# HG changeset patch # User D. S. McNeil # Date 1298780544 -28800 # Node ID 253b3ec6a1100bf52a0fa2e72392325729cecc7e # Parent 8438b7c20d79c02a2ece3e1c3f7224a772ff8f07 Trac 10124: fix edge label locations diff -r 8438b7c20d79 -r 253b3ec6a110 sage/graphs/graph_plot.py --- a/sage/graphs/graph_plot.py Fri Feb 18 14:37:57 2011 +0000 +++ b/sage/graphs/graph_plot.py Sun Feb 27 12:22:24 2011 +0800 @@ -135,8 +135,27 @@ sage: T = list(graphs.trees(7)) sage: t = T[3] sage: t.plot(heights={0:[0], 1:[4,5,1], 2:[2], 3:[3,6]}) + + TESTS: + + Make sure that vertex locations are floats. Not being floats + isn't a bug in itself but makes it too easy to accidentally + introduce a bug elsewhere, such as in set_edges (trac #10124), + via silent truncating division of integers:: + + sage: g = graphs.FruchtGraph() + sage: gp = g.graphplot() + sage: set(map(type, flatten(gp._pos.values()))) + set([]) + sage: g = graphs.BullGraph() + sage: gp = g.graphplot(save_pos=True) + sage: set(map(type, flatten(gp._pos.values()))) + set([]) + """ self._pos = self._graph.layout(**self._options) + # make sure the positions are floats (trac #10124) + self._pos = dict((k,(float(v[0]), float(v[1]))) for k,v in self._pos.iteritems()) def set_vertices(self, **vertex_options): """ @@ -273,6 +292,26 @@ sage: G = Graph("Fooba") sage: G.show(edge_colors={'red':[(3,6),(2,5)]}) + Verify that default edge labels are pretty close to being between the vertices + in some cases where they weren't due to truncating division (trac #10124): + + sage: test_graphs = graphs.FruchtGraph(), graphs.BullGraph() + sage: tol = 0.001 + sage: for G in test_graphs: + ... E=G.edges() + ... for e0, e1, elab in E: + ... G.set_edge_label(e0, e1, '%d %d' % (e0, e1)) + ... gp = G.graphplot(save_pos=True,edge_labels=True) + ... vx = gp._plot_components['vertices'][0].xdata + ... vy = gp._plot_components['vertices'][0].ydata + ... for elab in gp._plot_components['edge_labels']: + ... textobj = elab[0] + ... x, y, s = textobj.x, textobj.y, textobj.string + ... v0, v1 = map(int, s.split()) + ... vn = vector(((x-(vx[v0]+vx[v1])/2.),y-(vy[v0]+vy[v1])/2.)).norm() + ... assert vn < tol + + """ for arg in edge_options: self._options[arg] = edge_options[arg] @@ -350,7 +389,7 @@ # Check for multi-edges or loops if self._arcs or self._loops: tmp = edges_to_draw.copy() - dist = self._options['dist']*2 + dist = self._options['dist']*2. loop_size = self._options['loop_size'] max_dist = self._options['max_dist'] from sage.functions.all import sqrt @@ -360,7 +399,7 @@ distance = dist local_labels = edges_to_draw.pop((a,b)) if len(local_labels)*dist > max_dist: - distance = max_dist/len(local_labels) + distance = float(max_dist)/len(local_labels) curr_loop_size = loop_size for i in range(len(local_labels)): self._plot_components['edges'].append(circle((self._pos[a][0],self._pos[a][1]-curr_loop_size), curr_loop_size, rgbcolor=local_labels[i][1], **eoptions)) @@ -374,15 +413,15 @@ # Compute perpendicular bisector p1 = self._pos[a] p2 = self._pos[b] - M = ((p1[0]+p2[0])/2, (p1[1]+p2[1])/2) # midpoint + M = ((p1[0]+p2[0])/2., (p1[1]+p2[1])/2.) # midpoint if not p1[1] == p2[1]: - S = (p1[0]-p2[0])/(p2[1]-p1[1]) # perp slope + S = float(p1[0]-p2[0])/(p2[1]-p1[1]) # perp slope y = lambda x : S*x-S*M[0]+M[1] # perp bisector line # f,g are functions of distance d to determine x values # on line y at d from point M - f = lambda d : sqrt(d**2/(1+S**2)) + M[0] - g = lambda d : -sqrt(d**2/(1+S**2)) + M[0] + f = lambda d : sqrt(d**2/(1.+S**2)) + M[0] + g = lambda d : -sqrt(d**2/(1.+S**2)) + M[0] odd_x = f even_x = g @@ -404,7 +443,7 @@ # (This is because we're using the perp bisectors). distance = dist if len(local_labels)*dist > max_dist: - distance = max_dist/len(local_labels) + distance = float(max_dist)/len(local_labels) for i in range(len(local_labels)/2): k = (i+1.0)*distance if self._arcdigraph: @@ -430,29 +469,41 @@ C,D = self._polar_hack_for_multidigraph(self._pos[a], self._pos[b], self._vertex_radius) self._plot_components['edges'].append(arrow(C,D, rgbcolor=edges_to_draw[(a,b)][0][1], head=edges_to_draw[(a,b)][0][2], **eoptions)) if labels: - self._plot_components['edge_labels'].append(text(str(edges_to_draw[(a,b)][0][0]),[(C[0]+D[0])/2, (C[1]+D[1])/2])) + self._plot_components['edge_labels'].append(text(str(edges_to_draw[(a,b)][0][0]),[(C[0]+D[0])/2., (C[1]+D[1])/2.])) elif dir: self._plot_components['edges'].append(arrow(self._pos[a],self._pos[b], rgbcolor=edges_to_draw[(a,b)][0][1], arrowshorten=self._arrowshorten, head=edges_to_draw[(a,b)][0][2], **eoptions)) else: self._plot_components['edges'].append(line([self._pos[a],self._pos[b]], rgbcolor=edges_to_draw[(a,b)][0][1], **eoptions)) if labels and not self._arcdigraph: - self._plot_components['edge_labels'].append(text(str(edges_to_draw[(a,b)][0][0]),[(self._pos[a][0]+self._pos[b][0])/2, (self._pos[a][1]+self._pos[b][1])/2])) + self._plot_components['edge_labels'].append(text(str(edges_to_draw[(a,b)][0][0]),[(self._pos[a][0]+self._pos[b][0])/2., (self._pos[a][1]+self._pos[b][1])/2.])) def _polar_hack_for_multidigraph(self, A, B, VR): """ Helper function to quickly compute the two points of intersection of a line - segment from A to B (xy tuples) and circles centered at A anb B, both with + segment from A to B (xy tuples) and circles centered at A and B, both with radius VR. Returns a tuple of xy tuples representing the two points. EXAMPLE: + sage: d = DiGraph({}, loops=True, multiedges=True, sparse=True) sage: d.add_edges([(0,0,'a'),(0,0,'b'),(0,1,'c'),(0,1,'d'), ... (0,1,'e'),(0,1,'f'),(0,1,'f'),(2,1,'g'),(2,2,'h')]) sage: GP = d.graphplot(vertex_size=100, edge_labels=True, color_by_label=True, edge_style='dashed') sage: GP._polar_hack_for_multidigraph((0,1),(1,1),.1) ([0.10..., 1.00...], [0.90..., 1.00...]) + + TESTS: + + Make sure that Python ints are acceptable arguments (trac #10124):: + + sage: GP = DiGraph().graphplot() + sage: GP._polar_hack_for_multidigraph((0, 1), (2, 2), .1) + ([0.08..., 1.04...], [1.91..., 1.95...]) + sage: GP._polar_hack_for_multidigraph((int(0),int(1)),(int(2),int(2)),.1) + ([0.08..., 1.04...], [1.91..., 1.95...]) + """ - D = [B[i]-A[i] for i in range(2)] + D = [float(B[i]-A[i]) for i in range(2)] R = sqrt(D[0]**2+D[1]**2) theta = 3*pi/2 if D[0] > 0: @@ -775,7 +826,7 @@ x = obstruction[y] pos[p] = x,y else: - x = sum([pos[c][0] for c in cp])/len(cp) + x = sum([pos[c][0] for c in cp])/(float(len(cp))) pos[p] = x,y ox = obstruction[y] if x < ox: