Scippy

SCIP

Solving Constraint Integer Programs

pub_bandit_epsgreedy.h
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4 /* SCIP --- Solving Constraint Integer Programs */
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24 
25 /**@file pub_bandit_epsgreedy.h
26  * @ingroup PublicBanditMethods
27  * @brief public methods for the epsilon greedy bandit selector
28  * @author Gregor Hendel
29  */
30 
31 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32 
33 #ifndef SRC_SCIP_PUB_BANDIT_EPSGREEDY_H_
34 #define SRC_SCIP_PUB_BANDIT_EPSGREEDY_H_
35 
36 
37 #include "scip/def.h"
38 #include "scip/type_scip.h"
39 #include "scip/type_bandit.h"
40 
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 
45 /**@addtogroup PublicBanditMethods
46  *
47  * ## Epsilon greedy
48  *
49  * Epsilon greedy is a randomized algorithm for the multi-armed bandit problem.
50  *
51  * In every iteration, it either
52  * selects an action uniformly at random with
53  * probability \f$ \varepsilon_t\f$
54  * or it greedily exploits the best action seen so far with
55  * probability \f$ 1 - \varepsilon_t \f$.
56  * In this implementation, \f$ \varepsilon_t \f$ decreases over time
57  * (number of selections performed), controlled by the epsilon parameter.
58  *
59  * @{
60  */
61 
62 /** create and resets an epsilon greedy bandit algorithm */
63 SCIP_EXPORT
65  SCIP* scip, /**< SCIP data structure */
66  SCIP_BANDIT** epsgreedy, /**< pointer to store the epsilon greedy bandit algorithm */
67  SCIP_Real* priorities, /**< nonnegative priorities for each action, or NULL if not needed */
68  SCIP_Real eps, /**< parameter to increase probability for exploration between all actions */
69  SCIP_Bool usemodification, /**< TRUE if modified eps greedy should be used */
70  SCIP_Bool preferrecent, /**< should the weights be updated in an exponentially decaying way? */
71  SCIP_Real decayfactor, /**< the factor to reduce the weight of older observations if exponential decay is enabled */
72  int avglim, /**< nonnegative limit on observation number before the exponential decay starts,
73  * only relevant if exponential decay is enabled
74  */
75  int nactions, /**< the number of possible actions */
76  unsigned int initseed /**< initial seed for random number generation */
77  );
78 
79 /** get weights array of epsilon greedy bandit algorithm */
80 SCIP_EXPORT
82  SCIP_BANDIT* epsgreedy /**< epsilon greedy bandit algorithm */
83  );
84 
85 /** set epsilon parameter of epsilon greedy bandit algorithm */
86 SCIP_EXPORT
88  SCIP_BANDIT* epsgreedy, /**< epsilon greedy bandit algorithm */
89  SCIP_Real eps /**< parameter to increase probability for exploration between all actions */
90  );
91 
92 /** @} */
93 
94 
95 
96 #ifdef __cplusplus
97 }
98 #endif
99 
100 #endif
void SCIPsetEpsilonEpsgreedy(SCIP_BANDIT *epsgreedy, SCIP_Real eps)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
real eps
type definitions for SCIP&#39;s main datastructure
type definitions for bandit selection algorithms
#define SCIP_Bool
Definition: def.h:91
SCIP_RETCODE SCIPcreateBanditEpsgreedy(SCIP *scip, SCIP_BANDIT **epsgreedy, SCIP_Real *priorities, SCIP_Real eps, SCIP_Bool usemodification, SCIP_Bool preferrecent, SCIP_Real decayfactor, int avglim, int nactions, unsigned int initseed)
#define SCIP_Real
Definition: def.h:173
SCIP_Real * SCIPgetWeightsEpsgreedy(SCIP_BANDIT *epsgreedy)
common defines and data types used in all packages of SCIP