gambit-ipa

Compute Nash equilibria in a strategic game using iterated polymatrix approximation. See the algorithm description for full details.

The algorithm finds at most one equilibrium starting from any given profile. Multiple starting profiles may be generated via the -n option or specified via the -s option; different starting profiles may result in different equilibria being found.

-d

Express all output using decimal representations with the specified number of digits.

-h

Prints a help message listing the available options.

-n

Randomly generate the specified number of perturbation vectors. Mutually exclusive with -s.

-R

Seeds the random number generator used to generate perturbation vectors with the specified value, so that the sequence of vectors generated by -n can be reproduced across runs. If not specified, the generator is seeded from system entropy. Requires -n.

-q

Suppresses printing of the banner at program launch.

-s

Specifies a file containing a list of starting points for the algorithm. The format of the file is comma-separated values, one mixed strategy profile per line, in the same format used for output of equilibria (excluding the initial NE tag). Mutually exclusive with -n.

-V, --verbose

Show intermediate output of the algorithm. If this option is not specified, only the equilibria found are reported.

-v, --version

Prints version information and exits.

Computing an equilibrium of the reduced strategic form of the example in Figure 2 of [Sel75]:

$ gambit-ipa catalog/games/journals/ijgt/selten1975/fig2.efg
Compute Nash equilibria using iterated polymatrix approximation
Gametracer version 0.2, Copyright (C) 2002, Ben Blum and Christian Shelton
Gambit version |release|, Copyright (C) 1994-2026, The Gambit Project
This is free software, distributed under the GNU GPL

NE,1.000000,0.000000,0.000000,1.000000,0.000000

See also

gambit-gnm.