Implement computing principal branch of agent QRE

gambitproject · Jun 4, 2024 · 575835f · 575835f
1 parent 2c844a0
commit 575835f
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Showing 3 changed files with 36 additions and 3 deletions.
diff --git a/src/pygambit/gambit.pxd b/src/pygambit/gambit.pxd
@@ -395,6 +395,9 @@ cdef extern from "util.h":
     shared_ptr[c_LogitQREMixedStrategyProfile] copyitem_list_qrem "sharedcopyitem"(
             c_List[c_LogitQREMixedStrategyProfile], int
     ) except +
+    shared_ptr[c_LogitQREMixedBehaviorProfile] copyitem_list_qreb "sharedcopyitem"(
+            c_List[c_LogitQREMixedBehaviorProfile], int
+    ) except +
 
 
 cdef extern from "solvers/enumpure/enumpure.h":

diff --git a/src/pygambit/nash.pxi b/src/pygambit/nash.pxi
@@ -264,8 +264,11 @@ def logit_strategy_atlambda(game: Game,
     return ret
 
 
-def logit_principal_branch(game: Game, first_step: float = .03, max_accel: float = 1.1):
-    solns = LogitStrategyPrincipalBranchWrapper(game.game, 1.0e-8, first_step, max_accel)
+def _logit_strategy_branch(game: Game,
+                           maxregret: float,
+                           first_step: float,
+                           max_accel: float):
+    solns = LogitStrategyPrincipalBranchWrapper(game.game, maxregret, first_step, max_accel)
     ret = []
     for i in range(solns.Length()):
         p = LogitQREMixedStrategyProfile()
@@ -342,3 +345,16 @@ def logit_behavior_atlambda(game: Game,
     ret = LogitQREMixedBehaviorProfile()
     ret.thisptr = LogitBehaviorAtLambdaWrapper(game.game, lam, first_step, max_accel)
     return ret
+
+
+def _logit_behavior_branch(game: Game,
+                           maxregret: float,
+                           first_step: float,
+                           max_accel: float):
+    solns = LogitBehaviorPrincipalBranchWrapper(game.game, maxregret, first_step, max_accel)
+    ret = []
+    for i in range(solns.Length()):
+        p = LogitQREMixedBehaviorProfile()
+        p.thisptr = copyitem_list_qreb(solns, i+1)
+        ret.append(p)
+    return ret
diff --git a/src/pygambit/nash.py b/src/pygambit/nash.py
@@ -587,6 +587,20 @@ def logit_solve(
     )
 
 
+def logit_solve_branch(
+        game: libgbt.Game,
+        use_strategic: bool = False,
+        maxregret: float = 1.0e-8,
+        first_step: float = .03,
+        max_accel: float = 1.1,
+):
+    if maxregret <= 0.0:
+        raise ValueError("logit_solve(): maxregret argument must be positive")
+    if not game.is_tree or use_strategic:
+        return libgbt._logit_strategy_branch(game, maxregret, first_step, max_accel)
+    else:
+        return libgbt._logit_behavior_branch(game, maxregret, first_step, max_accel)
+
+
 logit_behavior_atlambda = libgbt.logit_behavior_atlambda
 logit_strategy_atlambda = libgbt.logit_strategy_atlambda
-logit_principal_branch = libgbt.logit_principal_branch