"""
Symmetric linear games and their solutions.
-This module contains the main SymmetricLinearGame class that knows how
-to solve a linear game.
+This module contains the main :class:`SymmetricLinearGame` class that
+knows how to solve a linear game.
"""
# These few are used only for tests.
"""
A representation of the solution of a linear game. It should contain
the value of the game, and both players' strategies.
+
+ Examples
+ --------
+
+ >>> print(Solution(10, matrix([1,2]), matrix([3,4])))
+ Game value: 10.0000000
+ Player 1 optimal:
+ [ 1]
+ [ 2]
+ Player 2 optimal:
+ [ 3]
+ [ 4]
+
"""
def __init__(self, game_value, p1_optimal, p2_optimal):
"""
* The optimal strategy of player one.
* The optimal strategy of player two.
- EXAMPLES:
-
- >>> print(Solution(10, matrix([1,2]), matrix([3,4])))
- Game value: 10.0000000
- Player 1 optimal:
- [ 1]
- [ 2]
- Player 2 optimal:
- [ 3]
- [ 4]
-
+ The two optimal strategy vectors are indented by two spaces.
"""
tpl = 'Game value: {:.7f}\n' \
'Player 1 optimal:{:s}\n' \
def game_value(self):
"""
Return the game value for this solution.
+
+ Examples
+ --------
+
+ >>> s = Solution(10, matrix([1,2]), matrix([3,4]))
+ >>> s.game_value()
+ 10
+
"""
return self._game_value
def player1_optimal(self):
"""
Return player one's optimal strategy in this solution.
+
+ Examples
+ --------
+
+ >>> s = Solution(10, matrix([1,2]), matrix([3,4]))
+ >>> print(s.player1_optimal())
+ [ 1]
+ [ 2]
+ <BLANKLINE>
+
"""
return self._player1_optimal
def player2_optimal(self):
"""
Return player two's optimal strategy in this solution.
+
+ Examples
+ --------
+
+ >>> s = Solution(10, matrix([1,2]), matrix([3,4]))
+ >>> print(s.player2_optimal())
+ [ 3]
+ [ 4]
+ <BLANKLINE>
+
"""
return self._player2_optimal
two respectively.
The ambient space is assumed to be the span of ``K``.
+
+ Examples
+ --------
+
+ >>> from cones import NonnegativeOrthant
+ >>> K = NonnegativeOrthant(3)
+ >>> L = [[1,-5,-15],[-1,2,-3],[-12,-15,1]]
+ >>> e1 = [1,1,1]
+ >>> e2 = [1,2,3]
+ >>> SLG = SymmetricLinearGame(L, K, e1, e2)
+ >>> print(SLG)
+ The linear game (L, K, e1, e2) where
+ L = [ 1 -5 -15]
+ [ -1 2 -3]
+ [-12 -15 1],
+ K = Nonnegative orthant in the real 3-space,
+ e1 = [ 1]
+ [ 1]
+ [ 1],
+ e2 = [ 1]
+ [ 2]
+ [ 3].
+
+
+ Lists can (and probably should) be used for every argument::
+
+ >>> from cones import NonnegativeOrthant
+ >>> K = NonnegativeOrthant(2)
+ >>> L = [[1,0],[0,1]]
+ >>> e1 = [1,1]
+ >>> e2 = [1,1]
+ >>> G = SymmetricLinearGame(L, K, e1, e2)
+ >>> print(G)
+ The linear game (L, K, e1, e2) where
+ L = [ 1 0]
+ [ 0 1],
+ K = Nonnegative orthant in the real 2-space,
+ e1 = [ 1]
+ [ 1],
+ e2 = [ 1]
+ [ 1].
+
+ The points ``e1`` and ``e2`` can also be passed as some other
+ enumerable type (of the correct length) without much harm, since
+ there is no row/column ambiguity::
+
+ >>> import cvxopt
+ >>> import numpy
+ >>> from cones import NonnegativeOrthant
+ >>> K = NonnegativeOrthant(2)
+ >>> L = [[1,0],[0,1]]
+ >>> e1 = cvxopt.matrix([1,1])
+ >>> e2 = numpy.matrix([1,1])
+ >>> G = SymmetricLinearGame(L, K, e1, e2)
+ >>> print(G)
+ The linear game (L, K, e1, e2) where
+ L = [ 1 0]
+ [ 0 1],
+ K = Nonnegative orthant in the real 2-space,
+ e1 = [ 1]
+ [ 1],
+ e2 = [ 1]
+ [ 1].
+
+ However, ``L`` will always be intepreted as a list of rows, even
+ if it is passed as a :class:`cvxopt.base.matrix` which is
+ otherwise indexed by columns::
+
+ >>> import cvxopt
+ >>> from cones import NonnegativeOrthant
+ >>> K = NonnegativeOrthant(2)
+ >>> L = [[1,2],[3,4]]
+ >>> e1 = [1,1]
+ >>> e2 = e1
+ >>> G = SymmetricLinearGame(L, K, e1, e2)
+ >>> print(G)
+ The linear game (L, K, e1, e2) where
+ L = [ 1 2]
+ [ 3 4],
+ K = Nonnegative orthant in the real 2-space,
+ e1 = [ 1]
+ [ 1],
+ e2 = [ 1]
+ [ 1].
+ >>> L = cvxopt.matrix(L)
+ >>> print(L)
+ [ 1 3]
+ [ 2 4]
+ <BLANKLINE>
+ >>> G = SymmetricLinearGame(L, K, e1, e2)
+ >>> print(G)
+ The linear game (L, K, e1, e2) where
+ L = [ 1 2]
+ [ 3 4],
+ K = Nonnegative orthant in the real 2-space,
+ e1 = [ 1]
+ [ 1],
+ e2 = [ 1]
+ [ 1].
+
"""
def __init__(self, L, K, e1, e2):
"""
+ Create a new SymmetricLinearGame object.
+
INPUT:
- ``L`` -- an square matrix represented as a list of lists
- ``e2`` -- the interior point of ``K`` belonging to player two;
it can be of any enumerable type having the correct length.
- EXAMPLES:
-
- Lists can (and probably should) be used for every argument:
-
- >>> from cones import NonnegativeOrthant
- >>> K = NonnegativeOrthant(2)
- >>> L = [[1,0],[0,1]]
- >>> e1 = [1,1]
- >>> e2 = [1,1]
- >>> G = SymmetricLinearGame(L, K, e1, e2)
- >>> print(G)
- The linear game (L, K, e1, e2) where
- L = [ 1 0]
- [ 0 1],
- K = Nonnegative orthant in the real 2-space,
- e1 = [ 1]
- [ 1],
- e2 = [ 1]
- [ 1].
-
- The points ``e1`` and ``e2`` can also be passed as some other
- enumerable type (of the correct length) without much harm, since
- there is no row/column ambiguity:
-
- >>> import cvxopt
- >>> import numpy
- >>> from cones import NonnegativeOrthant
- >>> K = NonnegativeOrthant(2)
- >>> L = [[1,0],[0,1]]
- >>> e1 = cvxopt.matrix([1,1])
- >>> e2 = numpy.matrix([1,1])
- >>> G = SymmetricLinearGame(L, K, e1, e2)
- >>> print(G)
- The linear game (L, K, e1, e2) where
- L = [ 1 0]
- [ 0 1],
- K = Nonnegative orthant in the real 2-space,
- e1 = [ 1]
- [ 1],
- e2 = [ 1]
- [ 1].
-
- However, ``L`` will always be intepreted as a list of rows, even
- if it is passed as a ``cvxopt.base.matrix`` which is otherwise
- indexed by columns:
-
- >>> import cvxopt
- >>> from cones import NonnegativeOrthant
- >>> K = NonnegativeOrthant(2)
- >>> L = [[1,2],[3,4]]
- >>> e1 = [1,1]
- >>> e2 = e1
- >>> G = SymmetricLinearGame(L, K, e1, e2)
- >>> print(G)
- The linear game (L, K, e1, e2) where
- L = [ 1 2]
- [ 3 4],
- K = Nonnegative orthant in the real 2-space,
- e1 = [ 1]
- [ 1],
- e2 = [ 1]
- [ 1].
- >>> L = cvxopt.matrix(L)
- >>> print(L)
- [ 1 3]
- [ 2 4]
- <BLANKLINE>
- >>> G = SymmetricLinearGame(L, K, e1, e2)
- >>> print(G)
- The linear game (L, K, e1, e2) where
- L = [ 1 2]
- [ 3 4],
- K = Nonnegative orthant in the real 2-space,
- e1 = [ 1]
- [ 1],
- e2 = [ 1]
- [ 1].
"""
self._K = K
self._e1 = matrix(e1, (K.dimension(), 1))
def __str__(self):
"""
- Return a string representatoin of this game.
-
- EXAMPLES:
-
- >>> from cones import NonnegativeOrthant
- >>> K = NonnegativeOrthant(3)
- >>> L = [[1,-5,-15],[-1,2,-3],[-12,-15,1]]
- >>> e1 = [1,1,1]
- >>> e2 = [1,2,3]
- >>> SLG = SymmetricLinearGame(L, K, e1, e2)
- >>> print(SLG)
- The linear game (L, K, e1, e2) where
- L = [ 1 -5 -15]
- [ -1 2 -3]
- [-12 -15 1],
- K = Nonnegative orthant in the real 3-space,
- e1 = [ 1]
- [ 1]
- [ 1],
- e2 = [ 1]
- [ 2]
- [ 3].
-
+ Return a string representation of this game.
"""
tpl = 'The linear game (L, K, e1, e2) where\n' \
' L = {:s},\n' \
GameUnsolvableException is raised. It can be printed to get the
raw output from CVXOPT.
- EXAMPLES:
+ Examples
+ --------
This example is computed in Gowda and Ravindran in the section
- "The value of a Z-transformation":
+ "The value of a Z-transformation"::
>>> from cones import NonnegativeOrthant
>>> K = NonnegativeOrthant(3)
[0.5517241]
The value of the following game can be computed using the fact
- that the identity is invertible:
+ that the identity is invertible::
>>> from cones import NonnegativeOrthant
>>> K = NonnegativeOrthant(3)
"""
Return the dual game to this game.
- EXAMPLES:
+ Examples
+ --------
>>> from cones import NonnegativeOrthant
>>> K = NonnegativeOrthant(3)
[ 1].
"""
- return SymmetricLinearGame(self._L, # It will be transposed in __init__().
- self._K, # Since "K" is symmetric.
+ # We pass ``self._L`` right back into the constructor, because
+ # it will be transposed there. And keep in mind that ``self._K``
+ # is its own dual.
+ return SymmetricLinearGame(self._L,
+ self._K,
self._e2,
self._e1)
# the fudge factor we make up later.
ambient_dim = randint(2, 10)
K = IceCream(ambient_dim)
- e1 = [1]
- e2 = [1]
+ e1 = [1] # Set the "height" of e1 to one
+ e2 = [1] # And the same for e2
+
# If we choose the rest of the components of e1,e2 randomly
# between 0 and 1, then the largest the squared norm of the
# non-height part of e1,e2 could be is the 1*(dim(K) - 1). We