structure = np.zeros((3,3))
structure[1,2] = 1
g.add_grid_edges(nodeids, structure=structure, weights=weights, symmetric=False)
# Edges pointing up
structure = np.zeros((3,3))
structure[0,1] = 1
g.add_grid_edges(nodeids, structure=structure, weights=weights+100, symmetric=False)
# Edges pointing down
structure = np.zeros((3,3))
structure[2,1] = 1
g.add_grid_edges(nodeids, structure=structure, weights=weights+200, symmetric=False)
# Source node connected to leftmost non-terminal nodes.
left = nodeids[:, 0]
g.add_grid_tedges(left, np.inf, 0)
# Sink node connected to rightmost non-terminal nodes.
right = nodeids[:, -1]
g.add_grid_tedges(right, 0, np.inf)
return nodeids, g
if __name__ == '__main__':
nodeids, g = create_graph()
plot_graph_2d(g, nodeids.shape)
g.maxflow()
print(g.get_grid_segments(nodeids))
import numpy as np import maxflow from examples_utils import plot_graph_2d # Standard 4-connected grid g = maxflow.Graph[int]() nodeids = g.add_grid_nodes((5, 5)) g.add_grid_edges(nodeids, 1) # Equivalent to # structure = maxflow.vonNeumann_structure(ndim=2, directed=False) # g.add_grid_edges(nodeids, 1, # structure=structure, # symmetric=False) plot_graph_2d(g, nodeids.shape, plot_terminals=False) # 8-connected grid, ignore two nodes g = maxflow.Graph[int]() nodeids = g.add_grid_nodes((5, 5)) structure = np.array([[0, 0, 0], [0, 0, 1], [1, 1, 1]]) # Also structure = maxflow.moore_structure(ndim=2, directed=True) # Nodeid -1 is ignored when adding edges nodeids[1, 1] = -1 nodeids[3, 2] = -1 g.add_grid_edges(nodeids, 1, structure=structure, symmetric=True) plot_graph_2d(g, nodeids.shape, plot_terminals=False) # 24-connected 5x5 neighborhood g = maxflow.Graph[int]() nodeids = g.add_grid_nodes((5, 5))
structure[1, 2] = 1
g.add_grid_edges(nodeids, structure=structure, weights=weights, symmetric=False)
# Edges pointing up
structure = np.zeros((3, 3))
structure[0, 1] = 1
g.add_grid_edges(nodeids, structure=structure, weights=weights+100, symmetric=False)
# Edges pointing down
structure = np.zeros((3, 3))
structure[2, 1] = 1
g.add_grid_edges(nodeids, structure=structure, weights=weights+200, symmetric=False)
# Source node connected to leftmost non-terminal nodes.
left = nodeids[:, 0]
g.add_grid_tedges(left, np.inf, 0)
# Sink node connected to rightmost non-terminal nodes.
right = nodeids[:, -1]
g.add_grid_tedges(right, 0, np.inf)
return nodeids, g
if __name__ == '__main__':
nodeids, g = create_graph()
plot_graph_2d(g, nodeids.shape)
g.maxflow()
print(g.get_grid_segments(nodeids))
