• aolibILP
• Demo

aolibILP step-by-step instructions

In the following we provide step-by-step instructions on how to use the aolibILP algorithm on an example problem instance. This example is based on Windows, but the steps for Linux are almost the same.

Downloading and running the algorithm

1. Download the archive with the executable from the algorithm's page. Since we assume a Windows operating system here, we need this file.

2. Unpack the archive contents (the binary and a sample parameter file) into a directory of your choice, say C:\aolib\.

3. Obtain an MPS file of a ILP problem instance, for instance from our local Repository. For this example we pick p0201 from the MIPLIB problem set.

4. The problem instance file comes in gzip'ed form, so unpack it to the same directory as the algorithm executable; in our case C:\aolib\.¹

5. Open a command line (In Windows: Choose "Run" in the start menu and enter cmd) and navigate to the directory where we put the files by entering cd C:\aolib\.

6. Run the algorithm according to the algorithm's page. We'll use AND/OR Branch-and-Bound graph search and enable verbosity, so the command line call in our case will be:

   aolibILP-win32.exe -f p0201.mps -h hypergraph -a 3 -v yes

Algorithm output

The algorithm will run and, depending on the speed of your computer, the result should be returned shortly afterwards. The output should look somewhat like this:

PP: forced connected:           no
PP: number of variables:        201
PP: number of functions:        133
PP: domain size bound:          2
PP: constraint arity:           67
PP: induced width:              120
PP: pseudo-tree depth:          142
PP: number of nodes in graph:   201
PP: number of edges in graph:   7497
PP: graph density:              37.2985 %
PP: preprocessing time:         0 seconds
PP: pseudo-tree time:           1.907 seconds

AOBB started ...
   time limit:  -1
   c-bound:     10000
   cache sch:   classic
   cache impl:  hash
   # cached:    33
   simplex:     lp_solve 5.5.0.9
   ordering:    SVO
    -time        1.0, nodes 281, open 31, closed 283
    -time        2.0, nodes 637, open 26, closed 219
    -time        3.0, nodes 971, open 17, closed 121
    -time        4.0, nodes 1236, open 24, closed 173
    -time        5.0, nodes 1475, open 16, closed 115
    -time        6.0, nodes 1655, open 25, closed 183
    -time        7.0, nodes 1867, open 10, closed 67
    -time        8.0, nodes 2062, open 23, closed 167
    -time        9.0, nodes 2256, open 27, closed 239
    -time       10.0, nodes 2486, open 12, closed 109
    -time       11.0, nodes 2664, open 23, closed 195
    -time       12.0, nodes 2825, open 16, closed 131
    -time       13.0, nodes 2993, open 13, closed 105
    -time       14.0, nodes 3152, open 13, closed 97
    -time       15.0, nodes 3301, open 8, closed 83
    -time       16.0, nodes 3440, open 5, closed 49
    -time       17.0, nodes 3576, open 11, closed 89
    -time       18.0, nodes 3707, open 10, closed 77
    -time       19.0, nodes 3841, open 4, closed 37
    -time       20.0, nodes 3973, open 8, closed 61
    -time       21.0, nodes 4102, open 10, closed 85
    -time       22.0, nodes 4228, open 5, closed 43
    -time       23.0, nodes 4361, open 9, closed 79
    -time       24.0, nodes 4490, open 8, closed 77
    -time       25.0, nodes 4615, open 15, closed 125
    -time       26.0, nodes 4743, open 10, closed 87
    -time       27.0, nodes 4875, open 14, closed 117
    -time       28.0, nodes 4992, open 8, closed 79
    -time       29.0, nodes 5121, open 12, closed 101
    -time       30.0, nodes 5306, open 15, closed 119
    -time       31.0, nodes 5476, open 9, closed 75
    -time       32.0, nodes 5611, open 13, closed 115
    -time       33.0, nodes 5737, open 7, closed 69
    -time       34.0, nodes 5861, open 5, closed 39
    -time       35.0, nodes 5972, open 7, closed 59
    -time       36.0, nodes 6088, open 5, closed 53
    -time       37.0, nodes 6213, open 4, closed 49
    -time       38.0, nodes 6337, open 4, closed 35
    -time       39.0, nodes 6462, open 6, closed 65
    -time       40.0, nodes 6587, open 12, closed 97
    -time       41.0, nodes 6706, open 8, closed 79
    -time       42.0, nodes 6836, open 4, closed 45
    -time       43.0, nodes 6954, open 10, closed 77
    -time       44.0, nodes 7085, open 14, closed 125
    -time       45.0, nodes 7216, open 11, closed 105
    -time       46.0, nodes 7348, open 8, closed 77
    -time       47.0, nodes 7458, open 3, closed 35
    -time       48.0, nodes 7587, open 5, closed 49
    -time       49.0, nodes 7708, open 2, closed 47
    -time       50.0, nodes 7827, open 8, closed 81
    -time       51.0, nodes 7944, open 6, closed 51
    -time       52.0, nodes 8064, open 9, closed 79
    -time       53.0, nodes 8192, open 9, closed 85
    -time       54.0, nodes 8321, open 11, closed 99
    -time       55.0, nodes 8441, open 8, closed 97
    -time       56.0, nodes 8551, open 4, closed 47
    -time       57.0, nodes 8690, open 13, closed 137
    -time       58.0, nodes 8816, open 7, closed 79
    -time       59.0, nodes 8936, open 6, closed 77
    -time       60.0, nodes 9067, open 4, closed 71
   out of time: no
   optimal solution cost:       7615
   CPU time (preproc):        1.9070
   CPU time (search):        60.1250
   CPU time (total):         62.0320
   number of nodes:             9076
   memory usage:                0.0022 MB
END.

In addition to this diagnostic output, aolibILP also outputs/appends a short summary of its computation to the file summary.txt, which you should feel free to look at.