torch_geometric.transforms.LaplacianLambdaMax

class LaplacianLambdaMax(normalization: Optional[str] = None, is_undirected: bool = False)

Bases: BaseTransform

Computes the highest eigenvalue of the graph Laplacian given by torch_geometric.utils.get_laplacian() (functional name: laplacian_lambda_max).

Parameters

• normalization (str, optional) –

  The normalization scheme for the graph Laplacian (default: None):

  1. None: No normalization \(\mathbf{L} = \mathbf{D} - \mathbf{A}\)

  2. "sym": Symmetric normalization \(\mathbf{L} = \mathbf{I} - \mathbf{D}^{-1/2} \mathbf{A} \mathbf{D}^{-1/2}\)

  3. "rw": Random-walk normalization \(\mathbf{L} = \mathbf{I} - \mathbf{D}^{-1} \mathbf{A}\)

• is_undirected (bool, optional) – If set to True, this transform expects undirected graphs as input, and can hence speed up the computation of the largest eigenvalue. (default: False)