ENH: Graph visual

.travis.yml

@@ -137,7 +137,7 @@ install:
         if [ "${PYTHON}" == "2.6" ]; then
           conda install --yes --quiet wxpython numpy$NUMPY > ${REDIRECT_TO};
         else
-          conda install --yes --quiet ipython$IPYTHON ipython-notebook numpy$NUMPY > ${REDIRECT_TO};
+          conda install --yes --quiet ipython$IPYTHON ipython-notebook numpy$NUMPY networkx > ${REDIRECT_TO};
         fi;
         if [ "${PYTHON}" == "3.4" ]; then
           pip install -q freetype-py husl pypng cassowary https://github.com/mpld3/mplexporter/zipball/master > ${REDIRECT_TO};

examples/basics/scene/graph.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright (c) 2015, Vispy Development Team.
+# Distributed under the (new) BSD License. See LICENSE.txt for more info.
+
+"""
+This example demonstrates how to visualise a NetworkX graph using a VisPy
+Graph.
+"""
+
+import sys
+
+import networkx as nx
+
+from vispy import app, scene
+from vispy.visuals.graphs import layouts
+
+
+canvas = scene.SceneCanvas(title='Simple NetworkX Graph', size=(600, 600),
+                           bgcolor='white', show=True)
+view = canvas.central_widget.add_view('panzoom')
+
+graph = nx.adjacency_matrix(
+    nx.fast_gnp_random_graph(500, 0.005, directed=True))
+layout = layouts.get_layout('force_directed', iterations=100)
+
+visual = scene.visuals.Graph(
+    graph, layout=layout, line_color='black', arrow_type="stealth",
+    arrow_size=30, node_symbol="disc", node_size=20,
+    face_color=(1, 0, 0, 0.2), border_width=0.0, animate=True, directed=False,
+    parent=view.scene)
+
+
+@canvas.events.draw.connect
+def on_draw(event):
+    if not visual.animate_layout():
+        canvas.update()
+
+if __name__ == '__main__':
+    if sys.flags.interactive != 1:
+        app.run()

examples/basics/visuals/arrows_quiver.py

@@ -62,8 +62,8 @@ def on_resize(self, event):
         self.visual.transforms.configure(canvas=self, viewport=vp)
 
     def rotate_arrows(self, point_towards):
-        direction_vectors = (self.grid_coords -
-                             point_towards).astype(np.float32)
+        direction_vectors = (self.grid_coords - point_towards).astype(
+            np.float32)
         norms = np.sqrt(np.sum(direction_vectors**2, axis=-1))
         direction_vectors[:, 0] /= norms
         direction_vectors[:, 1] /= norms

examples/basics/visuals/graph.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright (c) 2015, Vispy Development Team.
+# Distributed under the (new) BSD License. See LICENSE.txt for more info.
+
+"""
+This example demonstrates how to visualise a NetworkX graph using the
+GraphVisual.
+"""
+
+import sys
+
+import networkx as nx
+
+from vispy import app, visuals
+from vispy.visuals.graphs import layouts
+from vispy.visuals.transforms import STTransform
+
+
+class Canvas(app.Canvas):
+    def __init__(self):
+        app.Canvas.__init__(self, title="Simple NetworkX Graph",
+                            keys="interactive", size=(600, 600))
+
+        graph = nx.adjacency_matrix(
+            nx.fast_gnp_random_graph(500, 0.005, directed=True))
+        layout = layouts.get_layout('force_directed', iterations=100)
+
+        self.visual = visuals.GraphVisual(
+            graph, layout=layout, line_color='black', arrow_type="stealth",
+            arrow_size=30, node_symbol="disc", node_size=20,
+            face_color=(1, 0, 0, 0.5), border_width=0.0, animate=True,
+            directed=False)
+
+        self.visual.transform = STTransform(self.visual_size, (20, 20))
+        self.show()
+
+    @property
+    def visual_size(self):
+        return self.physical_size[0] - 40, self.physical_size[1] - 40
+
+    def on_resize(self, event):
+        self.visual.transform.scale = self.visual_size
+        vp = (0, 0, self.physical_size[0], self.physical_size[1])
+        self.context.set_viewport(*vp)
+        self.visual.transforms.configure(canvas=self, viewport=vp)
+
+    def on_draw(self, event):
+        self.context.clear('white')
+        self.visual.draw()
+        if not self.visual.animate_layout():
+            self.update()
+
+
+if __name__ == '__main__':
+    win = Canvas()
+
+    if sys.flags.interactive != 1:
+        app.run()

vispy/scene/visuals.py

@@ -232,6 +232,7 @@ def generate_docstring(subclass, clsname):
 Compound = create_visual_node(visuals.CompoundVisual)
 Cube = create_visual_node(visuals.CubeVisual)
 Ellipse = create_visual_node(visuals.EllipseVisual)
+Graph = create_visual_node(visuals.GraphVisual)
 GridLines = create_visual_node(visuals.GridLinesVisual)
 GridMesh = create_visual_node(visuals.GridMeshVisual)
 Histogram = create_visual_node(visuals.HistogramVisual)

vispy/visuals/__init__.py

@@ -41,3 +41,4 @@
 from .xyz_axis import XYZAxisVisual  # noqa
 from .border import _BorderVisual  # noqa
 from .colorbar import ColorBarVisual  # noqa
+from .graphs import GraphVisual  # noqa

vispy/visuals/graphs/__init__.py

@@ -0,0 +1 @@
+from .graph import GraphVisual  # noqa

vispy/visuals/graphs/graph.py

@@ -0,0 +1,212 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2015, Vispy Development Team.
+# Distributed under the (new) BSD License. See LICENSE.txt for more info.
+"""
+Graph Visual
+============
+
+This visual can be used to visualise graphs or networks.
+"""
+
+from ..visual import CompoundVisual
+from ..line import ArrowVisual
+from ..markers import MarkersVisual
+from . import layouts
+
+
+class GraphVisual(CompoundVisual):
+    """Visual for displaying graphs or networks.
+
+    Parameters
+    ----------
+    adjacency_mat : array or sparse
+        The adjacency matrix of the graph.
+    directed : bool
+        Whether the graph is directed or not. If True, then this visual will
+        draw arrows for the directed edges.
+    line_color : str or :class:`vispy.color.colormap.ColorMap`
+        The color to use for the edges.
+    line_width : number
+        The edge thickness.
+    arrow_type : str
+        The kind of arrow head to use. See :class:`vispy.visuals.ArrowHead`
+        for more information.
+    arrow_size : number
+        The size of the arrow head.
+    node_symbol : string
+        The marker to use for nodes. See
+        :class:`vispy.visuals.MarkersVisual` for more information.
+    node_size : number
+        The size of the node
+    border_color : str or :class:`vispy.color.colormap.ColorMap`
+        The border color for nodes.
+    face_color : str or :class:`vispy.color.colormap.ColorMap`
+        The face color for nodes.
+    border_width : number
+        The border size for nodes.
+
+    See Also
+    --------
+    ArrowVisual, MarkersVisual
+
+    """
+
+    _arrow_attributes = ('arrow_type', 'arrow_size')
+    _arrow_kwargs = ('line_color', 'line_width')
+    _node_kwargs = ('node_symbol', 'node_size', 'border_color', 'face_color',
+                    'border_width')
+
+    _arrow_kw_trans = dict(line_color='color', line_width='width')
+    _node_kw_trans = dict(node_symbol='symbol', node_size='size',
+                          border_color='edge_color', border_width='edge_width')
+
+    def __init__(self, adjacency_mat=None, directed=False, layout=None,
+                 animate=False, line_color=None, line_width=None,
+                 arrow_type=None, arrow_size=None, node_symbol=None,
+                 node_size=None, border_color=None, face_color=None,
+                 border_width=None):
+
+        self._edges = ArrowVisual(method='gl', connect='segments')
+        self._nodes = MarkersVisual()
+
+        self._arrow_data = {}
+        self._node_data = {}
+
+        self._adjacency_mat = None
+
+        self._layout = None
+        self._layout_iter = None
+        self.layout = layout
+
+        self._directed = directed
+        self.directed = directed
+
+        self._animate = False
+        self.animate = animate
+
+        CompoundVisual.__init__(self, [self._edges, self._nodes])
+
+        self.set_data(adjacency_mat, line_color=line_color,
+                      line_width=line_width, arrow_type=arrow_type,
+                      arrow_size=arrow_size, node_symbol=node_symbol,
+                      node_size=node_size, border_color=border_color,
+                      face_color=face_color, border_width=border_width)
+
+    @property
+    def adjacency_matrix(self):
+        return self._adjacency_mat
+
+    @property
+    def layout(self):
+        return self._layout
+
+    @layout.setter
+    def layout(self, value):
+        if type(value) == str:
+            self._layout = layouts.get_layout(value)
+        else:
+            assert callable(value)
+            self._layout = value
+
+        self._layout_iter = None
+
+    @property
+    def directed(self):
+        return self._directed
+
+    @directed.setter
+    def directed(self, value):
+        self._directed = bool(value)
+
+    @property
+    def animate(self):
+        return self._animate
+
+    @animate.setter
+    def animate(self, value):
+        self._animate = bool(value)
+
+    def animate_layout(self):
+        if self._layout_iter is None:
+            if self._adjacency_mat is None:
+                raise ValueError("No adjacency matrix set yet. An adjacency "
+                                 "matrix is required to calculate the layout.")
+
+            self._layout_iter = iter(self._layout(self._adjacency_mat,
+                                                  self._directed))
+
+        try:
+            node_vertices, line_vertices, arrows = next(self._layout_iter)
+        except StopIteration:
+            return True
+
+        self._nodes.set_data(pos=node_vertices, **self._node_data)
+        self._edges.set_data(pos=line_vertices, arrows=arrows,
+                             **self._arrow_data)
+
+        return False
+
+    def set_final_layout(self):
+        if self._layout_iter is None:
+            if self._adjacency_mat is None:
+                raise ValueError("No adjacency matrix set yet. An adjacency "
+                                 "matrix is required to calculate the layout.")
+
+            self._layout_iter = iter(self._layout(self._adjacency_mat,
+                                                  self._directed))
+
+        # Calculate the final position of the nodes and lines
+        node_vertices = None
+        line_vertices = None
+        arrows = None
+        for node_vertices, line_vertices, arrows in self._layout_iter:
+            pass
+
+        self._nodes.set_data(pos=node_vertices, **self._node_data)
+        self._edges.set_data(pos=line_vertices, arrows=arrows,
+                             **self._arrow_data)
+
+    def reset_layout(self):
+        self._layout_iter = None
+
+    def set_data(self, adjacency_mat=None, **kwargs):
+        if adjacency_mat is not None:
+            if adjacency_mat.shape[0] != adjacency_mat.shape[1]:
+                raise ValueError("Adjacency matrix should be square.")
+
+            self._adjacency_mat = adjacency_mat
+
+        for k in self._arrow_attributes:
+            if k in kwargs:
+                translated = (self._arrow_kw_trans[k] if k in
+                              self._arrow_kw_trans else k)
+
+                setattr(self._edges, translated, kwargs.pop(k))
+
+        arrow_kwargs = {}
+        for k in self._arrow_kwargs:
+            if k in kwargs:
+                translated = (self._arrow_kw_trans[k] if k in
+                              self._arrow_kw_trans else k)
+
+                arrow_kwargs[translated] = kwargs.pop(k)
+
+        node_kwargs = {}
+        for k in self._node_kwargs:
+            if k in kwargs:
+                translated = (self._node_kw_trans[k] if k in
+                              self._node_kw_trans else k)
+
+                node_kwargs[translated] = kwargs.pop(k)
+
+        if len(kwargs) > 0:
+            raise TypeError("%s.set_data() got invalid keyword arguments: %S"
+                            % (self.__class__.__name__, list(kwargs.keys())))
+
+        # The actual data is set in GraphVisual.animate_layout or
+        # GraphVisual.set_final_layout
+        self._arrow_data = arrow_kwargs
+        self._node_data = node_kwargs
+
+        if not self._animate:
+            self.set_final_layout()