ant3s.gif (2445 bytes)

Ant Colony System

Home Parameters Source Code Sample Runs Graphs

 

Sample run of graph88.tsp file:

This graph has 88 cities. The parameters we were using are:
Number of Ants=80
Beta = 2
Alpha = 0.2
P = 0.2
q0 = 0.4

To see the images, press the next links:
Loop 1 - best tour size = 140
Loop 2 - best tour size = 128.61
Loop 3 - best tour size = 132.19
Loop 4-5 - best tour size = 123.29
Loop 6 - best tour size = 118.68
Loop 7 - best tour size = 118.86
Loop 8 - best tour size = 116.28

Loop 8 is the best tour could be found for this graph.

graph6.gif (6808 bytes)

convergence.gif (3558 bytes)

 
Sample run of graph364.tsp file:

This graph has 364 cities. The parameters we were using are:
Number of Ants=80
Beta = 2
Alpha = 0.5
P = 0.2
q0 = 0.1
However, after the 22nd cycle we saw that there's no convergence, so we changed the parameters to explore less, and to give distance more weight over pheromone:
Beta = 4
q0 = 0.5

Click the next links to see the progress:
Loop 1 - best tour size = 1073.14
Loop 2 - best tour size = 879.13
Loop 3- best tour size = 889.19
Loop 4 - best tour size = 777.43
Loop 5 - best tour size = 884.92
Loop 6 - best tour size = 781.19
Loop 7 - best tour size = 860.58
Loop 8 - best tour size = 737.12
Loop 9 - best tour size = 849.13
Loop 10 - best tour size = 853.12
Loop 11 - best tour size = 909.39
Loop 12 - best tour size = 929.89
Loop 13 - best tour size = 852.70
Loop 14 - best tour size = 873.23
Loop 15 - best tour size = 863.25
Loop 16 - best tour size = 867.89
Loop 17 - best tour size = 842.15
Loop 18 - best tour size = 883.33
Loop 19 - best tour size = 896.48
Loop 20 - best tour size = 869.09
Loop 21 - best tour size = 839.82
Loop 22 - best tour size = 854.69
Loop 23 - best tour size = 692.15
Loop 24 - best tour size = 569.80
Loop 25 - best tour size = 544.50

 graph4.gif (16142 bytes)

convergence.gif (6900 bytes)

 

 

 

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