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1 # Copyright (c) 2007-2008 Pedro Matiello <pmatiello@gmail.com> |
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2 # Zsolt Haraszti <zsolt@drawwell.net> |
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3 # |
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4 # Permission is hereby granted, free of charge, to any person |
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5 # obtaining a copy of this software and associated documentation |
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6 # files (the "Software"), to deal in the Software without |
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7 # restriction, including without limitation the rights to use, |
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8 # copy, modify, merge, publish, distribute, sublicense, and/or sell |
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9 # copies of the Software, and to permit persons to whom the |
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10 # Software is furnished to do so, subject to the following |
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11 # conditions: |
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12 |
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13 # The above copyright notice and this permission notice shall be |
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14 # included in all copies or substantial portions of the Software. |
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15 |
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16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
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17 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
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18 # OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
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19 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
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20 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
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21 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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22 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
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23 # OTHER DEALINGS IN THE SOFTWARE. |
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24 |
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25 |
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26 """ |
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27 Random graph generators for python-graph. |
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28 |
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29 @sort: generate |
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30 """ |
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31 |
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32 |
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33 # Imports |
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34 import graph as classes |
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35 from random import randint |
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36 |
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37 |
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38 # Generator |
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39 |
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40 def generate(graph, num_nodes, num_edges, weight_range=(1, 1)): |
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41 """ |
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42 Add nodes and random edges to the graph. |
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43 |
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44 @type graph: graph |
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45 @param graph: Graph. |
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46 |
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47 @type num_nodes: number |
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48 @param num_nodes: Number of nodes. |
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49 |
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50 @type num_edges: number |
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51 @param num_edges: Number of edges. |
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52 |
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53 @type weight_range: tuple |
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54 @param weight_range: tuple of two integers as lower and upper limits on randomly generated |
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55 weights (uniform distribution). |
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56 """ |
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57 # Discover if graph is directed or not |
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58 directed = (type(graph) == classes.digraph) |
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59 |
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60 # Nodes first |
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61 nodes = xrange(num_nodes) |
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62 graph.add_nodes(nodes) |
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63 |
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64 # Build a list of all possible edges |
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65 edges = [] |
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66 edges_append = edges.append |
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67 for x in nodes: |
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68 for y in nodes: |
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69 if ((directed and x != y) or (x > y)): |
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70 edges_append((x, y)) |
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71 |
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72 # Randomize the list |
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73 for i in xrange(len(edges)): |
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74 r = randint(0, len(edges)-1) |
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75 edges[i], edges[r] = edges[r], edges[i] |
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76 |
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77 # Add edges to the graph |
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78 min_wt = min(weight_range) |
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79 max_wt = max(weight_range) |
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80 for i in xrange(num_edges): |
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81 each = edges[i] |
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82 graph.add_edge(each[0], each[1], wt = randint(min_wt, max_wt)) |