grakel.ShortestPathAttr

class grakel.ShortestPathAttr(n_jobs=None, normalize=False, verbose=False, algorithm_type='auto', metric=<function dot>)[source][source]

The shortest path kernel for attributes.

The Graph labels are considered as attributes. The computational efficiency is decreased to \(O(|V|^4)\) See [BK05].

Parameters
algorithm_typestr, default={“dijkstra”, “floyd_warshall”, “auto”}

Apply the dijkstra or floyd_warshall algorithm for calculating shortest path, or chose automatically (“auto”) based on the current graph format (“auto”).

metricfunction, default=:math:f(x,y)=sum_{i}x_{i}*y_{i},

The metric applied between attributes of the graph labels. The user must provide a metric based on the format of the provided labels (considered as attributes).

Attributes
Xlist

A list of tuples, consisting of shortest path matrices and their feature vectors.

Methods

diagonal(self)

Calculate the kernel matrix diagonal of the fit/transformed data.

fit(self, X[, y])

Fit a dataset, for a transformer.

fit_transform(self, X)

Fit and transform, on the same dataset.

get_params(self[, deep])

Get parameters for this estimator.

initialize(self)

Initialize all transformer arguments, needing initialization.

pairwise_operation(self, x, y)

Calculate shortests paths on attributes.

parse_input(self, X)

Parse and create features for the shortest_path kernel.

set_params(self, \*\*params)

Call the parent method.

transform(self, X)

Calculate the kernel matrix, between given and fitted dataset.

Initialise a shortest_path_attr kernel.

Attributes
X

Methods

diagonal(self)

Calculate the kernel matrix diagonal of the fit/transformed data.

fit(self, X[, y])

Fit a dataset, for a transformer.

fit_transform(self, X)

Fit and transform, on the same dataset.

get_params(self[, deep])

Get parameters for this estimator.

initialize(self)

Initialize all transformer arguments, needing initialization.

pairwise_operation(self, x, y)

Calculate shortests paths on attributes.

parse_input(self, X)

Parse and create features for the shortest_path kernel.

set_params(self, \*\*params)

Call the parent method.

transform(self, X)

Calculate the kernel matrix, between given and fitted dataset.

__init__(self, n_jobs=None, normalize=False, verbose=False, algorithm_type='auto', metric=<function dot at 0x7f18a56f6840>)[source][source]

Initialise a shortest_path_attr kernel.

diagonal(self)[source]

Calculate the kernel matrix diagonal of the fit/transformed data.

Parameters
None.
Returns
X_diagnp.array

The diagonal of the kernel matrix between the fitted data. This consists of each element calculated with itself.

Y_diagnp.array

The diagonal of the kernel matrix, of the transform. This consists of each element calculated with itself.

fit(self, X, y=None)[source]

Fit a dataset, for a transformer.

Parameters
Xiterable

Each element must be an iterable with at most three features and at least one. The first that is obligatory is a valid graph structure (adjacency matrix or edge_dictionary) while the second is node_labels and the third edge_labels (that fitting the given graph format). The train samples.

yNone

There is no need of a target in a transformer, yet the pipeline API requires this parameter.

Returns
selfobject
Returns self.
fit_transform(self, X)[source]

Fit and transform, on the same dataset.

Parameters
Xiterable

Each element must be an iterable with at most three features and at least one. The first that is obligatory is a valid graph structure (adjacency matrix or edge_dictionary) while the second is node_labels and the third edge_labels (that fitting the given graph format). If None the kernel matrix is calculated upon fit data. The test samples.

yNone

There is no need of a target in a transformer, yet the pipeline API requires this parameter.

Returns
Knumpy array, shape = [n_targets, n_input_graphs]

corresponding to the kernel matrix, a calculation between all pairs of graphs between target an features

get_params(self, deep=True)[source]

Get parameters for this estimator.

Parameters
deepbool, default=True

If True, will return the parameters for this estimator and contained subobjects that are estimators.

Returns
paramsmapping of string to any

Parameter names mapped to their values.

initialize(self)[source][source]

Initialize all transformer arguments, needing initialization.

pairwise_operation(self, x, y)[source][source]

Calculate shortests paths on attributes.

Parameters
x, ytuple

Tuples of shortest path matrices and their attribute dictionaries.

Returns
kernelnumber

The kernel value.

parse_input(self, X)[source][source]

Parse and create features for the shortest_path kernel.

Parameters
Xiterable

For the input to pass the test, we must have: Each element must be an iterable with at most three features and at least one. The first that is obligatory is a valid graph structure (adjacency matrix or edge_dictionary) while the second is node_labels and the third edge_labels (that correspond to the given graph format). A valid input also consists of graph type objects.

Returns
sp_attr_tuplist

A list of tuples of shortest path matrices and tehir attributes.

set_params(self, **params)[source]

Call the parent method.

transform(self, X)[source]

Calculate the kernel matrix, between given and fitted dataset.

Parameters
Xiterable

Each element must be an iterable with at most three features and at least one. The first that is obligatory is a valid graph structure (adjacency matrix or edge_dictionary) while the second is node_labels and the third edge_labels (that fitting the given graph format). If None the kernel matrix is calculated upon fit data. The test samples.

Returns
Knumpy array, shape = [n_targets, n_input_graphs]

corresponding to the kernel matrix, a calculation between all pairs of graphs between target an features

Bibliography

BK05

Karsten M. Borgwardt and Hans-Peter Kriegel. Shortest-path kernels on graphs. In Proceedings of the 5th International Conference on Data Mining, 74–81. 2005.