Source code for networkx.drawing.nx_pylab

"""
**********
Matplotlib
**********

Draw networks with matplotlib.

See Also
--------

matplotlib:     http://matplotlib.org/

pygraphviz:     http://pygraphviz.github.io/

"""
from numbers import Number
import networkx as nx
from networkx.drawing.layout import shell_layout, \
    circular_layout, kamada_kawai_layout, spectral_layout, \
    spring_layout, random_layout, planar_layout

__all__ = ['draw',
           'draw_networkx',
           'draw_networkx_nodes',
           'draw_networkx_edges',
           'draw_networkx_labels',
           'draw_networkx_edge_labels',
           'draw_circular',
           'draw_kamada_kawai',
           'draw_random',
           'draw_spectral',
           'draw_spring',
           'draw_planar',
           'draw_shell']


[docs]def draw(G, pos=None, ax=None, **kwds): """Draw the graph G with Matplotlib. Draw the graph as a simple representation with no node labels or edge labels and using the full Matplotlib figure area and no axis labels by default. See draw_networkx() for more full-featured drawing that allows title, axis labels etc. Parameters ---------- G : graph A networkx graph pos : dictionary, optional A dictionary with nodes as keys and positions as values. If not specified a spring layout positioning will be computed. See :py:mod:`networkx.drawing.layout` for functions that compute node positions. ax : Matplotlib Axes object, optional Draw the graph in specified Matplotlib axes. kwds : optional keywords See networkx.draw_networkx() for a description of optional keywords. Examples -------- >>> G = nx.dodecahedral_graph() >>> nx.draw(G) >>> nx.draw(G, pos=nx.spring_layout(G)) # use spring layout See Also -------- draw_networkx() draw_networkx_nodes() draw_networkx_edges() draw_networkx_labels() draw_networkx_edge_labels() Notes ----- This function has the same name as pylab.draw and pyplot.draw so beware when using `from networkx import *` since you might overwrite the pylab.draw function. With pyplot use >>> import matplotlib.pyplot as plt >>> import networkx as nx >>> G = nx.dodecahedral_graph() >>> nx.draw(G) # networkx draw() >>> plt.draw() # pyplot draw() Also see the NetworkX drawing examples at https://networkx.github.io/documentation/latest/auto_examples/index.html """ try: import matplotlib.pyplot as plt except ImportError: raise ImportError("Matplotlib required for draw()") except RuntimeError: print("Matplotlib unable to open display") raise if ax is None: cf = plt.gcf() else: cf = ax.get_figure() cf.set_facecolor('w') if ax is None: if cf._axstack() is None: ax = cf.add_axes((0, 0, 1, 1)) else: ax = cf.gca() if 'with_labels' not in kwds: kwds['with_labels'] = 'labels' in kwds draw_networkx(G, pos=pos, ax=ax, **kwds) ax.set_axis_off() plt.draw_if_interactive() return
[docs]def draw_networkx(G, pos=None, arrows=True, with_labels=True, **kwds): """Draw the graph G using Matplotlib. Draw the graph with Matplotlib with options for node positions, labeling, titles, and many other drawing features. See draw() for simple drawing without labels or axes. Parameters ---------- G : graph A networkx graph pos : dictionary, optional A dictionary with nodes as keys and positions as values. If not specified a spring layout positioning will be computed. See :py:mod:`networkx.drawing.layout` for functions that compute node positions. arrows : bool, optional (default=True) For directed graphs, if True draw arrowheads. Note: Arrows will be the same color as edges. arrowstyle : str, optional (default='-|>') For directed graphs, choose the style of the arrowsheads. See :py:class: `matplotlib.patches.ArrowStyle` for more options. arrowsize : int, optional (default=10) For directed graphs, choose the size of the arrow head head's length and width. See :py:class: `matplotlib.patches.FancyArrowPatch` for attribute `mutation_scale` for more info. with_labels : bool, optional (default=True) Set to True to draw labels on the nodes. ax : Matplotlib Axes object, optional Draw the graph in the specified Matplotlib axes. nodelist : list, optional (default G.nodes()) Draw only specified nodes edgelist : list, optional (default=G.edges()) Draw only specified edges node_size : scalar or array, optional (default=300) Size of nodes. If an array is specified it must be the same length as nodelist. node_color : color or array of colors (default='#1f78b4') Node color. Can be a single color or a sequence of colors with the same length as nodelist. Color can be string, or rgb (or rgba) tuple of floats from 0-1. If numeric values are specified they will be mapped to colors using the cmap and vmin,vmax parameters. See matplotlib.scatter for more details. node_shape : string, optional (default='o') The shape of the node. Specification is as matplotlib.scatter marker, one of 'so^>v<dph8'. alpha : float, optional (default=None) The node and edge transparency cmap : Matplotlib colormap, optional (default=None) Colormap for mapping intensities of nodes vmin,vmax : float, optional (default=None) Minimum and maximum for node colormap scaling linewidths : [None | scalar | sequence] Line width of symbol border (default =1.0) width : float, optional (default=1.0) Line width of edges edge_color : color or array of colors (default='k') Edge color. Can be a single color or a sequence of colors with the same length as edgelist. Color can be string, or rgb (or rgba) tuple of floats from 0-1. If numeric values are specified they will be mapped to colors using the edge_cmap and edge_vmin,edge_vmax parameters. edge_cmap : Matplotlib colormap, optional (default=None) Colormap for mapping intensities of edges edge_vmin,edge_vmax : floats, optional (default=None) Minimum and maximum for edge colormap scaling style : string, optional (default='solid') Edge line style (solid|dashed|dotted,dashdot) labels : dictionary, optional (default=None) Node labels in a dictionary keyed by node of text labels font_size : int, optional (default=12) Font size for text labels font_color : string, optional (default='k' black) Font color string font_weight : string, optional (default='normal') Font weight font_family : string, optional (default='sans-serif') Font family label : string, optional Label for graph legend Notes ----- For directed graphs, arrows are drawn at the head end. Arrows can be turned off with keyword arrows=False. Examples -------- >>> G = nx.dodecahedral_graph() >>> nx.draw(G) >>> nx.draw(G, pos=nx.spring_layout(G)) # use spring layout >>> import matplotlib.pyplot as plt >>> limits = plt.axis('off') # turn of axis Also see the NetworkX drawing examples at https://networkx.github.io/documentation/latest/auto_examples/index.html See Also -------- draw() draw_networkx_nodes() draw_networkx_edges() draw_networkx_labels() draw_networkx_edge_labels() """ try: import matplotlib.pyplot as plt except ImportError: raise ImportError("Matplotlib required for draw()") except RuntimeError: print("Matplotlib unable to open display") raise if pos is None: pos = nx.drawing.spring_layout(G) # default to spring layout node_collection = draw_networkx_nodes(G, pos, **kwds) edge_collection = draw_networkx_edges(G, pos, arrows=arrows, **kwds) if with_labels: draw_networkx_labels(G, pos, **kwds) plt.draw_if_interactive()
[docs]def draw_networkx_nodes(G, pos, nodelist=None, node_size=300, node_color='#1f78b4', node_shape='o', alpha=None, cmap=None, vmin=None, vmax=None, ax=None, linewidths=None, edgecolors=None, label=None, **kwds): """Draw the nodes of the graph G. This draws only the nodes of the graph G. Parameters ---------- G : graph A networkx graph pos : dictionary A dictionary with nodes as keys and positions as values. Positions should be sequences of length 2. ax : Matplotlib Axes object, optional Draw the graph in the specified Matplotlib axes. nodelist : list, optional Draw only specified nodes (default G.nodes()) node_size : scalar or array Size of nodes (default=300). If an array is specified it must be the same length as nodelist. node_color : color or array of colors (default='#1f78b4') Node color. Can be a single color or a sequence of colors with the same length as nodelist. Color can be string, or rgb (or rgba) tuple of floats from 0-1. If numeric values are specified they will be mapped to colors using the cmap and vmin,vmax parameters. See matplotlib.scatter for more details. node_shape : string The shape of the node. Specification is as matplotlib.scatter marker, one of 'so^>v<dph8' (default='o'). alpha : float or array of floats The node transparency. This can be a single alpha value (default=None), in which case it will be applied to all the nodes of color. Otherwise, if it is an array, the elements of alpha will be applied to the colors in order (cycling through alpha multiple times if necessary). cmap : Matplotlib colormap Colormap for mapping intensities of nodes (default=None) vmin,vmax : floats Minimum and maximum for node colormap scaling (default=None) linewidths : [None | scalar | sequence] Line width of symbol border (default =1.0) edgecolors : [None | scalar | sequence] Colors of node borders (default = node_color) label : [None| string] Label for legend min_source_margin : int, optional (default=0) The minimum margin (gap) at the begining of the edge at the source. min_target_margin : int, optional (default=0) The minimum margin (gap) at the end of the edge at the target. Returns ------- matplotlib.collections.PathCollection `PathCollection` of the nodes. Examples -------- >>> G = nx.dodecahedral_graph() >>> nodes = nx.draw_networkx_nodes(G, pos=nx.spring_layout(G)) Also see the NetworkX drawing examples at https://networkx.github.io/documentation/latest/auto_examples/index.html See Also -------- draw() draw_networkx() draw_networkx_edges() draw_networkx_labels() draw_networkx_edge_labels() """ from collections.abc import Iterable try: import matplotlib.pyplot as plt import numpy as np except ImportError: raise ImportError("Matplotlib required for draw()") except RuntimeError: print("Matplotlib unable to open display") raise if ax is None: ax = plt.gca() if nodelist is None: nodelist = list(G) if len(nodelist) == 0: # empty nodelist, no drawing return try: xy = np.asarray([pos[v] for v in nodelist]) except KeyError as e: raise nx.NetworkXError('Node %s has no position.' % e) except ValueError: raise nx.NetworkXError('Bad value in node positions.') if isinstance(alpha, Iterable): node_color = apply_alpha(node_color, alpha, nodelist, cmap, vmin, vmax) alpha = None node_collection = ax.scatter(xy[:, 0], xy[:, 1], s=node_size, c=node_color, marker=node_shape, cmap=cmap, vmin=vmin, vmax=vmax, alpha=alpha, linewidths=linewidths, edgecolors=edgecolors, label=label) ax.tick_params( axis='both', which='both', bottom=False, left=False, labelbottom=False, labelleft=False) node_collection.set_zorder(2) return node_collection
[docs]def draw_networkx_edges(G, pos, edgelist=None, width=1.0, edge_color='k', style='solid', alpha=None, arrowstyle='-|>', arrowsize=10, edge_cmap=None, edge_vmin=None, edge_vmax=None, ax=None, arrows=True, label=None, node_size=300, nodelist=None, node_shape="o", connectionstyle=None, min_source_margin=0, min_target_margin=0, **kwds): """Draw the edges of the graph G. This draws only the edges of the graph G. Parameters ---------- G : graph A networkx graph pos : dictionary A dictionary with nodes as keys and positions as values. Positions should be sequences of length 2. edgelist : collection of edge tuples Draw only specified edges(default=G.edges()) width : float, or array of floats Line width of edges (default=1.0) edge_color : color or array of colors (default='k') Edge color. Can be a single color or a sequence of colors with the same length as edgelist. Color can be string, or rgb (or rgba) tuple of floats from 0-1. If numeric values are specified they will be mapped to colors using the edge_cmap and edge_vmin,edge_vmax parameters. style : string Edge line style (default='solid') (solid|dashed|dotted,dashdot) alpha : float The edge transparency (default=None) edge_ cmap : Matplotlib colormap Colormap for mapping intensities of edges (default=None) edge_vmin,edge_vmax : floats Minimum and maximum for edge colormap scaling (default=None) ax : Matplotlib Axes object, optional Draw the graph in the specified Matplotlib axes. arrows : bool, optional (default=True) For directed graphs, if True draw arrowheads. Note: Arrows will be the same color as edges. arrowstyle : str, optional (default='-|>') For directed graphs, choose the style of the arrow heads. See :py:class: `matplotlib.patches.ArrowStyle` for more options. arrowsize : int, optional (default=10) For directed graphs, choose the size of the arrow head head's length and width. See :py:class: `matplotlib.patches.FancyArrowPatch` for attribute `mutation_scale` for more info. connectionstyle : str, optional (default=None) Pass the connectionstyle parameter to create curved arc of rounding radius rad. For example, connectionstyle='arc3,rad=0.2'. See :py:class: `matplotlib.patches.ConnectionStyle` and :py:class: `matplotlib.patches.FancyArrowPatch` for more info. label : [None| string] Label for legend min_source_margin : int, optional (default=0) The minimum margin (gap) at the begining of the edge at the source. min_target_margin : int, optional (default=0) The minimum margin (gap) at the end of the edge at the target. Returns ------- matplotlib.collection.LineCollection `LineCollection` of the edges list of matplotlib.patches.FancyArrowPatch `FancyArrowPatch` instances of the directed edges Depending whether the drawing includes arrows or not. Notes ----- For directed graphs, arrows are drawn at the head end. Arrows can be turned off with keyword arrows=False. Be sure to include `node_size` as a keyword argument; arrows are drawn considering the size of nodes. Examples -------- >>> G = nx.dodecahedral_graph() >>> edges = nx.draw_networkx_edges(G, pos=nx.spring_layout(G)) >>> G = nx.DiGraph() >>> G.add_edges_from([(1, 2), (1, 3), (2, 3)]) >>> arcs = nx.draw_networkx_edges(G, pos=nx.spring_layout(G)) >>> alphas = [0.3, 0.4, 0.5] >>> for i, arc in enumerate(arcs): # change alpha values of arcs ... arc.set_alpha(alphas[i]) Also see the NetworkX drawing examples at https://networkx.github.io/documentation/latest/auto_examples/index.html See Also -------- draw() draw_networkx() draw_networkx_nodes() draw_networkx_labels() draw_networkx_edge_labels() """ try: import matplotlib import matplotlib.pyplot as plt from matplotlib.colors import colorConverter, Colormap, Normalize from matplotlib.collections import LineCollection from matplotlib.patches import FancyArrowPatch import numpy as np except ImportError: raise ImportError("Matplotlib required for draw()") except RuntimeError: print("Matplotlib unable to open display") raise if ax is None: ax = plt.gca() if edgelist is None: edgelist = list(G.edges()) if not edgelist or len(edgelist) == 0: # no edges! return None if nodelist is None: nodelist = list(G.nodes()) # FancyArrowPatch handles color=None different from LineCollection if edge_color is None: edge_color = 'k' # set edge positions edge_pos = np.asarray([(pos[e[0]], pos[e[1]]) for e in edgelist]) # Check if edge_color is an array of floats and map to edge_cmap. # This is the only case handled differently from matplotlib if np.iterable(edge_color) and (len(edge_color) == len(edge_pos)) \ and np.alltrue([isinstance(c, Number) for c in edge_color]): if edge_cmap is not None: assert(isinstance(edge_cmap, Colormap)) else: edge_cmap = plt.get_cmap() if edge_vmin is None: edge_vmin = min(edge_color) if edge_vmax is None: edge_vmax = max(edge_color) color_normal = Normalize(vmin=edge_vmin, vmax=edge_vmax) edge_color = [edge_cmap(color_normal(e)) for e in edge_color] if (not G.is_directed() or not arrows): edge_collection = LineCollection(edge_pos, colors=edge_color, linewidths=width, antialiaseds=(1,), linestyle=style, transOffset=ax.transData, alpha=alpha ) edge_collection.set_cmap(edge_cmap) edge_collection.set_clim(edge_vmin, edge_vmax) edge_collection.set_zorder(1) # edges go behind nodes edge_collection.set_label(label) ax.add_collection(edge_collection) return edge_collection arrow_collection = None if G.is_directed() and arrows: # Note: Waiting for someone to implement arrow to intersection with # marker. Meanwhile, this works well for polygons with more than 4 # sides and circle. def to_marker_edge(marker_size, marker): if marker in "s^>v<d": # `large` markers need extra space return np.sqrt(2 * marker_size) / 2 else: return np.sqrt(marker_size) / 2 # Draw arrows with `matplotlib.patches.FancyarrowPatch` arrow_collection = [] mutation_scale = arrowsize # scale factor of arrow head # FancyArrowPatch doesn't handle color strings arrow_colors = colorConverter.to_rgba_array(edge_color, alpha) for i, (src, dst) in enumerate(edge_pos): x1, y1 = src x2, y2 = dst shrink_source = 0 # space from source to tail shrink_target = 0 # space from head to target if np.iterable(node_size): # many node sizes src_node, dst_node = edgelist[i][:2] index_node = nodelist.index(dst_node) marker_size = node_size[index_node] shrink_target = to_marker_edge(marker_size, node_shape) else: shrink_target = to_marker_edge(node_size, node_shape) if shrink_source < min_source_margin: shrink_source = min_source_margin if shrink_target < min_target_margin: shrink_target = min_target_margin if len(arrow_colors) == len(edge_pos): arrow_color = arrow_colors[i] elif len(arrow_colors) == 1: arrow_color = arrow_colors[0] else: # Cycle through colors arrow_color = arrow_colors[i % len(arrow_colors)] if np.iterable(width): if len(width) == len(edge_pos): line_width = width[i] else: line_width = width[i % len(width)] else: line_width = width arrow = FancyArrowPatch((x1, y1), (x2, y2), arrowstyle=arrowstyle, shrinkA=shrink_source, shrinkB=shrink_target, mutation_scale=mutation_scale, color=arrow_color, linewidth=line_width, connectionstyle=connectionstyle, zorder=1) # arrows go behind nodes # There seems to be a bug in matplotlib to make collections of # FancyArrowPatch instances. Until fixed, the patches are added # individually to the axes instance. arrow_collection.append(arrow) ax.add_patch(arrow) # update view minx = np.amin(np.ravel(edge_pos[:, :, 0])) maxx = np.amax(np.ravel(edge_pos[:, :, 0])) miny = np.amin(np.ravel(edge_pos[:, :, 1])) maxy = np.amax(np.ravel(edge_pos[:, :, 1])) w = maxx - minx h = maxy - miny padx, pady = 0.05 * w, 0.05 * h corners = (minx - padx, miny - pady), (maxx + padx, maxy + pady) ax.update_datalim(corners) ax.autoscale_view() ax.tick_params( axis='both', which='both', bottom=False, left=False, labelbottom=False, labelleft=False) return arrow_collection
[docs]def draw_networkx_labels(G, pos, labels=None, font_size=12, font_color='k', font_family='sans-serif', font_weight='normal', alpha=None, bbox=None, ax=None, **kwds): """Draw node labels on the graph G. Parameters ---------- G : graph A networkx graph pos : dictionary A dictionary with nodes as keys and positions as values. Positions should be sequences of length 2. labels : dictionary, optional (default=None) Node labels in a dictionary keyed by node of text labels Node-keys in labels should appear as keys in `pos`. If needed use: `{n:lab for n,lab in labels.items() if n in pos}` font_size : int Font size for text labels (default=12) font_color : string Font color string (default='k' black) font_family : string Font family (default='sans-serif') font_weight : string Font weight (default='normal') alpha : float or None The text transparency (default=None) ax : Matplotlib Axes object, optional Draw the graph in the specified Matplotlib axes. Returns ------- dict `dict` of labels keyed on the nodes Examples -------- >>> G = nx.dodecahedral_graph() >>> labels = nx.draw_networkx_labels(G, pos=nx.spring_layout(G)) Also see the NetworkX drawing examples at https://networkx.github.io/documentation/latest/auto_examples/index.html See Also -------- draw() draw_networkx() draw_networkx_nodes() draw_networkx_edges() draw_networkx_edge_labels() """ try: import matplotlib.pyplot as plt except ImportError: raise ImportError("Matplotlib required for draw()") except RuntimeError: print("Matplotlib unable to open display") raise if ax is None: ax = plt.gca() if labels is None: labels = dict((n, n) for n in G.nodes()) # set optional alignment horizontalalignment = kwds.get('horizontalalignment', 'center') verticalalignment = kwds.get('verticalalignment', 'center') text_items = {} # there is no text collection so we'll fake one for n, label in labels.items(): (x, y) = pos[n] if not isinstance(label, str): label = str(label) # this makes "1" and 1 labeled the same t = ax.text(x, y, label, size=font_size, color=font_color, family=font_family, weight=font_weight, alpha=alpha, horizontalalignment=horizontalalignment, verticalalignment=verticalalignment, transform=ax.transData, bbox=bbox, clip_on=True, ) text_items[n] = t ax.tick_params( axis='both', which='both', bottom=False, left=False, labelbottom=False, labelleft=False) return text_items
[docs]def draw_networkx_edge_labels(G, pos, edge_labels=None, label_pos=0.5, font_size=10, font_color='k', font_family='sans-serif', font_weight='normal', alpha=None, bbox=None, ax=None, rotate=True, **kwds): """Draw edge labels. Parameters ---------- G : graph A networkx graph pos : dictionary A dictionary with nodes as keys and positions as values. Positions should be sequences of length 2. ax : Matplotlib Axes object, optional Draw the graph in the specified Matplotlib axes. alpha : float or None The text transparency (default=None) edge_labels : dictionary Edge labels in a dictionary keyed by edge two-tuple of text labels (default=None). Only labels for the keys in the dictionary are drawn. label_pos : float Position of edge label along edge (0=head, 0.5=center, 1=tail) font_size : int Font size for text labels (default=12) font_color : string Font color string (default='k' black) font_weight : string Font weight (default='normal') font_family : string Font family (default='sans-serif') bbox : Matplotlib bbox Specify text box shape and colors. clip_on : bool Turn on clipping at axis boundaries (default=True) Returns ------- dict `dict` of labels keyed on the edges Examples -------- >>> G = nx.dodecahedral_graph() >>> edge_labels = nx.draw_networkx_edge_labels(G, pos=nx.spring_layout(G)) Also see the NetworkX drawing examples at https://networkx.github.io/documentation/latest/auto_examples/index.html See Also -------- draw() draw_networkx() draw_networkx_nodes() draw_networkx_edges() draw_networkx_labels() """ try: import matplotlib.pyplot as plt import numpy as np except ImportError: raise ImportError("Matplotlib required for draw()") except RuntimeError: print("Matplotlib unable to open display") raise if ax is None: ax = plt.gca() if edge_labels is None: labels = {(u, v): d for u, v, d in G.edges(data=True)} else: labels = edge_labels text_items = {} for (n1, n2), label in labels.items(): (x1, y1) = pos[n1] (x2, y2) = pos[n2] (x, y) = (x1 * label_pos + x2 * (1.0 - label_pos), y1 * label_pos + y2 * (1.0 - label_pos)) if rotate: # in degrees angle = np.arctan2(y2 - y1, x2 - x1) / (2.0 * np.pi) * 360 # make label orientation "right-side-up" if angle > 90: angle -= 180 if angle < - 90: angle += 180 # transform data coordinate angle to screen coordinate angle xy = np.array((x, y)) trans_angle = ax.transData.transform_angles(np.array((angle,)), xy.reshape((1, 2)))[0] else: trans_angle = 0.0 # use default box of white with white border if bbox is None: bbox = dict(boxstyle='round', ec=(1.0, 1.0, 1.0), fc=(1.0, 1.0, 1.0), ) if not isinstance(label, str): label = str(label) # this makes "1" and 1 labeled the same # set optional alignment horizontalalignment = kwds.get('horizontalalignment', 'center') verticalalignment = kwds.get('verticalalignment', 'center') t = ax.text(x, y, label, size=font_size, color=font_color, family=font_family, weight=font_weight, alpha=alpha, horizontalalignment=horizontalalignment, verticalalignment=verticalalignment, rotation=trans_angle, transform=ax.transData, bbox=bbox, zorder=1, clip_on=True, ) text_items[(n1, n2)] = t ax.tick_params( axis='both', which='both', bottom=False, left=False, labelbottom=False, labelleft=False) return text_items
[docs]def draw_circular(G, **kwargs): """Draw the graph G with a circular layout. Parameters ---------- G : graph A networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ draw(G, circular_layout(G), **kwargs)
[docs]def draw_kamada_kawai(G, **kwargs): """Draw the graph G with a Kamada-Kawai force-directed layout. Parameters ---------- G : graph A networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ draw(G, kamada_kawai_layout(G), **kwargs)
[docs]def draw_random(G, **kwargs): """Draw the graph G with a random layout. Parameters ---------- G : graph A networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ draw(G, random_layout(G), **kwargs)
[docs]def draw_spectral(G, **kwargs): """Draw the graph G with a spectral 2D layout. Using the unnormalized Laplacian, the layout shows possible clusters of nodes which are an approximation of the ratio cut. The positions are the entries of the second and third eigenvectors corresponding to the ascending eigenvalues starting from the second one. Parameters ---------- G : graph A networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ draw(G, spectral_layout(G), **kwargs)
[docs]def draw_spring(G, **kwargs): """Draw the graph G with a spring layout. Parameters ---------- G : graph A networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ draw(G, spring_layout(G), **kwargs)
[docs]def draw_shell(G, **kwargs): """Draw networkx graph with shell layout. Parameters ---------- G : graph A networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ nlist = kwargs.get('nlist', None) if nlist is not None: del(kwargs['nlist']) draw(G, shell_layout(G, nlist=nlist), **kwargs)
[docs]def draw_planar(G, **kwargs): """Draw a planar networkx graph with planar layout. Parameters ---------- G : graph A planar networkx graph kwargs : optional keywords See networkx.draw_networkx() for a description of optional keywords, with the exception of the pos parameter which is not used by this function. """ draw(G, planar_layout(G), **kwargs)
def apply_alpha(colors, alpha, elem_list, cmap=None, vmin=None, vmax=None): """Apply an alpha (or list of alphas) to the colors provided. Parameters ---------- colors : color string, or array of floats Color of element. Can be a single color format string (default='r'), or a sequence of colors with the same length as nodelist. If numeric values are specified they will be mapped to colors using the cmap and vmin,vmax parameters. See matplotlib.scatter for more details. alpha : float or array of floats Alpha values for elements. This can be a single alpha value, in which case it will be applied to all the elements of color. Otherwise, if it is an array, the elements of alpha will be applied to the colors in order (cycling through alpha multiple times if necessary). elem_list : array of networkx objects The list of elements which are being colored. These could be nodes, edges or labels. cmap : matplotlib colormap Color map for use if colors is a list of floats corresponding to points on a color mapping. vmin, vmax : float Minimum and maximum values for normalizing colors if a color mapping is used. Returns ------- rgba_colors : numpy ndarray Array containing RGBA format values for each of the node colours. """ from itertools import islice, cycle try: import numpy as np from matplotlib.colors import colorConverter import matplotlib.cm as cm except ImportError: raise ImportError("Matplotlib required for draw()") # If we have been provided with a list of numbers as long as elem_list, # apply the color mapping. if len(colors) == len(elem_list) and isinstance(colors[0], Number): mapper = cm.ScalarMappable(cmap=cmap) mapper.set_clim(vmin, vmax) rgba_colors = mapper.to_rgba(colors) # Otherwise, convert colors to matplotlib's RGB using the colorConverter # object. These are converted to numpy ndarrays to be consistent with the # to_rgba method of ScalarMappable. else: try: rgba_colors = np.array([colorConverter.to_rgba(colors)]) except ValueError: rgba_colors = np.array([colorConverter.to_rgba(color) for color in colors]) # Set the final column of the rgba_colors to have the relevant alpha values try: # If alpha is longer than the number of colors, resize to the number of # elements. Also, if rgba_colors.size (the number of elements of # rgba_colors) is the same as the number of elements, resize the array, # to avoid it being interpreted as a colormap by scatter() if len(alpha) > len(rgba_colors) or rgba_colors.size == len(elem_list): rgba_colors = np.resize(rgba_colors, (len(elem_list), 4)) rgba_colors[1:, 0] = rgba_colors[0, 0] rgba_colors[1:, 1] = rgba_colors[0, 1] rgba_colors[1:, 2] = rgba_colors[0, 2] rgba_colors[:, 3] = list(islice(cycle(alpha), len(rgba_colors))) except TypeError: rgba_colors[:, -1] = alpha return rgba_colors