1gv(3lua) gv(3lua)
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6 gv_lua - graph manipulation in lua
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10 #!/usr/bin/lua
11 require('gv')
12
16 gv_lua is a dynamically loaded extension for lua that provides access
17 to the graph facilities of graphviz.
18
21 New graphs
22 New empty graph
24 graph_handle gv.graph (name);
25 graph_handle gv.digraph (name);
26 graph_handle gv.strictgraph (name);
27 graph_handle gv.strictdigraph (name);
28 New graph from a dot-syntax string or file
30 graph_handle gv.readstring (string);
31 graph_handle gv.read (string filename);
32 graph_handle gv.read (channel);
33 Add new subgraph to existing graph
35 graph_handle gv.graph (graph_handle, name);
36 New nodes
38 Add new node to existing graph
40 node_handle gv.node (graph_handle, name);
41 New edges
43 Add new edge between existing nodes
45 edge_handle gv.edge (tail_node_handle, head_node_handle);
46 Add a new edge between an existing tail node, and a named head node
48 which will be induced in the graph if it doesn't already exist
49 edge_handle gv.edge (tail_node_handle, head_name);
50 Add a new edge between an existing head node, and a named tail node
52 which will be induced in the graph if it doesn't already exist
53 edge_handle gv.edge (tail_name, head_node_handle);
54 Add a new edge between named tail and head nodes which will be induced
56 in the graph if they don't already exist
57 edge_handle gv.edge (graph_handle, tail_name, head_name);
58 Setting attribute values
60 Set value of named attribute of graph/node/edge - creating attribute if
62 necessary
63 string gv.setv (graph_handle, attr_name, attr_value);
64 string gv.setv (node_handle, attr_name, attr_value);
65 string gv.setv (edge_handle, attr_name, attr_value);
66 Set value of existing attribute of graph/node/edge (using attribute
68 handle)
69 string gv.setv (graph_handle, attr_handle, attr_value);
70 string gv.setv (node_handle, attr_handle, attr_value);
71 string gv.setv (edge_handle, attr_handle, attr_value);
72 Getting attribute values
74 Get value of named attribute of graph/node/edge
76 string gv.getv (graph_handle, attr_name);
77 string gv.getv (node_handle, attr_name);
78 string gv.getv (edge_handle, attr_name);
79 Get value of attribute of graph/node/edge (using attribute handle)
81 string gv.getv (graph_handle, attr_handle);
82 string gv.getv (node_handle, attr_handle);
83 string gv.getv (edge_handle, attr_handle);
84 Obtain names from handles
86 string gv.nameof (graph_handle);
87 string gv.nameof (node_handle);
88 string gv.nameof (attr_handle);
89 Find handles from names
91 graph_handle gv.findsubg (graph_handle, name);
92 node_handle gv.findnode (graph_handle, name);
93 edge_handle gv.findedge (tail_node_handle, head_node_handle);
94 attribute_handle gv.findattr (graph_handle, name);
95 attribute_handle gv.findattr (node_handle, name);
96 attribute_handle gv.findattr (edge_handle, name);
97 Misc graph navigators returning handles
99 node_handle gv.headof (edge_handle);
100 node_handle gv.tailof (edge_handle);
101 graph_handle gv.graphof (graph_handle);
102 graph_handle gv.graphof (edge_handle);
103 graph_handle gv.graphof (node_handle);
104 graph_handle gv.rootof (graph_handle);
105 Obtain handles of proto node/edge for setting default attribute values
107 node_handle gv.protonode (graph_handle);
108 edge_handle gv.protoedge (graph_handle);
109 Iterators
111 Iteration termination tests
113 bool gv.ok (graph_handle);
114 bool gv.ok (node_handle);
115 bool gv.ok (edge_handle);
116 bool gv.ok (attr_handle);
117 Iterate over subgraphs of a graph
119 graph_handle gv.firstsubg (graph_handle);
120 graph_handle gv.nextsubg (graph_handle, subgraph_handle);
121 Iterate over supergraphs of a graph (obscure and rarely useful)
123 graph_handle gv.firstsupg (graph_handle);
124 graph_handle gv.nextsupg (graph_handle, subgraph_handle);
125 Iterate over edges of a graph
127 edge_handle gv.firstedge (graph_handle);
128 edge_handle gv.nextedge (graph_handle, edge_handle);
129 Iterate over outedges of a graph
131 edge_handle gv.firstout (graph_handle);
132 edge_handle gv.nextout (graph_handle, edge_handle);
133 Iterate over edges of a node
135 edge_handle gv.firstedge (node_handle);
136 edge_handle gv.nextedge (node_handle, edge_handle);
137 Iterate over out-edges of a node
139 edge_handle gv.firstout (node_handle);
140 edge_handle gv.nextout (node_handle, edge_handle);
141 Iterate over head nodes reachable from out-edges of a node
143 node_handle gv.firsthead (node_handle);
144 node_handle gv.nexthead (node_handle, head_node_handle);
145 Iterate over in-edges of a graph
147 edge_handle gv.firstin (graph_handle);
148 edge_handle gv.nextin (node_handle, edge_handle);
149 Iterate over in-edges of a node
151 edge_handle gv.firstin (node_handle);
152 edge_handle gv.nextin (graph_handle, edge_handle);
153 Iterate over tail nodes reachable from in-edges of a node
155 node_handle gv.firsttail (node_handle);
156 node_handle gv.nexttail (node_handle, tail_node_handle);
157 Iterate over nodes of a graph
159 node_handle gv.firstnode (graph_handle);
160 node_handle gv.nextnode (graph_handle, node_handle);
161 Iterate over nodes of an edge
163 node_handle gv.firstnode (edge_handle);
164 node_handle gv.nextnode (edge_handle, node_handle);
165 Iterate over attributes of a graph
167 attribute_handle gv.firstattr (graph_handle);
168 attribute_handle gv.nextattr (graph_handle, attr_handle);
169 Iterate over attributes of an edge
171 attribute_handle gv.firstattr (edge_handle);
172 attribute_handle gv.nextattr (edge_handle, attr_handle);
173 Iterate over attributes of a node
175 attribute_handle gv.firstattr (node_handle);
176 attribute_handle gv.nextattr (node_handle, attr_handle);
177 Remove graph objects
179 bool gv.rm (graph_handle);
180 bool gv.rm (node_handle);
181 bool gv.rm (edge_handle);
182 Layout
184 Annotate a graph with layout attributes and values using a specific
186 layout engine
187 bool gv.layout (graph_handle, string engine);
188 Render
190 Render a layout into attributes of the graph
192 bool gv.render (graph_handle);
193 Render a layout to stdout
195 bool gv.render (graph_handle, string format);
196 Render to an open file
198 bool gv.render (graph_handle, string format, channel fout);
199 Render a layout to an unopened file by name
201 bool gv.render (graph_handle, string format, string filename);
202 Render to a string result
204 string gv.renderresult (graph_handle ing, string format);
205 gv.renderresult (graph_handle, string format, string outdata);
206 Render to an open channel
208 bool gv.renderchannel (graph_handle, string format, string chan‐
209 nelname);
210 Render a layout to a malloc'ed string, to be free'd by the caller
212 (deprecated - too easy to leak memory)
214 (still needed for "eval [gv::renderdata $G tk]" )
216 string gv.renderdata (graph_handle, string format);
217 Writing graph back to file
219 bool gv.write (graph_handle, string filename);
220 bool gv.write (graph_handle, channel);
221 Graph transformation tools
223 bool gv.tred (graph_handle);
224
227 graph, dot, neato, fdp, circo, twopi, lua.
228 26 May 2021 gv(3lua)