# Drawing#

Tools to visualize topologies of D-Wave QPUs and weighted graph problems on them.

## Chimera Graph Functions#

Tools to visualize Chimera lattices and weighted graph problems on them.

 chimera_layout(G[, scale, center, dim]) Positions the nodes of graph G in a Chimera layout. chimera_node_placer_2d(m, n, t[, scale, ...]) Generates a function that converts Chimera indices to x- and y-coordinates for a plot. draw_chimera(G, **kwargs) Draws graph G in a Chimera layout. draw_chimera_embedding(G, *args, **kwargs) Draws an embedding onto the Chimera graph G. draw_chimera_yield(G, **kwargs) Draws graph G with highlighted faults.

### Example#

This example uses the chimera_layout() function to show the positions of nodes of a simple 5-node NetworkX graph in a Chimera lattice. It then uses the chimera_graph() and draw_chimera() functions to display those positions on a Chimera unit cell.

>>> import networkx as nx
>>> import dwave_networkx as dnx
>>> import matplotlib.pyplot as plt
>>> H = nx.Graph()
>>> H.add_nodes_from([0, 4, 5, 6, 7])
>>> H.add_edges_from([(0, 4), (0, 5), (0, 6), (0, 7)])
>>> pos=dnx.chimera_layout(H)
>>> pos
{0: array([ 0. , -0.5]),
4: array([ 0.5,  0. ]),
5: array([ 0.5 , -0.25]),
6: array([ 0.5 , -0.75]),
7: array([ 0.5, -1. ])}
>>> # Show graph H on a Chimera unit cell
>>> f, axes = plt.subplots(1, 1)
>>> G=dnx.chimera_graph(1, 1, 4)  # Draw a Chimera unit cell
>>> dnx.draw_chimera(G, node_color='r', ax=axes)
>>> dnx.draw_chimera(H, node_color='b', node_shape='*', style='dashed', edge_color='b', width=3, ax=axes)
>>> plt.show()
>>> # matplotlib commands to add labels to graphic not shown


## Pegasus Graph Functions#

Tools to visualize Pegasus lattices and weighted graph problems on them.

 draw_pegasus(G[, crosses]) Draws graph G in a Pegasus topology. draw_pegasus_embedding(G, *args, **kwargs) Draws an embedding onto Pegasus graph G. draw_pegasus_yield(G, **kwargs) Draws graph G with highlighted faults. pegasus_layout(G[, scale, center, dim, crosses]) Positions the nodes of graph G in a Pegasus topology. pegasus_node_placer_2d(G[, scale, center, ...]) Generates a function to convert Pegasus indices to plottable coordinates.

### Example#

This example uses the draw_pegasus() function to show the positions of nodes of a simple 5-node graph on a small Pegasus lattice.

>>> import dwave_networkx as dnx
>>> import matplotlib.pyplot as plt
>>> G = dnx.pegasus_graph(2)
>>> H = dnx.pegasus_graph(2, node_list=[4, 40, 41, 42, 43],
edge_list=[(4, 40), (4, 41), (4, 42), (4, 43)])
>>> # Show graph H on a small Pegasus lattice
>>> f, axes = plt.subplots(1, 1)
>>> dnx.draw_pegasus(G, with_labels=True, crosses=True, node_color="Yellow", ax=axes)
>>> dnx.draw_pegasus(H, crosses=True, node_color='b', style='dashed',
edge_color='b', width=3, ax=axes)
>>> plt.show()


## Zephyr Graph Functions#

Tools to visualize Zephyr lattices and weighted graph problems on them.

 draw_zephyr(G, **kwargs) Draws graph G in a Zephyr topology. draw_zephyr_embedding(G, *args, **kwargs) Draws an embedding onto a Zephyr graph G. draw_zephyr_yield(G, **kwargs) Draws graph G with highlighted faults, according to the Zephyr layout. zephyr_layout(G[, scale, center, dim]) Positions the nodes of graph G in a Zephyr topology. zephyr_node_placer_2d(G[, scale, center, dim]) Generates a function to convert Zephyr indices to plottable coordinates.

### Example#

This example uses the draw_zephyr_embedding() function to show the positions of a five-node clique on a small Zephyr graph.

>>> import dwave_networkx as dnx
>>> import matplotlib.pyplot as plt
>>> import networkx as nx
...
>>> G = dnx.zephyr_graph(1)
>>> embedding = {"N1": [13, 44], "N2": [11], "N3": [41], "N4": [40], "N5": [9, 37]}
...
>>> plt.ion()
>>> dnx.draw_zephyr_embedding(G, embedding, show_labels=True)