11 #include "uct/internal.h"
14 /* This implements the UCB1 policy with an extra AMAF heuristics. */
16 struct ucb1_policy_amaf
{
17 /* This is what the Modification of UCT with Patterns in Monte Carlo Go
18 * paper calls 'p'. Original UCB has this on 2, but this seems to
19 * produce way too wide searches; reduce this to get deeper and
20 * narrower readouts - try 0.2. */
22 /* First Play Urgency - if set to less than infinity (the MoGo paper
23 * above reports 1.0 as the best), new branches are explored only
24 * if none of the existing ones has higher urgency than fpu. */
26 /* Equivalent experience for prior knowledge. MoGo paper recommends
27 * 50 playouts per source. */
28 int eqex
, even_eqex
, gp_eqex
, policy_eqex
;
29 int urg_randoma
, urg_randomm
;
32 bool rave_prior
, both_colors
;
36 struct tree_node
*ucb1_choose(struct uct_policy
*p
, struct tree_node
*node
, struct board
*b
, enum stone color
);
38 struct tree_node
*ucb1_descend(struct uct_policy
*p
, struct tree
*tree
, struct tree_node
*node
, int parity
, bool allow_pass
);
40 void ucb1_prior(struct uct_policy
*p
, struct tree
*tree
, struct tree_node
*node
, struct board
*b
, enum stone color
, int parity
);
43 /* Original RAVE function */
45 ucb1orave_descend(struct uct_policy
*p
, struct tree
*tree
, struct tree_node
*node
, int parity
, bool allow_pass
)
47 /* We want to count in the prior stats here after all. Otherwise,
48 * nodes with positive prior will get explored _LESS_ since the
49 * urgency will be always higher; even with normal FPU because
50 * of the explore coefficient. */
52 struct ucb1_policy_amaf
*b
= p
->data
;
53 float xpl
= log(node
->u
.playouts
+ node
->prior
.playouts
) * b
->explore_p
;
54 float xpl_rave
= log(node
->amaf
.playouts
+ (b
->rave_prior
? node
->prior
.playouts
: 0)) * b
->explore_p_rave
;
55 float beta
= sqrt((float)b
->equiv_rave
/ (3 * (node
->u
.playouts
+ node
->prior
.playouts
) + b
->equiv_rave
));
57 struct tree_node
*nbest
= node
->children
;
58 float best_urgency
= -9999;
59 for (struct tree_node
*ni
= node
->children
; ni
; ni
= ni
->sibling
) {
60 /* Do not consider passing early. */
61 if (likely(!allow_pass
) && unlikely(is_pass(ni
->coord
)))
63 int amaf_wins
= ni
->amaf
.wins
+ (b
->rave_prior
? ni
->prior
.wins
: 0);
64 int amaf_playouts
= ni
->amaf
.playouts
+ (b
->rave_prior
? ni
->prior
.playouts
: 0);
65 int uct_playouts
= ni
->u
.playouts
+ ni
->prior
.playouts
;
66 ni
->amaf
.value
= (float)amaf_wins
/ amaf_playouts
;
67 ni
->prior
.value
= (float)ni
->prior
.wins
/ ni
->prior
.playouts
;
68 float uctp
= (parity
> 0 ? ni
->u
.value
: 1 - ni
->u
.value
) + sqrt(xpl
/ uct_playouts
);
69 float ravep
= (parity
> 0 ? ni
->amaf
.value
: 1 - ni
->amaf
.value
) + sqrt(xpl_rave
/ amaf_playouts
);
70 float urgency
= ni
->u
.playouts
? beta
* ravep
+ (1 - beta
) * uctp
: b
->fpu
;
71 // fprintf(stderr, "uctp %f (uct %d/%d) ravep %f (xpl %f amaf %d/%d) beta %f => %f\n", uctp, ni->u.wins, ni->u.playouts, ravep, xpl_rave, amaf_wins, amaf_playouts, beta, urgency);
73 urgency
+= (float)(fast_random(b
->urg_randoma
) - b
->urg_randoma
/ 2) / 1000;
75 urgency
*= (float)(fast_random(b
->urg_randomm
) + 5) / b
->urg_randomm
;
76 if (urgency
> best_urgency
) {
77 best_urgency
= urgency
;
84 float fast_sqrt(int x
)
86 static const float table
[] = {
89 1.41421356237309504880,
90 1.73205080756887729352,
91 2.00000000000000000000,
93 2.23606797749978969640,
94 2.44948974278317809819,
95 2.64575131106459059050,
96 2.82842712474619009760,
97 3.00000000000000000000,
98 3.16227766016837933199,
99 3.31662479035539984911,
100 3.46410161513775458705,
101 3.60555127546398929311,
102 3.74165738677394138558,
103 3.87298334620741688517,
104 4.00000000000000000000,
105 4.12310562561766054982,
106 4.24264068711928514640,
107 4.35889894354067355223,
108 4.47213595499957939281,
109 4.58257569495584000658,
110 4.69041575982342955456,
111 4.79583152331271954159,
112 4.89897948556635619639,
113 5.00000000000000000000,
114 5.09901951359278483002,
115 5.19615242270663188058,
116 5.29150262212918118100,
117 5.38516480713450403125,
118 5.47722557505166113456,
119 5.56776436283002192211,
120 5.65685424949238019520,
121 5.74456264653802865985,
122 5.83095189484530047087,
123 5.91607978309961604256,
124 6.00000000000000000000,
125 6.08276253029821968899,
126 6.16441400296897645025,
127 6.24499799839839820584,
128 6.32455532033675866399,
129 6.40312423743284868648,
130 6.48074069840786023096,
131 6.55743852430200065234,
132 6.63324958071079969822,
133 6.70820393249936908922,
134 6.78232998312526813906,
135 6.85565460040104412493,
136 6.92820323027550917410,
137 7.00000000000000000000,
138 7.07106781186547524400,
139 7.14142842854284999799,
140 7.21110255092797858623,
141 7.28010988928051827109,
142 7.34846922834953429459,
143 7.41619848709566294871,
144 7.48331477354788277116,
145 7.54983443527074969723,
146 7.61577310586390828566,
147 7.68114574786860817576,
148 7.74596669241483377035,
149 7.81024967590665439412,
150 7.87400787401181101968,
151 7.93725393319377177150,
154 //printf("sqrt %d\n", x);
155 if (x
< sizeof(table
) / sizeof(*table
)) {
161 int base
= 1 << (sizeof(int) * 8 - 2);
162 if ((x
& 0xFFFF0000) == 0) base
>>= 16;
163 if ((x
& 0xFF00FF00) == 0) base
>>= 8;
164 if ((x
& 0xF0F0F0F0) == 0) base
>>= 4;
165 if ((x
& 0xCCCCCCCC) == 0) base
>>= 2;
166 // "base" starts at the highest power of four <= the argument.
176 printf("sqrt %d = %d\n", x
, y
);
182 /* Sylvain RAVE function */
184 ucb1srave_descend(struct uct_policy
*p
, struct tree
*tree
, struct tree_node
*node
, int parity
, bool allow_pass
)
186 struct ucb1_policy_amaf
*b
= p
->data
;
187 float rave_coef
= 1.0f
/ b
->equiv_rave
;
189 if (b
->explore_p
> 0 || b
->explore_p_rave
> 0)
190 conf
= sqrt(log(node
->u
.playouts
+ node
->prior
.playouts
));
192 // XXX: Stack overflow danger on big boards?
193 struct tree_node
*nbest
[256] = { node
->children
}; int nbests
= 1;
194 float best_urgency
= -9999;
196 for (struct tree_node
*ni
= node
->children
; ni
; ni
= ni
->sibling
) {
197 /* Do not consider passing early. */
198 if (likely(!allow_pass
) && unlikely(is_pass(ni
->coord
)))
201 /* TODO: Exploration? */
203 int ngames
= ni
->u
.playouts
;
204 int nwins
= ni
->u
.wins
;
205 int rgames
= ni
->amaf
.playouts
;
206 int rwins
= ni
->amaf
.wins
;
208 rgames
+= ni
->prior
.playouts
;
209 rwins
+= ni
->prior
.wins
;
211 ngames
+= ni
->prior
.playouts
;
212 nwins
+= ni
->prior
.wins
;
215 nwins
= ngames
- nwins
;
216 rwins
= rgames
- rwins
;
218 float nval
= 0, rval
= 0;
220 nval
= (float) nwins
/ ngames
;
221 if (b
->explore_p
> 0)
222 nval
+= b
->explore_p
* conf
/ fast_sqrt(ngames
);
225 rval
= (float) rwins
/ rgames
;
226 if (b
->explore_p_rave
> 0)
227 rval
+= b
->explore_p_rave
* conf
/ fast_sqrt(rgames
);
230 /* XXX: We later compare urgency with best_urgency; this can
231 * be difficult given that urgency can be in register with
232 * higher precision than best_urgency, thus even though
233 * the numbers are in fact the same, urgency will be
234 * slightly higher (or lower). Thus, we declare urgency
235 * as volatile, attempting to force the compiler to keep
236 * everything as a float. Ideally, we should do some random
237 * __FLT_EPSILON__ magic instead. */
238 volatile float urgency
;
241 /* At the beginning, beta is at 1 and RAVE is used.
242 * At b->equiv_rate, beta is at 1/3 and gets steeper on. */
243 float beta
= (float) rgames
/ (rgames
+ ngames
+ rave_coef
* ngames
* rgames
);
245 //if (node->coord == 7*11+4) // D7
246 fprintf(stderr
, "[beta %f = %d / (%d + %d + %f)]\n",
247 beta
, rgames
, rgames
, ngames
, rave_coef
* ngames
* rgames
);
249 urgency
= beta
* rval
+ (1 - beta
) * nval
;
256 assert(!b
->even_eqex
);
261 struct board bb
; bb
.size
= 11;
262 //if (node->coord == 7*11+4) // D7
263 fprintf(stderr
, "%s<%lld>-%s<%lld> urgency %f (r %d / %d, n %d / %d)\n",
264 coord2sstr(ni
->parent
->coord
, &bb
), ni
->parent
->hash
,
265 coord2sstr(ni
->coord
, &bb
), ni
->hash
, urgency
,
266 rwins
, rgames
, nwins
, ngames
);
269 urgency
+= (float)(fast_random(b
->urg_randoma
) - b
->urg_randoma
/ 2) / 1000;
271 urgency
*= (float)(fast_random(b
->urg_randomm
) + 5) / b
->urg_randomm
;
273 if (urgency
> best_urgency
)
274 best_urgency
= urgency
; nbests
= 0;
275 if (urgency
>= best_urgency
)
276 nbest
[nbests
++] = ni
;
279 struct board bb
; bb
.size
= 11;
280 fprintf(stderr
, "[%s %d: ", coord2sstr(node
->coord
, &bb
), nbests
);
281 for (int zz
= 0; zz
< nbests
; zz
++)
282 fprintf(stderr
, "%s", coord2sstr(nbest
[zz
]->coord
, &bb
));
283 fprintf(stderr
, "]\n");
285 return nbest
[fast_random(nbests
)];
289 update_node(struct uct_policy
*p
, struct tree_node
*node
, int result
)
292 node
->u
.wins
+= result
;
293 tree_update_node_value(node
);
296 update_node_amaf(struct uct_policy
*p
, struct tree_node
*node
, int result
)
298 node
->amaf
.playouts
++;
299 node
->amaf
.wins
+= result
;
300 tree_update_node_value(node
);
304 ucb1amaf_update(struct uct_policy
*p
, struct tree
*tree
, struct tree_node
*node
, enum stone node_color
, enum stone player_color
, struct playout_amafmap
*map
, int result
)
306 struct ucb1_policy_amaf
*b
= p
->data
;
307 enum stone child_color
= stone_other(node_color
);
310 struct board bb
; bb
.size
= 9+2;
311 for (struct tree_node
*ni
= node
; ni
; ni
= ni
->parent
)
312 fprintf(stderr
, "%s ", coord2sstr(ni
->coord
, &bb
));
313 fprintf(stderr
, "[color %d] update result %d (color %d)\n",
314 node_color
, result
, player_color
);
318 if (p
->descend
!= ucb1_descend
)
319 node
->hints
|= NODE_HINT_NOAMAF
; /* Rave, different update function */
320 update_node(p
, node
, result
);
321 if (amaf_nakade(map
->map
[node
->coord
]))
322 amaf_op(map
->map
[node
->coord
], -);
324 /* This loop ignores symmetry considerations, but they should
325 * matter only at a point when AMAF doesn't help much. */
326 for (struct tree_node
*ni
= node
->children
; ni
; ni
= ni
->sibling
) {
327 assert(map
->map
[ni
->coord
] != S_OFFBOARD
);
328 if (map
->map
[ni
->coord
] == S_NONE
329 || amaf_nakade(map
->map
[ni
->coord
]))
333 if (map
->map
[ni
->coord
] != child_color
) {
338 /* For child_color != player_color, we still want
339 * to record the result unmodified; in that case,
340 * we will correctly negate them at the descend phase. */
342 if (p
->descend
!= ucb1_descend
)
343 ni
->hints
|= NODE_HINT_NOAMAF
; /* Rave, different update function */
344 update_node_amaf(p
, ni
, nres
);
347 fprintf(stderr
, "* %s<%lld> -> %s<%lld> [%d %d => %d/%d]\n", coord2sstr(node
->coord
, &bb
), node
->hash
, coord2sstr(ni
->coord
, &bb
), ni
->hash
, player_color
, child_color
, result
);
351 node
= node
->parent
; child_color
= stone_other(child_color
);
357 policy_ucb1amaf_init(struct uct
*u
, char *arg
)
359 struct uct_policy
*p
= calloc(1, sizeof(*p
));
360 struct ucb1_policy_amaf
*b
= calloc(1, sizeof(*b
));
363 p
->descend
= ucb1srave_descend
;
364 p
->choose
= ucb1_choose
;
365 p
->update
= ucb1amaf_update
;
366 p
->wants_amaf
= true;
368 // RAVE: 0.2vs0: 40% (+-7.3) 0.1vs0: 54.7% (+-3.5)
370 b
->explore_p_rave
= -1;
371 b
->equiv_rave
= 3000;
373 // gp: 14 vs 0: 44% (+-3.5)
375 b
->even_eqex
= b
->policy_eqex
= -1;
379 char *optspec
, *next
= arg
;
382 next
+= strcspn(next
, ":");
383 if (*next
) { *next
++ = 0; } else { *next
= 0; }
385 char *optname
= optspec
;
386 char *optval
= strchr(optspec
, '=');
387 if (optval
) *optval
++ = 0;
389 if (!strcasecmp(optname
, "explore_p")) {
390 b
->explore_p
= atof(optval
);
391 } else if (!strcasecmp(optname
, "prior")) {
393 b
->eqex
= atoi(optval
);
394 } else if (!strcasecmp(optname
, "prior_even") && optval
) {
395 b
->even_eqex
= atoi(optval
);
396 } else if (!strcasecmp(optname
, "prior_gp") && optval
) {
397 b
->gp_eqex
= atoi(optval
);
398 } else if (!strcasecmp(optname
, "prior_policy") && optval
) {
399 b
->policy_eqex
= atoi(optval
);
400 } else if (!strcasecmp(optname
, "fpu") && optval
) {
401 b
->fpu
= atof(optval
);
402 } else if (!strcasecmp(optname
, "urg_randoma") && optval
) {
403 b
->urg_randoma
= atoi(optval
);
404 } else if (!strcasecmp(optname
, "urg_randomm") && optval
) {
405 b
->urg_randomm
= atoi(optval
);
406 } else if (!strcasecmp(optname
, "rave")) {
407 if (optval
&& *optval
== '0')
408 p
->descend
= ucb1_descend
;
409 else if (optval
&& *optval
== 'o')
410 p
->descend
= ucb1orave_descend
;
411 else if (optval
&& *optval
== 's')
412 p
->descend
= ucb1srave_descend
;
413 } else if (!strcasecmp(optname
, "explore_p_rave") && optval
) {
414 b
->explore_p_rave
= atof(optval
);
415 } else if (!strcasecmp(optname
, "equiv_rave") && optval
) {
416 b
->equiv_rave
= atof(optval
);
417 } else if (!strcasecmp(optname
, "rave_prior")) {
419 b
->rave_prior
= true;
420 } else if (!strcasecmp(optname
, "both_colors")) {
421 b
->both_colors
= true;
423 fprintf(stderr
, "ucb1: Invalid policy argument %s or missing value\n", optname
);
428 if (b
->eqex
) p
->prior
= ucb1_prior
;
429 if (b
->even_eqex
< 0) b
->even_eqex
= b
->eqex
;
430 if (b
->gp_eqex
< 0) b
->gp_eqex
= b
->eqex
;
431 if (b
->policy_eqex
< 0) b
->policy_eqex
= b
->eqex
;
432 if (b
->explore_p_rave
< 0) b
->explore_p_rave
= b
->explore_p
;