uct/dynkomi.c

   1 #define DEBUG
   2 #include <assert.h>
   3 #include <math.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "board.h"
   9 #include "debug.h"
  10 #include "tactics/util.h"
  11 #include "uct/dynkomi.h"
  12 #include "uct/internal.h"
  13 #include "uct/tree.h"
  14
  15
  16 static void
  17 generic_done(struct uct_dynkomi *d)
  18 {
  19         if (d->data) free(d->data);
  20         free(d);
  21 }
  22
  23
  24 /* NONE dynkomi strategy - never fiddle with komi values. */
  25
  26 struct uct_dynkomi *
  27 uct_dynkomi_init_none(struct uct *u, char *arg, struct board *b)
  28 {
  29         struct uct_dynkomi *d = calloc2(1, sizeof(*d));
  30         d->uct = u;
  31         d->permove = NULL;
  32         d->persim = NULL;
  33         d->done = generic_done;
  34         d->data = NULL;
  35
  36         if (arg) {
  37                 fprintf(stderr, "uct: Dynkomi method none accepts no arguments\n");
  38                 exit(1);
  39         }
  40
  41         return d;
  42 }
  43
  44
  45 /* LINEAR dynkomi strategy - Linearly Decreasing Handicap Compensation. */
  46 /* At move 0, we impose extra komi of handicap_count*handicap_value, then
  47  * we linearly decrease this extra komi throughout the game down to 0
  48  * at @moves moves. Towards the end of the game the linear compensation
  49  * becomes zero but we increase the extra komi when winning big. This reduces
  50  * the number of point-wasting moves and makes the game more enjoyable for humans. */
  51
  52 struct dynkomi_linear {
  53         int handicap_value[S_MAX];
  54         int moves[S_MAX];
  55         bool rootbased;
  56         /* Increase the extra komi if my win ratio  > green_zone but always
  57          * keep extra_komi <= komi_ratchet. komi_ratchet starts infinite but decreases
  58          * when we give too much extra komi and this puts us back < orange_zone.
  59          * This is meant only to increase the territory margin when playing against
  60          * weaker opponents. We never take negative komi when losing. The ratchet helps
  61          * avoiding oscillations and keeping us above orange_zone.
  62          * To disable the adaptive phase, set green_zone=2. */
  63         floating_t komi_ratchet;
  64         floating_t green_zone;
  65         floating_t orange_zone;
  66         floating_t drop_step;
  67 };
  68
  69 static floating_t
  70 linear_permove(struct uct_dynkomi *d, struct board *b, struct tree *tree)
  71 {
  72         struct dynkomi_linear *l = d->data;
  73         enum stone color = d->uct->pondering ? tree->root_color : stone_other(tree->root_color);
  74         int lmoves = l->moves[color];
  75         floating_t extra_komi;
  76
  77         if (b->moves < lmoves) {
  78                 floating_t base_komi = board_effective_handicap(b, l->handicap_value[color]);
  79                 extra_komi = base_komi * (lmoves - b->moves) / lmoves;
  80         } else {
  81                 extra_komi = 0;
  82         }
  83
  84         /* Do not adjust values in the game beginning. */
  85         if (b->moves < lmoves) return extra_komi;
  86
  87         /* Do not take decisions on unstable value. */
  88         if (tree->root->u.playouts < GJ_MINGAMES) return extra_komi;
  89
  90         floating_t my_value = tree_node_get_value(tree, 1, tree->root->u.value);
  91         /*  We normalize komi as in komi_by_value(), > 0 when winning. */
  92         extra_komi = komi_by_color(extra_komi, color);
  93         assert(extra_komi >= 0);
  94
  95         if (my_value < 0.5 && l->komi_ratchet > 0 && l->komi_ratchet != INFINITY) {
  96                 if (DEBUGL(0))
  97                         fprintf(stderr, "losing %f extra %.1f ratchet %.1f -> 0\n",
  98                                 my_value, extra_komi, l->komi_ratchet);
  99                 /* Disable dynkomi completely, too dangerous in this game. */
 100                 extra_komi = l->komi_ratchet = 0;
 101
 102         } else if (my_value < l->orange_zone && extra_komi > 0) {
 103                 extra_komi = l->komi_ratchet  = fmax(extra_komi - l->drop_step, 0.0);
 104                 if (DEBUGL(3))
 105                         fprintf(stderr, "dropping to %f ratchet -> %.1f\n",
 106                                 my_value, extra_komi);
 107
 108         } else if (my_value > l->green_zone && extra_komi +1 <= l->komi_ratchet) {
 109                 extra_komi += 1;
 110                 if (DEBUGL(3))
 111                         fprintf(stderr, "winning %f extra_komi -> %.1f, ratchet %.1f\n",
 112                                 my_value, extra_komi, l->komi_ratchet);
 113         }
 114         return komi_by_color(extra_komi, color);
 115 }
 116
 117 static floating_t
 118 linear_persim(struct uct_dynkomi *d, struct board *b, struct tree *tree, struct tree_node *node)
 119 {
 120         struct dynkomi_linear *l = d->data;
 121         if (l->rootbased)
 122                 return tree->extra_komi;
 123         /* We don't reuse computed value from tree->extra_komi,
 124          * since we want to use value correct for this node depth.
 125          * This also means the values will stay correct after
 126          * node promotion. */
 127         return linear_permove(d, b, tree);
 128 }
 129
 130 struct uct_dynkomi *
 131 uct_dynkomi_init_linear(struct uct *u, char *arg, struct board *b)
 132 {
 133         struct uct_dynkomi *d = calloc2(1, sizeof(*d));
 134         d->uct = u;
 135         d->permove = linear_permove;
 136         d->persim = linear_persim;
 137         d->done = generic_done;
 138
 139         struct dynkomi_linear *l = calloc2(1, sizeof(*l));
 140         d->data = l;
 141
 142         /* Force white to feel behind and try harder, but not to the
 143          * point of resigning immediately in high handicap games.
 144          * By move 100 white should still be behind but should have
 145          * caught up enough to avoid resigning. */
 146         if (board_large(b)) {
 147                 l->moves[S_BLACK] = 100;
 148                 l->moves[S_WHITE] = 50;
 149         }
 150         /* The real value of one stone is twice the komi so about 15 points.
 151          * But use a lower value to avoid being too pessimistic as black
 152          * or too optimistic as white. */
 153         l->handicap_value[S_BLACK] = 8;
 154         l->handicap_value[S_WHITE] = 1;
 155
 156         l->komi_ratchet = INFINITY;
 157         l->green_zone = 0.85;
 158         l->orange_zone = 0.8;
 159         l->drop_step = 4.0;
 160
 161         if (arg) {
 162                 char *optspec, *next = arg;
 163                 while (*next) {
 164                         optspec = next;
 165                         next += strcspn(next, ":");
 166                         if (*next) { *next++ = 0; } else { *next = 0; }
 167
 168                         char *optname = optspec;
 169                         char *optval = strchr(optspec, '=');
 170                         if (optval) *optval++ = 0;
 171
 172                         if (!strcasecmp(optname, "moves") && optval) {
 173                                 /* Dynamic komi in handicap game; linearly
 174                                  * decreases to basic settings until move
 175                                  * #optval. moves=blackmoves%whitemoves */
 176                                 for (int i = S_BLACK; *optval && i <= S_WHITE; i++) {
 177                                         l->moves[i] = atoi(optval);
 178                                         optval += strcspn(optval, "%");
 179                                         if (*optval) optval++;
 180                                 }
 181                         } else if (!strcasecmp(optname, "handicap_value") && optval) {
 182                                 /* Point value of single handicap stone,
 183                                  * for dynkomi computation. */
 184                                 for (int i = S_BLACK; *optval && i <= S_WHITE; i++) {
 185                                         l->handicap_value[i] = atoi(optval);
 186                                         optval += strcspn(optval, "%");
 187                                         if (*optval) optval++;
 188                                 }
 189                         } else if (!strcasecmp(optname, "rootbased")) {
 190                                 /* If set, the extra komi applied will be
 191                                  * the same for all simulations within a move,
 192                                  * instead of being same for all simulations
 193                                  * within the tree node. */
 194                                 l->rootbased = !optval || atoi(optval);
 195                         } else if (!strcasecmp(optname, "green_zone") && optval) {
 196                                 /* Increase komi when win ratio is above green_zone */
 197                                 l->green_zone = atof(optval);
 198                         } else if (!strcasecmp(optname, "orange_zone") && optval) {
 199                                 /* Decrease komi when > 0 and win ratio is below orange_zone */
 200                                 l->orange_zone = atof(optval);
 201                         } else if (!strcasecmp(optname, "drop_step") && optval) {
 202                                 /* Decrease komi by drop_step points */
 203                                 l->drop_step = atof(optval);
 204                         } else {
 205                                 fprintf(stderr, "uct: Invalid dynkomi argument %s or missing value\n", optname);
 206                                 exit(1);
 207                         }
 208                 }
 209         }
 210
 211         return d;
 212 }
 213
 214
 215 /* ADAPTIVE dynkomi strategy - Adaptive Situational Compensation */
 216 /* We adapt the komi based on current situation:
 217  * (i) score-based: We maintain the average score outcome of our
 218  * games and adjust the komi by a fractional step towards the expected
 219  * score;
 220  * (ii) value-based: While winrate is above given threshold, adjust
 221  * the komi by a fixed step in the appropriate direction.
 222  * These adjustments can be
 223  * (a) Move-stepped, new extra komi value is always set only at the
 224  * beginning of the tree search for next move;
 225  * (b) Continuous, new extra komi value is periodically re-determined
 226  * and adjusted throughout a single tree search. */
 227
 228 struct dynkomi_adaptive {
 229         /* Do not take measured average score into regard for
 230          * first @lead_moves - the variance is just too much.
 231          * (Instead, we consider the handicap-based komi provided
 232          * by linear dynkomi.) */
 233         int lead_moves;
 234         /* Maximum komi to pretend the opponent to give. */
 235         floating_t max_losing_komi;
 236         /* Game portion at which losing komi is not allowed anymore. */
 237         floating_t losing_komi_stop;
 238         /* Alternative game portion determination. */
 239         bool adapt_aport;
 240         floating_t (*indicator)(struct uct_dynkomi *d, struct board *b, struct tree *tree, enum stone color);
 241
 242         /* Value-based adaptation. */
 243         floating_t zone_red, zone_green;
 244         int score_step;
 245         floating_t score_step_byavg; // use portion of average score as increment
 246         bool use_komi_ratchet;
 247         bool losing_komi_ratchet; // ratchet even losing komi
 248         int komi_ratchet_maxage;
 249         // runtime, not configuration:
 250         int komi_ratchet_age;
 251         floating_t komi_ratchet;
 252
 253         /* Score-based adaptation. */
 254         floating_t (*adapter)(struct uct_dynkomi *d, struct board *b);
 255         floating_t adapt_base; // [0,1)
 256         /* Sigmoid adaptation rate parameter; see below for details. */
 257         floating_t adapt_phase; // [0,1]
 258         floating_t adapt_rate; // [1,infty)
 259         /* Linear adaptation rate parameter. */
 260         int adapt_moves;
 261         floating_t adapt_dir; // [-1,1]
 262 };
 263 #define TRUSTWORTHY_KOMI_PLAYOUTS 200
 264
 265 static floating_t
 266 board_game_portion(struct dynkomi_adaptive *a, struct board *b)
 267 {
 268         if (!a->adapt_aport) {
 269                 int total_moves = b->moves + 2 * board_estimated_moves_left(b);
 270                 return (floating_t) b->moves / total_moves;
 271         } else {
 272                 int brsize = board_size(b) - 2;
 273                 return 1.0 - (floating_t) b->flen / (brsize * brsize);
 274         }
 275 }
 276
 277 static floating_t
 278 adapter_sigmoid(struct uct_dynkomi *d, struct board *b)
 279 {
 280         struct dynkomi_adaptive *a = d->data;
 281         /* Figure out how much to adjust the komi based on the game
 282          * stage. The adaptation rate is 0 at the beginning,
 283          * at game stage a->adapt_phase crosses though 0.5 and
 284          * approaches 1 at the game end; the slope is controlled
 285          * by a->adapt_rate. */
 286         floating_t game_portion = board_game_portion(a, b);
 287         floating_t l = game_portion - a->adapt_phase;
 288         return 1.0 / (1.0 + exp(-a->adapt_rate * l));
 289 }
 290
 291 static floating_t
 292 adapter_linear(struct uct_dynkomi *d, struct board *b)
 293 {
 294         struct dynkomi_adaptive *a = d->data;
 295         /* Figure out how much to adjust the komi based on the game
 296          * stage. We just linearly increase/decrease the adaptation
 297          * rate for first N moves. */
 298         if (b->moves > a->adapt_moves)
 299                 return 0;
 300         if (a->adapt_dir < 0)
 301                 return 1 - (- a->adapt_dir) * b->moves / a->adapt_moves;
 302         else
 303                 return a->adapt_dir * b->moves / a->adapt_moves;
 304 }
 305
 306 static floating_t
 307 komi_by_score(struct uct_dynkomi *d, struct board *b, struct tree *tree, enum stone color)
 308 {
 309         struct dynkomi_adaptive *a = d->data;
 310         if (d->score.playouts < TRUSTWORTHY_KOMI_PLAYOUTS)
 311                 return tree->extra_komi;
 312
 313         struct move_stats score = d->score;
 314         /* Almost-reset tree->score to gather fresh stats. */
 315         d->score.playouts = 1;
 316
 317         /* Look at average score and push extra_komi in that direction. */
 318         floating_t p = a->adapter(d, b);
 319         p = a->adapt_base + p * (1 - a->adapt_base);
 320         if (p > 0.9) p = 0.9; // don't get too eager!
 321         floating_t extra_komi = tree->extra_komi + p * score.value;
 322         if (DEBUGL(3))
 323                 fprintf(stderr, "mC += %f * %f\n", p, score.value);
 324         return extra_komi;
 325 }
 326
 327 static floating_t
 328 komi_by_value(struct uct_dynkomi *d, struct board *b, struct tree *tree, enum stone color)
 329 {
 330         struct dynkomi_adaptive *a = d->data;
 331         if (d->value.playouts < TRUSTWORTHY_KOMI_PLAYOUTS)
 332                 return tree->extra_komi;
 333
 334         struct move_stats value = d->value;
 335         /* Almost-reset tree->value to gather fresh stats. */
 336         d->value.playouts = 1;
 337         /* Correct color POV. */
 338         if (color == S_WHITE)
 339                 value.value = 1 - value.value;
 340
 341         /* We have three "value zones":
 342          * red zone | yellow zone | green zone
 343          *        ~45%           ~60%
 344          * red zone: reduce komi
 345          * yellow zone: do not touch komi
 346          * green zone: enlage komi.
 347          *
 348          * Also, at some point komi will be tuned in such way
 349          * that it will be in green zone but increasing it will
 350          * be unfeasible. Thus, we have a _ratchet_ - we will
 351          * remember the last komi that has put us into the
 352          * red zone, and not use it or go over it. We use the
 353          * ratchet only when giving extra komi, we always want
 354          * to try to reduce extra komi we take.
 355          *
 356          * TODO: Make the ratchet expire after a while. */
 357
 358         /* We use komi_by_color() first to normalize komi
 359          * additions/subtractions, then apply it again on
 360          * return value to restore original komi parity. */
 361         /* Positive extra_komi means that we are _giving_
 362          * komi (winning), negative extra_komi is _taking_
 363          * komi (losing). */
 364         floating_t extra_komi = komi_by_color(tree->extra_komi, color);
 365         int score_step_red = -a->score_step;
 366         int score_step_green = a->score_step;
 367
 368         if (a->score_step_byavg != 0) {
 369                 struct move_stats score = d->score;
 370                 /* Almost-reset tree->score to gather fresh stats. */
 371                 d->score.playouts = 1;
 372                 /* Correct color POV. */
 373                 if (color == S_WHITE)
 374                         score.value = - score.value;
 375                 if (score.value > 0)
 376                         score_step_green = round(score.value * a->score_step_byavg);
 377                 else
 378                         score_step_red = round(-score.value * a->score_step_byavg);
 379                 if (score_step_green < 0 || score_step_red > 0) {
 380                         /* The steps are in bad direction - keep still. */
 381                         return komi_by_color(extra_komi, color);
 382                 }
 383         }
 384
 385         /* Wear out the ratchet. */
 386         if (a->use_komi_ratchet && a->komi_ratchet_maxage > 0) {
 387                 a->komi_ratchet_age += value.playouts;
 388                 if (a->komi_ratchet_age > a->komi_ratchet_maxage) {
 389                         a->komi_ratchet = 1000;
 390                         a->komi_ratchet_age = 0;
 391                 }
 392         }
 393
 394         if (value.value < a->zone_red) {
 395                 /* Red zone. Take extra komi. */
 396                 if (DEBUGL(3))
 397                         fprintf(stderr, "[red] %f, step %d | komi ratchet %f age %d/%d -> %f\n",
 398                                 value.value, score_step_red, a->komi_ratchet, a->komi_ratchet_age, a->komi_ratchet_maxage, extra_komi);
 399                 if (a->losing_komi_ratchet || extra_komi > 0) {
 400                         a->komi_ratchet = extra_komi;
 401                         a->komi_ratchet_age = 0;
 402                 }
 403                 extra_komi += score_step_red;
 404                 return komi_by_color(extra_komi, color);
 405
 406         } else if (value.value < a->zone_green) {
 407                 /* Yellow zone, do nothing. */
 408                 return komi_by_color(extra_komi, color);
 409
 410         } else {
 411                 /* Green zone. Give extra komi. */
 412                 if (DEBUGL(3))
 413                         fprintf(stderr, "[green] %f, step %d | komi ratchet %f age %d/%d\n",
 414                                 value.value, score_step_green, a->komi_ratchet, a->komi_ratchet_age, a->komi_ratchet_maxage);
 415                 extra_komi += score_step_green;
 416                 if (a->use_komi_ratchet && extra_komi >= a->komi_ratchet)
 417                         extra_komi = a->komi_ratchet - 1;
 418                 return komi_by_color(extra_komi, color);
 419         }
 420 }
 421
 422 static floating_t
 423 bounded_komi(struct dynkomi_adaptive *a, struct board *b,
 424              enum stone color, floating_t komi, floating_t max_losing_komi)
 425 {
 426         /* At the end of game, disallow losing komi. */
 427         if (komi_by_color(komi, color) < 0
 428             && board_game_portion(a, b) > a->losing_komi_stop)
 429                 return 0;
 430
 431         /* Get lower bound on komi we take so that we don't underperform
 432          * too much. */
 433         floating_t min_komi = komi_by_color(- max_losing_komi, color);
 434
 435         if (komi_by_color(komi - min_komi, color) > 0)
 436                 return komi;
 437         else
 438                 return min_komi;
 439 }
 440
 441 static floating_t
 442 adaptive_permove(struct uct_dynkomi *d, struct board *b, struct tree *tree)
 443 {
 444         /* We do not use extra komi at the game end - we are not
 445          * to fool ourselves at this point. */
 446         if (board_estimated_moves_left(b) <= MIN_MOVES_LEFT) {
 447                 tree->use_extra_komi = false;
 448                 return 0;
 449         }
 450         struct dynkomi_adaptive *a = d->data;
 451         enum stone color = stone_other(tree->root_color);
 452         if (DEBUGL(3))
 453                 fprintf(stderr, "m %d/%d ekomi %f permove %f/%d\n",
 454                         b->moves, a->lead_moves, tree->extra_komi,
 455                         d->score.value, d->score.playouts);
 456
 457         if (b->moves <= a->lead_moves)
 458                 return bounded_komi(a, b, color,
 459                                     board_effective_handicap(b, 7 /* XXX */),
 460                                     a->max_losing_komi);
 461
 462         floating_t komi = a->indicator(d, b, tree, color);
 463         if (DEBUGL(3))
 464                 fprintf(stderr, "dynkomi: %f -> %f\n", tree->extra_komi, komi);
 465         return bounded_komi(a, b, color, komi, a->max_losing_komi);
 466 }
 467
 468 static floating_t
 469 adaptive_persim(struct uct_dynkomi *d, struct board *b, struct tree *tree, struct tree_node *node)
 470 {
 471         return tree->extra_komi;
 472 }
 473
 474 struct uct_dynkomi *
 475 uct_dynkomi_init_adaptive(struct uct *u, char *arg, struct board *b)
 476 {
 477         struct uct_dynkomi *d = calloc2(1, sizeof(*d));
 478         d->uct = u;
 479         d->permove = adaptive_permove;
 480         d->persim = adaptive_persim;
 481         d->done = generic_done;
 482
 483         struct dynkomi_adaptive *a = calloc2(1, sizeof(*a));
 484         d->data = a;
 485
 486         a->lead_moves = board_large(b) ? 20 : 4; // XXX
 487         a->max_losing_komi = 30;
 488         a->losing_komi_stop = 1.0f;
 489         a->indicator = komi_by_value;
 490
 491         a->adapter = adapter_sigmoid;
 492         a->adapt_rate = -18;
 493         a->adapt_phase = 0.65;
 494         a->adapt_moves = 200;
 495         a->adapt_dir = -0.5;
 496
 497         a->zone_red = 0.45;
 498         a->zone_green = 0.50;
 499         a->score_step = 1;
 500         a->use_komi_ratchet = true;
 501         a->komi_ratchet_maxage = 0;
 502         a->komi_ratchet = 1000;
 503
 504         if (arg) {
 505                 char *optspec, *next = arg;
 506                 while (*next) {
 507                         optspec = next;
 508                         next += strcspn(next, ":");
 509                         if (*next) { *next++ = 0; } else { *next = 0; }
 510
 511                         char *optname = optspec;
 512                         char *optval = strchr(optspec, '=');
 513                         if (optval) *optval++ = 0;
 514
 515                         if (!strcasecmp(optname, "lead_moves") && optval) {
 516                                 /* Do not adjust komi adaptively for first
 517                                  * N moves. */
 518                                 a->lead_moves = atoi(optval);
 519                         } else if (!strcasecmp(optname, "max_losing_komi") && optval) {
 520                                 a->max_losing_komi = atof(optval);
 521                         } else if (!strcasecmp(optname, "losing_komi_stop") && optval) {
 522                                 a->losing_komi_stop = atof(optval);
 523                         } else if (!strcasecmp(optname, "indicator")) {
 524                                 /* Adaptatation indicator - how to decide
 525                                  * the adaptation rate and direction. */
 526                                 if (!strcasecmp(optval, "value")) {
 527                                         /* Winrate w/ komi so far. */
 528                                         a->indicator = komi_by_value;
 529                                 } else if (!strcasecmp(optval, "score")) {
 530                                         /* Expected score w/ current komi. */
 531                                         a->indicator = komi_by_score;
 532                                 } else {
 533                                         fprintf(stderr, "UCT: Invalid indicator %s\n", optval);
 534                                         exit(1);
 535                                 }
 536
 537                                 /* value indicator settings */
 538                         } else if (!strcasecmp(optname, "zone_red") && optval) {
 539                                 a->zone_red = atof(optval);
 540                         } else if (!strcasecmp(optname, "zone_green") && optval) {
 541                                 a->zone_green = atof(optval);
 542                         } else if (!strcasecmp(optname, "score_step") && optval) {
 543                                 a->score_step = atoi(optval);
 544                         } else if (!strcasecmp(optname, "score_step_byavg") && optval) {
 545                                 a->score_step_byavg = atof(optval);
 546                         } else if (!strcasecmp(optname, "use_komi_ratchet")) {
 547                                 a->use_komi_ratchet = !optval || atoi(optval);
 548                         } else if (!strcasecmp(optname, "losing_komi_ratchet")) {
 549                                 a->losing_komi_ratchet = !optval || atoi(optval);
 550                         } else if (!strcasecmp(optname, "komi_ratchet_age") && optval) {
 551                                 a->komi_ratchet_maxage = atoi(optval);
 552
 553                                 /* score indicator settings */
 554                         } else if (!strcasecmp(optname, "adapter") && optval) {
 555                                 /* Adaptatation method. */
 556                                 if (!strcasecmp(optval, "sigmoid")) {
 557                                         a->adapter = adapter_sigmoid;
 558                                 } else if (!strcasecmp(optval, "linear")) {
 559                                         a->adapter = adapter_linear;
 560                                 } else {
 561                                         fprintf(stderr, "UCT: Invalid adapter %s\n", optval);
 562                                         exit(1);
 563                                 }
 564                         } else if (!strcasecmp(optname, "adapt_base") && optval) {
 565                                 /* Adaptation base rate; see above. */
 566                                 a->adapt_base = atof(optval);
 567                         } else if (!strcasecmp(optname, "adapt_rate") && optval) {
 568                                 /* Adaptation slope; see above. */
 569                                 a->adapt_rate = atof(optval);
 570                         } else if (!strcasecmp(optname, "adapt_phase") && optval) {
 571                                 /* Adaptation phase shift; see above. */
 572                                 a->adapt_phase = atof(optval);
 573                         } else if (!strcasecmp(optname, "adapt_moves") && optval) {
 574                                 /* Adaptation move amount; see above. */
 575                                 a->adapt_moves = atoi(optval);
 576                         } else if (!strcasecmp(optname, "adapt_aport")) {
 577                                 a->adapt_aport = !optval || atoi(optval);
 578                         } else if (!strcasecmp(optname, "adapt_dir") && optval) {
 579                                 /* Adaptation direction vector; see above. */
 580                                 a->adapt_dir = atof(optval);
 581
 582                         } else {
 583                                 fprintf(stderr, "uct: Invalid dynkomi argument %s or missing value\n", optname);
 584                                 exit(1);
 585                         }
 586                 }
 587         }
 588
 589         return d;
 590 }