11 #include "uct/internal.h"
13 #include "uct/policy/generic.h"
15 /* This implements the UCB1 policy with an extra AMAF heuristics. */
17 struct ucb1_policy_amaf
{
18 /* This is what the Modification of UCT with Patterns in Monte Carlo Go
19 * paper calls 'p'. Original UCB has this on 2, but this seems to
20 * produce way too wide searches; reduce this to get deeper and
21 * narrower readouts - try 0.2. */
23 /* First Play Urgency - if set to less than infinity (the MoGo paper
24 * above reports 1.0 as the best), new branches are explored only
25 * if none of the existing ones has higher urgency than fpu. */
31 /* Coefficient of local tree values embedded in RAVE. */
36 static inline float fast_sqrt(int x
)
38 static const float table
[] = {
39 0, 1, 1.41421356237309504880, 1.73205080756887729352,
40 2.00000000000000000000, 2.23606797749978969640,
41 2.44948974278317809819, 2.64575131106459059050,
42 2.82842712474619009760, 3.00000000000000000000,
43 3.16227766016837933199, 3.31662479035539984911,
44 3.46410161513775458705, 3.60555127546398929311,
45 3.74165738677394138558, 3.87298334620741688517,
46 4.00000000000000000000, 4.12310562561766054982,
47 4.24264068711928514640, 4.35889894354067355223,
48 4.47213595499957939281, 4.58257569495584000658,
49 4.69041575982342955456, 4.79583152331271954159,
50 4.89897948556635619639, 5.00000000000000000000,
51 5.09901951359278483002, 5.19615242270663188058,
52 5.29150262212918118100, 5.38516480713450403125,
53 5.47722557505166113456, 5.56776436283002192211,
54 5.65685424949238019520, 5.74456264653802865985,
55 5.83095189484530047087, 5.91607978309961604256,
56 6.00000000000000000000, 6.08276253029821968899,
57 6.16441400296897645025, 6.24499799839839820584,
58 6.32455532033675866399, 6.40312423743284868648,
59 6.48074069840786023096, 6.55743852430200065234,
60 6.63324958071079969822, 6.70820393249936908922,
61 6.78232998312526813906, 6.85565460040104412493,
62 6.92820323027550917410, 7.00000000000000000000,
63 7.07106781186547524400, 7.14142842854284999799,
64 7.21110255092797858623, 7.28010988928051827109,
65 7.34846922834953429459, 7.41619848709566294871,
66 7.48331477354788277116, 7.54983443527074969723,
67 7.61577310586390828566, 7.68114574786860817576,
68 7.74596669241483377035, 7.81024967590665439412,
69 7.87400787401181101968, 7.93725393319377177150,
71 if (x
< sizeof(table
) / sizeof(*table
)) {
78 #define LTREE_DEBUG if (0)
80 ucb1rave_evaluate(struct uct_policy
*p
, struct tree
*tree
, struct uct_descent
*descent
, int parity
)
82 struct ucb1_policy_amaf
*b
= p
->data
;
83 struct tree_node
*node
= descent
->node
;
84 struct tree_node
*lnode
= descent
->lnode
;
86 struct move_stats n
= node
->u
, r
= node
->amaf
;
87 if (p
->uct
->amaf_prior
) {
88 stats_merge(&r
, &node
->prior
);
90 stats_merge(&n
, &node
->prior
);
93 /* Local tree heuristics. */
94 if (p
->uct
->local_tree
&& b
->ltree_rave
> 0 && lnode
) {
95 struct move_stats l
= lnode
->u
;
96 l
.playouts
*= b
->ltree_rave
;
97 LTREE_DEBUG
fprintf(stderr
, "[ltree] adding [%s] %f%%%d to [%s] RAVE %f%%%d\n",
98 coord2sstr(lnode
->coord
, tree
->board
), l
.value
, l
.playouts
,
99 coord2sstr(node
->coord
, tree
->board
), r
.value
, r
.playouts
);
106 /* At the beginning, beta is at 1 and RAVE is used.
107 * At b->equiv_rate, beta is at 1/3 and gets steeper on. */
109 if (b
->sylvain_rave
) {
110 beta
= (float) r
.playouts
/ (r
.playouts
+ n
.playouts
111 + (float) n
.playouts
* r
.playouts
/ b
->equiv_rave
);
113 /* XXX: This can be cached in descend; but we don't use this by default. */
114 beta
= sqrt(b
->equiv_rave
/ (3 * node
->parent
->u
.playouts
+ b
->equiv_rave
));
117 value
= beta
* r
.value
+ (1.f
- beta
) * n
.value
;
121 } else if (r
.playouts
) {
124 descent
->value
.playouts
= r
.playouts
+ n
.playouts
;
125 descent
->value
.value
= value
;
126 return tree_node_get_value(tree
, parity
, value
);
130 ucb1rave_descend(struct uct_policy
*p
, struct tree
*tree
, struct uct_descent
*descent
, int parity
, bool allow_pass
)
132 struct ucb1_policy_amaf
*b
= p
->data
;
134 if (b
->explore_p
> 0)
135 nconf
= sqrt(log(descent
->node
->u
.playouts
+ descent
->node
->prior
.playouts
));
137 uctd_try_node_children(tree
, descent
, allow_pass
, parity
, p
->uct
->tenuki_d
, di
, urgency
) {
138 struct tree_node
*ni
= di
.node
;
139 urgency
= ucb1rave_evaluate(p
, tree
, &di
, parity
);
141 if (ni
->u
.playouts
> 0 && b
->explore_p
> 0) {
142 urgency
+= b
->explore_p
* nconf
/ fast_sqrt(ni
->u
.playouts
);
144 } else if (ni
->u
.playouts
+ ni
->amaf
.playouts
+ ni
->prior
.playouts
== 0) {
145 /* assert(!u->even_eqex); */
148 } uctd_set_best_child(di
, urgency
);
150 uctd_get_best_child(descent
);
155 ucb1amaf_update(struct uct_policy
*p
, struct tree
*tree
, struct tree_node
*node
,
156 enum stone node_color
, enum stone player_color
,
157 struct playout_amafmap
*map
, float result
)
159 struct ucb1_policy_amaf
*b
= p
->data
;
160 enum stone child_color
= stone_other(node_color
);
163 struct board bb
; bb
.size
= 9+2;
164 for (struct tree_node
*ni
= node
; ni
; ni
= ni
->parent
)
165 fprintf(stderr
, "%s ", coord2sstr(ni
->coord
, &bb
));
166 fprintf(stderr
, "[color %d] update result %d (color %d)\n",
167 node_color
, result
, player_color
);
171 if (node
->parent
== NULL
)
172 assert(tree
->root_color
== stone_other(child_color
));
174 stats_add_result(&node
->u
, result
, 1);
175 if (amaf_nakade(map
->map
[node
->coord
]))
176 amaf_op(map
->map
[node
->coord
], -);
178 /* This loop ignores symmetry considerations, but they should
179 * matter only at a point when AMAF doesn't help much. */
180 for (struct tree_node
*ni
= node
->children
; ni
; ni
= ni
->sibling
) {
181 assert(map
->map
[ni
->coord
] != S_OFFBOARD
);
182 if (map
->map
[ni
->coord
] == S_NONE
)
184 assert(map
->game_baselen
>= 0);
185 enum stone amaf_color
= map
->map
[ni
->coord
];
186 if (amaf_nakade(map
->map
[ni
->coord
])) {
187 if (!b
->check_nakade
)
189 /* We don't care to implement both_colors
190 * properly since it sucks anyway. */
192 for (i
= map
->game_baselen
; i
< map
->gamelen
; i
++)
193 if (map
->game
[i
].coord
== ni
->coord
194 && map
->game
[i
].color
== child_color
)
196 if (i
== map
->gamelen
)
198 amaf_color
= child_color
;
202 if (amaf_color
!= child_color
) {
207 /* For child_color != player_color, we still want
208 * to record the result unmodified; in that case,
209 * we will correctly negate them at the descend phase. */
211 stats_add_result(&ni
->amaf
, nres
, 1);
214 struct board bb
; bb
.size
= 9+2;
215 fprintf(stderr
, "* %s<%"PRIhash
"> -> %s<%"PRIhash
"> [%d/%f => %d/%f]\n",
216 coord2sstr(node
->coord
, &bb
), node
->hash
,
217 coord2sstr(ni
->coord
, &bb
), ni
->hash
,
218 player_color
, result
, child_color
, nres
);
222 if (!is_pass(node
->coord
)) {
225 node
= node
->parent
; child_color
= stone_other(child_color
);
231 policy_ucb1amaf_init(struct uct
*u
, char *arg
)
233 struct uct_policy
*p
= calloc2(1, sizeof(*p
));
234 struct ucb1_policy_amaf
*b
= calloc2(1, sizeof(*b
));
237 p
->choose
= uctp_generic_choose
;
238 p
->winner
= uctp_generic_winner
;
239 p
->evaluate
= ucb1rave_evaluate
;
240 p
->descend
= ucb1rave_descend
;
241 p
->update
= ucb1amaf_update
;
242 p
->wants_amaf
= true;
244 b
->explore_p
= 0; // 0.02 can be also good on 19x19 with prior=eqex=40
245 b
->equiv_rave
= 3000;
247 b
->check_nakade
= true;
248 b
->sylvain_rave
= true;
249 b
->ltree_rave
= 1.0f
;
252 char *optspec
, *next
= arg
;
255 next
+= strcspn(next
, ":");
256 if (*next
) { *next
++ = 0; } else { *next
= 0; }
258 char *optname
= optspec
;
259 char *optval
= strchr(optspec
, '=');
260 if (optval
) *optval
++ = 0;
262 if (!strcasecmp(optname
, "explore_p")) {
263 b
->explore_p
= atof(optval
);
264 } else if (!strcasecmp(optname
, "fpu") && optval
) {
265 b
->fpu
= atof(optval
);
266 } else if (!strcasecmp(optname
, "equiv_rave") && optval
) {
267 b
->equiv_rave
= atof(optval
);
268 } else if (!strcasecmp(optname
, "both_colors")) {
269 b
->both_colors
= true;
270 } else if (!strcasecmp(optname
, "sylvain_rave")) {
271 b
->sylvain_rave
= !optval
|| *optval
== '1';
272 } else if (!strcasecmp(optname
, "check_nakade")) {
273 b
->check_nakade
= !optval
|| *optval
== '1';
274 } else if (!strcasecmp(optname
, "ltree_rave") && optval
) {
275 b
->ltree_rave
= atof(optval
);
277 fprintf(stderr
, "ucb1amaf: Invalid policy argument %s or missing value\n",