 3, 1]]]))
Top-k over node attribute :attr:`h` along index -1 in a batched graph.
(used in SortPooling)
>>> dgl.topk_nodes(bg, 'h', 3, idx=-1)
(tensor([[[0.5901, 0.3030, 0.9280, 0.6893, 0.7997],
[0.0880, 0.6515, 0.4451, 0.7507, 0.5297],
[0.5171, 0.6379, 0.2695, 0.8954, 0.5197]],
[[0.5065, 0.5182, 0.5418, 0.1520, 0.3872],
[0.3168, 0.3174, 0.5303, 0.0804, 0.3808],
[0.1323, 0.2766, 0.4318, 0.6114, 0.1458]]]), tensor([[1, 2, 3],
[4, 0, 1]]))
Top-k over node attribute :attr:`h` in a single graph.
>>> dgl.topk_nodes(g1, 'h', 3)
(tensor([[[0.5901, 0.8307, 0.9280, 0.8954, 0.7997],
[0.5171, 0.6515, 0.9140, 0.7507, 0.5297],
[0.0880, 0.6379, 0.4451, 0.6893, 0.5197]]]), tensor([[[1, 0, 1, 3, 1],
[3, 2, 0, 2, 2],
[2, 3, 2, 1, 3]]]))
Notes
-----
If an example has :math:`n` nodes and :math:`n<k`, in the first
returned tensor the :math:`n+1` to :math:`k`th rows would be padded
with all zero; in the second returned tensor, the behavior of :math:`n+1`
to :math:`k`th elements is not defined.
"""
return _topk_on(graph, 'nodes', feat, k, descending=descending, idx=idx)
def topk_edges(graph, feat, k, descending=True, idx=None):
"""Return graph-wise top-k edge features of field :attr:`feat` in
:attr:`graph` ranked by keys at given index :attr:`idx`. If
:attr:`descending` is set to False, return the k smallest elements
instead.
If idx is set to None, the function would return top-k value of all
indices, which is equivalent to calling
:code:`torch.topk(graph.edata[feat], dim=0)`
for each example of the input graph.
Parameters
----------
graph : DGLGraph
The graph.
feat : str
The feature field.
k : int
The k in "top-k".
descending : bool
Controls whether to return the largest or smallest elements.
idx : int or None, defaults to None
The key index we sort :attr:`feat` on, if set to None, we sort
the whole :attr:`feat`.
Returns
-------
tuple of tensors
The first tensor returns top-k edge features of each single graph of
the input graph:
a tensor with shape :math:`(B, K, D)` would be returned, where
:math:`B` is the batch size of the input graph.
The second tensor returns the top-k edge indices of each single graph
of the input graph:
a tensor with shape :math:`(B, K)`(:math:`(B, K, D)` if` idx
is set to None) would be returned, where
:math:`B` is the batch size of the input graph.
Examples
--------
>>> import dgl
>>> import torch as th
Create two :class:`~dgl.DGLGraph` objects and initialize their
edge features.
>>> g1 = dgl.DGLGraph() # Graph 1
>>> g1.add_nodes(4)
>>> g1.add_edges([0, 1, 2, 3], [1, 2, 3, 0])
>>> g1.edata['h'] = th.rand(4, 5)
>>> g1.edata['h']
tensor([[0.0297, 0.8307, 0.9140, 0.6702, 0.3346],
[0.5901, 0.3030, 0.9280, 0.6893, 0.7997],
[0.0880, 0.6515, 0.4451, 0.7507, 0.5297],
[0.5171, 0.6379, 0.2695, 0.8954, 0.5197]])
>>> g2 = dgl.DGLGraph() # Graph 2
>>> g2.add_nodes(5)
>>> g2.add_edges([0, 1, 2, 3, 4], [1, 2, 3, 4, 0])
>>> g2.edata['h'] = th.rand(5, 5)
>>> g2.edata['h']
tensor([[0.3168, 0.3174, 0.5303, 0.0804, 0.3808],
[0.1323, 0.2766, 0.4318, 0.6114, 0.1458],
[0.1752, 0.9105, 0.5692, 0.8489, 0.0539],
[0.1931, 0.4954, 0.3455, 0.3934, 0.0857],
[0.5065, 0.5182, 0.5418, 0.1520, 0.3872]])
Top-k over edge attribute :attr:`h` in a batched graph.
>>> bg = dgl.batch([g1, g2], edge_attrs='h')
>>> dgl.topk_edges(bg, 'h', 3)
(tensor([[[0.5901, 0.8307, 0.9280, 0.8954, 0.7997],
[0.5171, 0.6515, 0.9140, 0.7507, 0.5297],
[0.0880, 0.6379, 0.4451, 0.6893, 0.5197]],
[[0.5065, 0.9105, 0.5692, 0.8489, 0.3872],
[0.3168, 0.5182, 0.5418, 0.6114, 0.3808],
[0.1931, 0.4954, 0.5303, 0.3934, 0.1458]]]), tensor([[[1, 0, 1, 3, 1],
[3, 2, 0, 2, 2],
[2, 3, 2, 1, 3]],
[[4, 2, 2, 2, 4],
[0, 4, 4, 1, 0],
[3, 3, 0, 3, 1]]]))
Top-k over edge attribute :attr:`h` along index -1 in a batched graph.
(used in SortPooling)
>>> dgl.topk_edges(bg, 'h', 3, idx=-1)
(tensor([[[0.5901, 0.3030, 0.9280, 0.6893, 0.7997],
[0.0880, 0.6515, 0.4451, 0.7507, 0.5297],
[0.5171, 0.6379, 0.2695, 0.8954, 0.5197]],
[[0.5065, 0.5182, 0.5418, 0.1520, 0.3872],
[0.3168, 0.3174, 0.5303, 0.0804, 0.3808],
[0.1323, 0.2766, 0.4318, 0.6114, 0.1458]]]), tensor([[1, 2, 3],
[4, 0, 1]]))
Top-k over edge attribute :attr:`h` in a single graph.
>>> dgl.topk_edges(g1, 'h', 3)
(tensor([[[0.5901, 0.8307, 0.9280, 0.8954, 0.7997],
[0.5171, 0.6515, 0.9140, 0.7507, 0.5297],
[0.0880, 0.6379, 0.4451, 0.6893, 0.5197]]]), tensor([[[1, 0, 1, 3, 1],
[3, 2, 0, 2, 2],
[2, 3, 2, 1, 3]]]))
Notes
-----
If an example has :math:`n` edges and :math:`n<k`, in the first
returned tensor the :math:`n+1` to :math:`k`th rows would be padded
with all zero; in the second returned tensor, the behavior of :math:`n+1`
to :math:`k`th elements is not defined.
"""
return _topk_on(graph, 'edges', feat, k, descending=descending, idx=idx)