pydecode.best_path

Example

This examples creates a simple hypergraph with random integer weights, and highlights the best path in the hypergraph.

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)

path = pydecode.best_path(graph, weights * 1.)
pydecode.draw(graph, weights, paths=[path])

Invariants

Check that the LogViterbi best path scores at least as high as all other paths.

graph = pydecode.test.utils.random_hypergraph()
weights = np.random.random(len(graph.edges))
path = pydecode.best_path(graph, weights)
match = False
for path2 in pydecode.test.utils.all_paths(graph):
    assert weights.T * path.v >= weights.T * path2.v
    if path == path2:
        match = True
        score = pydecode.test.utils.path_score(path2, weights, pydecode.LogViterbi)
        assert math.fabs(score.value - weights.T * path.v) < 1e-4
assert match

---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)

<ipython-input-10-bda59e0186df> in <module>()
      9         match = True
     10         score = pydecode.test.utils.path_score(path2, weights, pydecode.LogViterbi)
---> 11         assert math.fabs(score.value - weights.T * path.v) < 1e-4
     12 assert match


AssertionError: