pydecode.outside

Example

This examples creates a simple hypergraph with random integer weights, and overlays the outside scores onto the graph for several different weight types.

import pydecode
import pydecode.test.utils
import numpy as np
graph = pydecode.test.utils.simple_hypergraph()
weights = np.random.randint(10, size=(len(graph.edges)))
pydecode.draw(graph, weights)

def show_outside(weights, weight_type):
    inside = pydecode.inside(graph, weights, weight_type=weight_type)
    outside = pydecode.outside(graph, weights, inside, weight_type=weight_type)
    return pydecode.draw(graph, weights, outside)

show_outside(np.array(weights, dtype=np.double), pydecode.LogViterbi)

show_outside(np.array(weights, dtype=np.int32), pydecode.Counting)

show_outside(np.array(weights > 5, dtype=np.int8), pydecode.Boolean)

Invariants

import numpy.testing as test
import pydecode.test.utils as test_utils
graph, weights, weight_type = test_utils.random_setup()

inside = pydecode.inside(graph, weights, weight_type=weight_type)
outside = pydecode.outside(graph, weights, inside, weight_type=weight_type)

Scores in the chart represent the sum of all outside paths.

for vertex in graph.vertices:
    if vertex.id == graph.root.id:
        score = weight_type.Value.one()
    else:
        score = weight_type.Value.zero()
        for path in test_utils.outside_paths(graph, vertex):
            score += test_utils.path_score(path, weights, weight_type)
    test.assert_almost_equal(outside[vertex.id], score.value, 5)