LazyFeature๏
- class dgl.dataloading.base.LazyFeature(name=None, id_=None)[source]๏
Bases:
object
Placeholder for feature prefetching.
One can assign this object to
ndata
oredata
of the graphs returned by various samplersโsample
method. When DGLโs dataloader receives the subgraphs returned by the sampler, it will automatically look up all thendata
andedata
whose data is a LazyFeature, replacing them with the actual data of the corresponding nodes/edges from the original graph instead. In particular, for a subgraph returned by the sampler has a LazyFeature with namek
insubgraph.ndata[key]
:subgraph.ndata[key] = LazyFeature(k)
Assuming that
graph
is the original graph, DGLโs dataloader will performsubgraph.ndata[key] = graph.ndata[k][subgraph.ndata[dgl.NID]]
DGL dataloader performs similar replacement for
edata
. For heterogeneous graphs, the replacement is:subgraph.nodes[ntype].data[key] = graph.nodes[ntype].data[k][ subgraph.nodes[ntype].data[dgl.NID]]
For MFGsโ
srcdata
(and similarlydstdata
), the replacement ismfg.srcdata[key] = graph.ndata[k][mfg.srcdata[dgl.NID]]
- Parameters:
name (str) โ The name of the data in the original graph.
id (Tensor, optional) โ The ID tensor.