Exemplo n.º 1
0
/**
 * @brief Returns the best known value for indicator_name matching the given key if the key is found, and
 * throws a coco_error otherwise.
 */
static double suite_biobj_get_best_value(const char *indicator_name, const char *key) {

  size_t i, count;
  double best_value = 0;
  char *curr_key;

  if (strcmp(indicator_name, "hyp") == 0) {

    curr_key = coco_allocate_string(COCO_PATH_MAX);
    count = sizeof(suite_biobj_best_values_hyp) / sizeof(char *);
    for (i = 0; i < count; i++) {
      sscanf(suite_biobj_best_values_hyp[i], "%s %lf", curr_key, &best_value);
      if (strcmp(curr_key, key) == 0) {
        coco_free_memory(curr_key);
        return best_value;
      }
    }

    coco_free_memory(curr_key);
    coco_warning("suite_biobj_get_best_value(): best value of %s could not be found; set to 1.0", key);
    return 1.0;

  } else {
    coco_error("suite_biobj_get_best_value(): indicator %s not supported", indicator_name);
    return 0; /* Never reached */
  }

  coco_error("suite_biobj_get_best_value(): unexpected exception");
  return 0; /* Never reached */
}
Exemplo n.º 2
0
/**
 * @brief Formatted string duplication, with va_list arguments.
 */
static char *coco_vstrdupf(const char *str, va_list args) {
  static char buf[COCO_VSTRDUPF_BUFLEN];
  long written;
  /* apparently args can only be used once, therefore
   * len = vsnprintf(NULL, 0, str, args) to find out the
   * length does not work. Therefore we use a buffer
   * which limits the max length. Longer strings should
   * never appear anyway, so this is rather a non-issue. */

#if 0
  written = vsnprintf(buf, COCO_VSTRDUPF_BUFLEN - 2, str, args);
  if (written < 0)
  coco_error("coco_vstrdupf(): vsnprintf failed on '%s'", str);
#else /* less safe alternative, if vsnprintf is not available */
  assert(strlen(str) < COCO_VSTRDUPF_BUFLEN / 2 - 2);
  if (strlen(str) >= COCO_VSTRDUPF_BUFLEN / 2 - 2)
    coco_error("coco_vstrdupf(): string is too long");
  written = vsprintf(buf, str, args);
  if (written < 0)
    coco_error("coco_vstrdupf(): vsprintf failed on '%s'", str);
#endif
  if (written > COCO_VSTRDUPF_BUFLEN - 3)
    coco_error("coco_vstrdupf(): A suspiciously long string is tried to being duplicated '%s'", buf);
  return coco_strdup(buf);
}
Exemplo n.º 3
0
void *coco_allocate_memory(const size_t size) {
  void *data;
  if (size == 0) {
    coco_error("coco_allocate_memory() called with 0 size.");
    return NULL; /* never reached */
  }
  data = malloc(size);
  if (data == NULL)
    coco_error("coco_allocate_memory() failed.");
  return data;
}
Exemplo n.º 4
0
/**
 * The archive always contains the two extreme solutions
 */
coco_archive_t *coco_archive(const char *suite_name,
                             const size_t function,
                             const size_t dimension,
                             const size_t instance) {

  coco_archive_t *archive = coco_archive_allocate();
  int output_precision = 15;
  coco_suite_t *suite;
  char *suite_instance = coco_strdupf("instances: %lu", (unsigned long) instance);
  char *suite_options = coco_strdupf("dimensions: %lu function_indices: %lu",
  		(unsigned long) dimension, (unsigned long) function);
  coco_problem_t *problem;
  char *text;
  int update;

  suite = coco_suite(suite_name, suite_instance, suite_options);
  if (suite == NULL) {
    coco_error("coco_archive(): cannot create suite '%s'", suite_name);
    return NULL; /* Never reached */
  }
  problem = coco_suite_get_next_problem(suite, NULL);
  if (problem == NULL) {
    coco_error("coco_archive(): cannot create problem f%02lu_i%02lu_d%02lu in suite '%s'",
    		(unsigned long) function, (unsigned long) instance, (unsigned long) dimension, suite_name);
    return NULL; /* Never reached */
  }

  /* Store the ideal and nadir points */
  archive->ideal = coco_duplicate_vector(problem->best_value, 2);
  archive->nadir = coco_duplicate_vector(problem->nadir_value, 2);

  /* Add the extreme points to the archive */
  text = coco_strdupf("0\t%.*e\t%.*e\n", output_precision, archive->nadir[0], output_precision, archive->ideal[1]);
  update = coco_archive_add_solution(archive, archive->nadir[0], archive->ideal[1], text);
  coco_free_memory(text);
  assert(update == 1);

  text = coco_strdupf("0\t%.*e\t%.*e\n", output_precision, archive->ideal[0], output_precision, archive->nadir[1]);
  update = coco_archive_add_solution(archive, archive->ideal[0], archive->nadir[1], text);
  coco_free_memory(text);
  assert(update == 1);

  archive->extreme1 = archive->tree->head;
  archive->extreme2 = archive->tree->tail;
  assert(archive->extreme1 != archive->extreme2);

  coco_free_memory(suite_instance);
  coco_free_memory(suite_options);
  coco_suite_free(suite);

  return archive;
}
Exemplo n.º 5
0
/**
 * @brief Creates and returns a string with removed characters between from and to.
 *
 * If you wish to remove characters from the beginning of the string, set from to "".
 * If you wish to remove characters until the end of the string, set to to "".
 *
 * The caller is responsible for freeing the allocated memory using coco_free_memory().
 */
static char *coco_remove_from_string(const char *string, const char *from, const char *to) {

  char *result, *start, *stop;

  result = coco_strdup(string);

  if (strcmp(from, "") == 0) {
    /* Remove from the start */
    start = result;
  } else
    start = strstr(result, from);

  if (strcmp(to, "") == 0) {
    /* Remove until the end */
    stop = result + strlen(result);
  } else
    stop = strstr(result, to);

  if ((start == NULL) || (stop == NULL) || (stop < start)) {
    coco_error("coco_remove_from_string(): failed to remove characters between %s and %s from string %s",
        from, to, string);
    return NULL; /* Never reached */
  }

  memmove(start, stop, strlen(stop) + 1);

  return result;
}
Exemplo n.º 6
0
/**
 * @brief Sets the instances associated with years for the bbob suite.
 */
static const char *suite_bbob_get_instances_by_year(const int year) {

  if (year == 2009) {
    return "1-5,1-5,1-5";
  }
  else if (year == 2010) {
    return "1-15";
  }
  else if (year == 2012) {
    return "1-5,21-30";
  }
  else if (year == 2013) {
    return "1-5,31-40";
  }
  else if (year == 2015) {
    return "1-5,41-50";
  }
  else if (year == 2016) {
    return "1-5,51-60";
  }
  else {
    coco_error("suite_bbob_get_instances_by_year(): year %d not defined for suite_bbob", year);
    return NULL;
  }
}
Exemplo n.º 7
0
/**
 * Evaluates and logs the given solution (as the coco_evaluate_function), but does not return the evaluated
 * value.
 *
 * @note None of the observers implements this function yet!
 * @note x must point to a correctly sized allocated memory region.

 * @param problem The given COCO problem.
 * @param x The decision vector.
 */
void coco_recommend_solution(coco_problem_t *problem, const double *x) {
  assert(problem != NULL);
  if (problem->recommend_solution == NULL) {
    coco_error("coco_recommend_solutions(): No recommend solution function implemented for problem %s",
        problem->problem_id);
  }
  problem->recommend_solution(problem, x);
}
Exemplo n.º 8
0
/**
 * @note None of the problems implement this function yet!
 * @note Both x and y must point to correctly sized allocated memory regions.
 *
 * @param problem The given COCO problem.
 * @param x The decision vector.
 * @param y The vector of constraints that is the result of the evaluation.
 */
void coco_evaluate_constraint(coco_problem_t *problem, const double *x, double *y) {
  /* implements a safer version of problem->evaluate(problem, x, y) */
  assert(problem != NULL);
  if (problem->evaluate_constraint == NULL) {
    coco_error("coco_evaluate_constraint(): No constraint function implemented for problem %s",
        problem->problem_id);
  }
  problem->evaluate_constraint(problem, x, y);
}
Exemplo n.º 9
0
static void lnd_evaluate_function(coco_problem_t *self, const double *x, double *y) {
  _log_nondominating_t *data;
  data = coco_get_transform_data(self);

  coco_evaluate_function(coco_get_transform_inner_problem(self), x, y);
  data->number_of_evaluations++;

  /* Open logfile if it is not alread open */
  if (data->logfile == NULL) {
    data->logfile = fopen(data->path, "w");
    if (data->logfile == NULL) {
      char *buf;
      const char *error_format =
          "lnd_evaluate_function() failed to open log file '%s'.";
      size_t buffer_size = snprintf(NULL, 0, error_format, data->path);
      buf = (char *)coco_allocate_memory(buffer_size);
      snprintf(buf, buffer_size, error_format, data->path);
      coco_error(buf);
      coco_free_memory(buf); /* Never reached */
    }
    fprintf(data->logfile, "# %zu variables  |  %zu objectives  |  func eval number\n",
            coco_get_number_of_variables(coco_get_transform_inner_problem(self)),
            coco_get_number_of_objectives(coco_get_transform_inner_problem(self)));
    
    /*********************************************************************/
    /* TODO: Temporary put it here, to check later */
    /* Allocate memory for the archive */
    mo_archive = (struct mococo_solutions_archive *) malloc(1 * sizeof(struct mococo_solutions_archive));
    mococo_allocate_archive(mo_archive, data->max_size_of_archive,
                          coco_get_number_of_variables(coco_get_transform_inner_problem(self)),
                          coco_get_number_of_objectives(coco_get_transform_inner_problem(self)), 1);
    /*********************************************************************/
  }
  
  /********************************************************************************/
  /* Finish evaluations of 1 single solution of the pop, with nObj objectives,
   * now update the archive with this newly evaluated solution and check its nondomination. */
  mococo_push_to_archive(&x, &y, mo_archive, 1, data->number_of_evaluations);
  mococo_pareto_filtering(mo_archive);  /***** TODO: IMPROVE THIS ROUTINE *****/
  mococo_mark_updates(mo_archive, data->number_of_evaluations);
  
  /* Write out a line for this newly evaluated solution if it is nondominated */
  // write main info to the log file for pfront
  for (size_t i=0; i < mo_archive->updatesize; i++) {
      entry = mo_archive->update[i];
      for (size_t j=0; j < coco_get_number_of_variables(coco_get_transform_inner_problem(self)); j++) // all decision variables of a solution
          fprintf(data->logfile, "%13.10e\t", entry->var[j]);
      for (size_t k=0; k < coco_get_number_of_objectives(coco_get_transform_inner_problem(self)); k++) // all objective values of a solution
          fprintf(data->logfile, "%13.10e\t", entry->obj[k]);
      fprintf(data->logfile, "%zu", entry->birth);  // its timestamp (FEval)
      fprintf(data->logfile, "\n");  // go to the next line for another solution
  }
  /********************************************************************************/
  
  /* Flush output so that impatient users can see progress. */
  fflush(data->logfile);
}
Exemplo n.º 10
0
/**
 * @brief Sets the instances associated with years for the bbob-biobj suite.
 */
static const char *suite_biobj_get_instances_by_year(const int year) {

  if (year == 2016) {
    return "1-10";
  }
  else {
    coco_error("suite_biobj_get_instances_by_year(): year %d not defined for suite_biobj", year);
    return NULL;
  }
}
Exemplo n.º 11
0
/**
 * Error when trying to create the file "path"
 */
static void logger_bbob2009_error_io(FILE *path, int errnum) {
  char *buf;
  const char *error_format = "Error opening file: %s\n ";
  /* "bbob2009_logger_prepare() failed to open log file '%s'.";*/
  size_t buffer_size = (size_t) snprintf(NULL, 0, error_format, path); /* to silence warning */
  buf = (char *) coco_allocate_memory(buffer_size);
  snprintf(buf, buffer_size, error_format, strerror(errnum), path);
  coco_error(buf);
  coco_free_memory(buf);
}
Exemplo n.º 12
0
/**
 * Formatted printing of a problem ID, mimicking
 * sprintf(coco_problem_get_id(problem), id, ...) while taking care
 * of memory (de-)allocations.
 *
 */
void coco_problem_set_id(coco_problem_t *problem, const char *id, ...) {
  va_list args;

  va_start(args, id);
  coco_free_memory(problem->problem_id);
  problem->problem_id = coco_vstrdupf(id, args);
  va_end(args);
  if (!coco_problem_id_is_fine(problem->problem_id)) {
    coco_error("Problem id should only contain standard chars, not like '%s'", coco_problem_get_id(problem));
  }
}
Exemplo n.º 13
0
/*
 * Shift all variables of ${inner_problem} by ${offset}.
 */
static coco_problem_t *f_transform_vars_shift(coco_problem_t *inner_problem,
                                              const double *offset,
                                              const int shift_bounds) {
  transform_vars_shift_data_t *data;
  coco_problem_t *self;
  if (shift_bounds)
    coco_error("shift_bounds not implemented.");

  data = coco_allocate_memory(sizeof(*data));
  data->offset = coco_duplicate_vector(offset, inner_problem->number_of_variables);
  data->shifted_x = coco_allocate_vector(inner_problem->number_of_variables);

  self = coco_transformed_allocate(inner_problem, data, transform_vars_shift_free);
  self->evaluate_function = transform_vars_shift_evaluate;
  return self;
}
Exemplo n.º 14
0
static coco_problem_t *logger_bbob2009(coco_problem_t *inner_problem, const char *alg_name) {
  logger_bbob2009_t *data;
  coco_problem_t *self;
  data = coco_allocate_memory(sizeof(*data));
  data->alg_name = coco_strdup(alg_name);
  if (bbob2009_logger_is_open)
    coco_error("The current bbob2009_logger (observer) must be closed before a new one is opened");
  /* This is the name of the folder which happens to be the algName */
  data->path = coco_strdup(alg_name);
  data->index_file = NULL;
  data->fdata_file = NULL;
  data->tdata_file = NULL;
  data->rdata_file = NULL;
  data->number_of_variables = inner_problem->number_of_variables;
  if (inner_problem->best_value == NULL) {
    /* coco_error("Optimal f value must be defined for each problem in order for the logger to work properly"); */
    /* Setting the value to 0 results in the assertion y>=optimal_fvalue being susceptible to failure */
    coco_warning("undefined optimal f value. Set to 0");
    data->optimal_fvalue = 0;
  } else {
    data->optimal_fvalue = *(inner_problem->best_value);
  }
  bbob2009_raisedOptValWarning = 0;

  data->idx_f_trigger = INT_MAX;
  data->idx_t_trigger = 0;
  data->idx_tdim_trigger = 0;
  data->f_trigger = DBL_MAX;
  data->t_trigger = 0;
  data->number_of_evaluations = 0;
  data->best_solution = coco_allocate_vector(inner_problem->number_of_variables);
  /* TODO: the following inits are just to be in the safe side and
   * should eventually be removed. Some fields of the bbob2009_logger struct
   * might be useless
   */
  data->function_id = coco_problem_get_suite_dep_function_id(inner_problem);
  data->instance_id = coco_problem_get_suite_dep_instance_id(inner_problem);
  data->written_last_eval = 1;
  data->last_fvalue = DBL_MAX;
  data->is_initialized = 0;

  self = coco_transformed_allocate(inner_problem, data, logger_bbob2009_free);
  self->evaluate_function = logger_bbob2009_evaluate;
  bbob2009_logger_is_open = 1;
  return self;
}
Exemplo n.º 15
0
/**
 * @brief Creates the transformation.
 */
static coco_problem_t *transform_vars_shift(coco_problem_t *inner_problem,
                                            const double *offset,
                                            const int shift_bounds) {
  transform_vars_shift_data_t *data;
  coco_problem_t *problem;
  size_t i;
  if (shift_bounds)
    coco_error("shift_bounds not implemented.");

  data = (transform_vars_shift_data_t *) coco_allocate_memory(sizeof(*data));
  data->offset = coco_duplicate_vector(offset, inner_problem->number_of_variables);
  data->shifted_x = coco_allocate_vector(inner_problem->number_of_variables);

  problem = coco_problem_transformed_allocate(inner_problem, data, transform_vars_shift_free, "transform_vars_shift");
  problem->evaluate_function = transform_vars_shift_evaluate;
  /* Compute best parameter */
  for (i = 0; i < problem->number_of_variables; i++) {
      problem->best_parameter[i] += data->offset[i];
  }
  return problem;
}
Exemplo n.º 16
0
/**
 * @brief Returns the first index where seq occurs in base and -1 if it doesn't.
 *
 * @note If there is an equivalent standard C function, this can/should be removed.
 */
static long coco_strfind(const char *base, const char *seq) {
  const size_t strlen_seq = strlen(seq);
  const size_t last_first_idx = strlen(base) - strlen(seq);
  size_t i, j;

  if (strlen(base) < strlen(seq))
    return -1;

  for (i = 0; i <= last_first_idx; ++i) {
    if (base[i] == seq[0]) {
      for (j = 0; j < strlen_seq; ++j) {
        if (base[i + j] != seq[j])
          break;
      }
      if (j == strlen_seq) {
        if (i > 1e9)
          coco_error("coco_strfind(): strange values observed i=%lu, j=%lu, strlen(base)=%lu",
          		(unsigned long) i, (unsigned long) j, (unsigned long) strlen(base));
        return (long) i;
      }
    }
  }
  return -1;
}
Exemplo n.º 17
0
/**
 * @brief Returns the problem from the toy suite that corresponds to the given parameters.
 *
 * @param suite The COCO suite.
 * @param function_idx Index of the function (starting from 0).
 * @param dimension_idx Index of the dimension (starting from 0).
 * @param instance_idx Index of the instance (starting from 0).
 * @return The problem that corresponds to the given parameters.
 */
static coco_problem_t *suite_toy_get_problem(coco_suite_t *suite,
                                             const size_t function_idx,
                                             const size_t dimension_idx,
                                             const size_t instance_idx) {


  coco_problem_t *problem = NULL;

  const size_t function = suite->functions[function_idx];
  const size_t dimension = suite->dimensions[dimension_idx];
  const size_t instance = suite->instances[instance_idx];

  if (function == 1) {
    problem = f_sphere_allocate(dimension);
  } else if (function == 2) {
    problem = f_ellipsoid_allocate(dimension);
  } else if (function == 3) {
    problem = f_rastrigin_allocate(dimension);
  } else if (function == 4) {
    problem = f_bueche_rastrigin_allocate(dimension);
  } else if (function == 5) {
    double xopt[40] = { 5.0 };
    problem = f_linear_slope_allocate(dimension, xopt);
  } else if (function == 6) {
    problem = f_rosenbrock_allocate(dimension);
  } else {
    coco_error("suite_toy_get_problem(): function %lu does not exist in this suite", function);
    return NULL; /* Never reached */
  }

  problem->suite_dep_function = function;
  problem->suite_dep_instance = instance;
  problem->suite_dep_index = coco_suite_encode_problem_index(suite, function_idx, dimension_idx, instance_idx);

  return problem;
}
Exemplo n.º 18
0
/**
 * @brief Initializes the indicator with name indicator_name.
 *
 * Opens files for writing and resets counters.
 */
static logger_biobj_indicator_t *logger_biobj_indicator(const logger_biobj_data_t *logger,
                                                        const coco_problem_t *problem,
                                                        const char *indicator_name) {

  coco_observer_t *observer;
  observer_biobj_data_t *observer_biobj;
  logger_biobj_indicator_t *indicator;
  char *prefix, *file_name, *path_name;
  int info_file_exists = 0;

  indicator = (logger_biobj_indicator_t *) coco_allocate_memory(sizeof(*indicator));
  observer = logger->observer;
  observer_biobj = (observer_biobj_data_t *) observer->data;

  indicator->name = coco_strdup(indicator_name);

  indicator->best_value = suite_biobj_get_best_value(indicator->name, problem->problem_id);
  indicator->next_target_id = 0;
  indicator->target_hit = 0;
  indicator->current_value = 0;
  indicator->additional_penalty = 0;
  indicator->overall_value = 0;

  /* Prepare the info file */
  path_name = coco_allocate_string(COCO_PATH_MAX);
  memcpy(path_name, observer->result_folder, strlen(observer->result_folder) + 1);
  coco_create_directory(path_name);
  file_name = coco_strdupf("%s_%s.info", problem->problem_type, indicator_name);
  coco_join_path(path_name, COCO_PATH_MAX, file_name, NULL);
  info_file_exists = coco_file_exists(path_name);
  indicator->info_file = fopen(path_name, "a");
  if (indicator->info_file == NULL) {
    coco_error("logger_biobj_indicator() failed to open file '%s'.", path_name);
    return NULL; /* Never reached */
  }
  coco_free_memory(file_name);
  coco_free_memory(path_name);

  /* Prepare the tdat file */
  path_name = coco_allocate_string(COCO_PATH_MAX);
  memcpy(path_name, observer->result_folder, strlen(observer->result_folder) + 1);
  coco_join_path(path_name, COCO_PATH_MAX, problem->problem_type, NULL);
  coco_create_directory(path_name);
  prefix = coco_remove_from_string(problem->problem_id, "_i", "_d");
  file_name = coco_strdupf("%s_%s.tdat", prefix, indicator_name);
  coco_join_path(path_name, COCO_PATH_MAX, file_name, NULL);
  indicator->tdat_file = fopen(path_name, "a");
  if (indicator->tdat_file == NULL) {
    coco_error("logger_biobj_indicator() failed to open file '%s'.", path_name);
    return NULL; /* Never reached */
  }
  coco_free_memory(file_name);
  coco_free_memory(path_name);

  /* Prepare the dat file */
  path_name = coco_allocate_string(COCO_PATH_MAX);
  memcpy(path_name, observer->result_folder, strlen(observer->result_folder) + 1);
  coco_join_path(path_name, COCO_PATH_MAX, problem->problem_type, NULL);
  coco_create_directory(path_name);
  file_name = coco_strdupf("%s_%s.dat", prefix, indicator_name);
  coco_join_path(path_name, COCO_PATH_MAX, file_name, NULL);
  indicator->dat_file = fopen(path_name, "a");
  if (indicator->dat_file == NULL) {
    coco_error("logger_biobj_indicator() failed to open file '%s'.", path_name);
    return NULL; /* Never reached */
  }

  /* Output header information to the info file */
  if (!info_file_exists) {
    /* Output algorithm name */
    fprintf(indicator->info_file, "algorithm = '%s', indicator = '%s', folder = '%s'\n%% %s", observer->algorithm_name,
        indicator_name, problem->problem_type, observer->algorithm_info);
  }
  if (observer_biobj->previous_function != problem->suite_dep_function) {
    fprintf(indicator->info_file, "\nfunction = %2lu, ", problem->suite_dep_function);
    fprintf(indicator->info_file, "dim = %2lu, ", problem->number_of_variables);
    fprintf(indicator->info_file, "%s", file_name);
  }

  coco_free_memory(prefix);
  coco_free_memory(file_name);
  coco_free_memory(path_name);

  /* Output header information to the dat file */
  fprintf(indicator->dat_file, "%%\n%% index = %ld, name = %s\n", problem->suite_dep_index, problem->problem_name);
  fprintf(indicator->dat_file, "%% instance = %ld, reference value = %.*e\n", problem->suite_dep_instance,
      logger->precision_f, indicator->best_value);
  fprintf(indicator->dat_file, "%% function evaluation | indicator value | target hit\n");

  /* Output header information to the tdat file */
  fprintf(indicator->tdat_file, "%%\n%% index = %ld, name = %s\n", problem->suite_dep_index, problem->problem_name);
  fprintf(indicator->tdat_file, "%% instance = %ld, reference value = %.*e\n", problem->suite_dep_instance,
      logger->precision_f, indicator->best_value);
  fprintf(indicator->tdat_file, "%% function evaluation | indicator value\n");

  return indicator;
}
Exemplo n.º 19
0
static coco_problem_t *f_gallagher_bbob_problem_allocate(const size_t function,
                                                         const size_t dimension,
                                                         const size_t instance,
                                                         const long rseed,
                                                         const size_t number_of_peaks,
                                                         const char *problem_id_template,
                                                         const char *problem_name_template) {

  f_gallagher_data_t *data;
  /* problem_name and best_parameter will be overwritten below */
  coco_problem_t *problem = coco_problem_allocate_from_scalars("Gallagher function",
      f_gallagher_evaluate, f_gallagher_free, dimension, -5.0, 5.0, 0.0);

  const size_t peaks_21 = 21;
  const size_t peaks_101 = 101;

  double fopt;
  size_t i, j, k, *rperm;
  double maxcondition = 1000.;
  /* maxcondition1 satisfies the old code and the doc but seems wrong in that it is, with very high
   * probability, not the largest condition level!!! */
  double maxcondition1 = 1000.;
  double *arrCondition;
  double fitvalues[2] = { 1.1, 9.1 };
  /* Parameters for generating local optima. In the old code, they are different in f21 and f22 */
  double b, c;

  data = coco_allocate_memory(sizeof(*data));
  /* Allocate temporary storage and space for the rotation matrices */
  data->number_of_peaks = number_of_peaks;
  data->xopt = coco_allocate_vector(dimension);
  data->rotation = bbob2009_allocate_matrix(dimension, dimension);
  data->x_local = bbob2009_allocate_matrix(dimension, number_of_peaks);
  data->arr_scales = bbob2009_allocate_matrix(number_of_peaks, dimension);

  if (number_of_peaks == peaks_101) {
    if (gallagher_peaks != NULL)
      coco_free_memory(gallagher_peaks);
    gallagher_peaks = coco_allocate_vector(peaks_101 * dimension);
    maxcondition1 = sqrt(maxcondition1);
    b = 10.;
    c = 5.;
  } else if (number_of_peaks == peaks_21) {
    if (gallagher_peaks != NULL)
      coco_free_memory(gallagher_peaks);
    gallagher_peaks = coco_allocate_vector(peaks_21 * dimension);
    b = 9.8;
    c = 4.9;
  } else {
    coco_error("f_gallagher(): '%lu' is a bad number of peaks", number_of_peaks);
  }
  data->rseed = rseed;
  bbob2009_compute_rotation(data->rotation, rseed, dimension);

  /* Initialize all the data of the inner problem */
  bbob2009_unif(gallagher_peaks, number_of_peaks - 1, data->rseed);
  rperm = (size_t *) coco_allocate_memory((number_of_peaks - 1) * sizeof(size_t));
  for (i = 0; i < number_of_peaks - 1; ++i)
    rperm[i] = i;
  qsort(rperm, number_of_peaks - 1, sizeof(size_t), f_gallagher_compare_doubles);

  /* Random permutation */
  arrCondition = coco_allocate_vector(number_of_peaks);
  arrCondition[0] = maxcondition1;
  data->peak_values = coco_allocate_vector(number_of_peaks);
  data->peak_values[0] = 10;
  for (i = 1; i < number_of_peaks; ++i) {
    arrCondition[i] = pow(maxcondition, (double) (rperm[i - 1]) / ((double) (number_of_peaks - 2)));
    data->peak_values[i] = (double) (i - 1) / (double) (number_of_peaks - 2) * (fitvalues[1] - fitvalues[0])
        + fitvalues[0];
  }
  coco_free_memory(rperm);

  rperm = (size_t *) coco_allocate_memory(dimension * sizeof(size_t));
  for (i = 0; i < number_of_peaks; ++i) {
    bbob2009_unif(gallagher_peaks, dimension, data->rseed + (long) (1000 * i));
    for (j = 0; j < dimension; ++j)
      rperm[j] = j;
    qsort(rperm, dimension, sizeof(size_t), f_gallagher_compare_doubles);
    for (j = 0; j < dimension; ++j) {
      data->arr_scales[i][j] = pow(arrCondition[i],
          ((double) rperm[j]) / ((double) (dimension - 1)) - 0.5);
    }
  }
  coco_free_memory(rperm);

  bbob2009_unif(gallagher_peaks, dimension * number_of_peaks, data->rseed);
  for (i = 0; i < dimension; ++i) {
    data->xopt[i] = 0.8 * (b * gallagher_peaks[i] - c);
    problem->best_parameter[i] = 0.8 * (b * gallagher_peaks[i] - c);
    for (j = 0; j < number_of_peaks; ++j) {
      data->x_local[i][j] = 0.;
      for (k = 0; k < dimension; ++k) {
        data->x_local[i][j] += data->rotation[i][k] * (b * gallagher_peaks[j * dimension + k] - c);
      }
      if (j == 0) {
        data->x_local[i][j] *= 0.8;
      }
    }
  }
  coco_free_memory(arrCondition);

  problem->data = data;

  /* Compute best solution */
  f_gallagher_evaluate(problem, problem->best_parameter, problem->best_value);

  fopt = bbob2009_compute_fopt(function, instance);
  problem = f_transform_obj_shift(problem, fopt);

  coco_problem_set_id(problem, problem_id_template, function, instance, dimension);
  coco_problem_set_name(problem, problem_name_template, function, instance, dimension);
  coco_problem_set_type(problem, "5-weakly-structured");

  return problem;
}
Exemplo n.º 20
0
/**
 * @brief Creates and returns a BBOB problem without needing the actual bbob suite.
 *
 * Useful for other suites as well (see for example suite_biobj.c).
 */
static coco_problem_t *coco_get_bbob_problem(const size_t function,
                                             const size_t dimension,
                                             const size_t instance) {
  coco_problem_t *problem = NULL;

  const char *problem_id_template = "bbob_f%03lu_i%02lu_d%02lu";
  const char *problem_name_template = "BBOB suite problem f%lu instance %lu in %luD";

  const long rseed = (long) (function + 10000 * instance);
  const long rseed_3 = (long) (3 + 10000 * instance);
  const long rseed_17 = (long) (17 + 10000 * instance);

  if (function == 1) {
    problem = f_sphere_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 2) {
    problem = f_ellipsoid_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 3) {
    problem = f_rastrigin_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 4) {
    problem = f_bueche_rastrigin_bbob_problem_allocate(function, dimension, instance, rseed_3,
        problem_id_template, problem_name_template);
  } else if (function == 5) {
    problem = f_linear_slope_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 6) {
    problem = f_attractive_sector_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 7) {
    problem = f_step_ellipsoid_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 8) {
    problem = f_rosenbrock_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 9) {
    problem = f_rosenbrock_rotated_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 10) {
    problem = f_ellipsoid_rotated_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 11) {
    problem = f_discus_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 12) {
    problem = f_bent_cigar_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 13) {
    problem = f_sharp_ridge_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 14) {
    problem = f_different_powers_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 15) {
    problem = f_rastrigin_rotated_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 16) {
    problem = f_weierstrass_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 17) {
    problem = f_schaffers_bbob_problem_allocate(function, dimension, instance, rseed, 10,
        problem_id_template, problem_name_template);
  } else if (function == 18) {
    problem = f_schaffers_bbob_problem_allocate(function, dimension, instance, rseed_17, 1000,
        problem_id_template, problem_name_template);
  } else if (function == 19) {
    problem = f_griewank_rosenbrock_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 20) {
    problem = f_schwefel_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 21) {
    problem = f_gallagher_bbob_problem_allocate(function, dimension, instance, rseed, 101,
        problem_id_template, problem_name_template);
  } else if (function == 22) {
    problem = f_gallagher_bbob_problem_allocate(function, dimension, instance, rseed, 21,
        problem_id_template, problem_name_template);
  } else if (function == 23) {
    problem = f_katsuura_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else if (function == 24) {
    problem = f_lunacek_bi_rastrigin_bbob_problem_allocate(function, dimension, instance, rseed,
        problem_id_template, problem_name_template);
  } else {
    coco_error("get_bbob_problem(): cannot retrieve problem f%lu instance %lu in %luD",
    		(unsigned long) function, (unsigned long) instance, (unsigned long) dimension);
    return NULL; /* Never reached */
  }

  return problem;
}
Exemplo n.º 21
0
/**
 * @brief Updates the archive and buffer trees with the given node.
 *
 * Checks for domination and updates the archive tree and the values of the indicators if the given node is
 * not weakly dominated by existing nodes in the archive tree. This is where the main computation of
 * indicator values takes place.
 *
 * @return 1 if the update was performed and 0 otherwise.
 */
static int logger_biobj_tree_update(logger_biobj_data_t *logger,
                                    const coco_problem_t *problem,
                                    logger_biobj_avl_item_t *node_item) {

  avl_node_t *node, *next_node, *new_node;
  int trigger_update = 0;
  int dominance;
  size_t i;
  int previous_unavailable = 0;

  /* Find the first point that is not worse than the new point (NULL if such point does not exist) */
  node = avl_item_search_right(logger->archive_tree, node_item, NULL);

  if (node == NULL) {
    /* The new point is an extremal point */
    trigger_update = 1;
    next_node = logger->archive_tree->head;
  } else {
    dominance = mo_get_dominance(node_item->y, ((logger_biobj_avl_item_t*) node->item)->y,
        logger->number_of_objectives);
    if (dominance > -1) {
      trigger_update = 1;
      next_node = node->next;
      if (dominance == 1) {
        /* The new point dominates the next point, remove the next point */
        if (logger->compute_indicators) {
          for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {
            logger->indicators[i]->current_value -= ((logger_biobj_avl_item_t*) node->item)->indicator_contribution[i];
          }
        }
        avl_item_delete(logger->buffer_tree, node->item);
        avl_node_delete(logger->archive_tree, node);
      }
    } else {
      /* The new point is dominated, nothing more to do */
      trigger_update = 0;
    }
  }

  if (!trigger_update) {
    logger_biobj_node_free(node_item, NULL);
  } else {
    /* Perform tree update */
    while (next_node != NULL) {
      /* Check the dominance relation between the new node and the next node. There are only two possibilities:
       * dominance = 0: the new node and the next node are nondominated
       * dominance = 1: the new node dominates the next node */
      node = next_node;
      dominance = mo_get_dominance(node_item->y, ((logger_biobj_avl_item_t*) node->item)->y,
          logger->number_of_objectives);
      if (dominance == 1) {
        /* The new point dominates the next point, remove the next point */
        if (logger->compute_indicators) {
          for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {
            logger->indicators[i]->current_value -= ((logger_biobj_avl_item_t*) node->item)->indicator_contribution[i];
          }
        }
        next_node = node->next;
        avl_item_delete(logger->buffer_tree, node->item);
        avl_node_delete(logger->archive_tree, node);
      } else {
        break;
      }
    }

    new_node = avl_item_insert(logger->archive_tree, node_item);
    avl_item_insert(logger->buffer_tree, node_item);

    if (logger->compute_indicators) {
      logger_biobj_check_if_within_ROI(problem, new_node);
      if (node_item->within_ROI) {
        /* Compute indicator value for new node and update the indicator value of the affected nodes */
        logger_biobj_avl_item_t *next_item, *previous_item;

        if (new_node->next != NULL) {
          next_item = (logger_biobj_avl_item_t*) new_node->next->item;
          if (next_item->within_ROI) {
            for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {
              logger->indicators[i]->current_value -= next_item->indicator_contribution[i];
              if (strcmp(logger->indicators[i]->name, "hyp") == 0) {
                next_item->indicator_contribution[i] = (node_item->y[0] - next_item->y[0])
                    / (problem->nadir_value[0] - problem->best_value[0])
                    * (problem->nadir_value[1] - next_item->y[1])
                    / (problem->nadir_value[1] - problem->best_value[1]);
              } else {
                coco_error(
                    "logger_biobj_tree_update(): Indicator computation not implemented yet for indicator %s",
                    logger->indicators[i]->name);
              }
              logger->indicators[i]->current_value += next_item->indicator_contribution[i];
            }
          }
        }

        previous_unavailable = 0;
        if (new_node->prev != NULL) {
          previous_item = (logger_biobj_avl_item_t*) new_node->prev->item;
          if (previous_item->within_ROI) {
            for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {
              if (strcmp(logger->indicators[i]->name, "hyp") == 0) {
                node_item->indicator_contribution[i] = (previous_item->y[0] - node_item->y[0])
                    / (problem->nadir_value[0] - problem->best_value[0])
                    * (problem->nadir_value[1] - node_item->y[1])
                    / (problem->nadir_value[1] - problem->best_value[1]);
              } else {
                coco_error(
                    "logger_biobj_tree_update(): Indicator computation not implemented yet for indicator %s",
                    logger->indicators[i]->name);
              }
            }
          } else {
            previous_unavailable = 1;
          }
        } else {
          previous_unavailable = 1;
        }

        if (previous_unavailable) {
          /* Previous item does not exist or is out of ROI, use reference point instead */
          for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {
            if (strcmp(logger->indicators[i]->name, "hyp") == 0) {
              node_item->indicator_contribution[i] = (problem->nadir_value[0] - node_item->y[0])
                  / (problem->nadir_value[0] - problem->best_value[0])
                  * (problem->nadir_value[1] - node_item->y[1])
                  / (problem->nadir_value[1] - problem->best_value[1]);
            } else {
              coco_error(
                  "logger_biobj_tree_update(): Indicator computation not implemented yet for indicator %s",
                  logger->indicators[i]->name);
            }
          }
        }

        for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {
          logger->indicators[i]->current_value += node_item->indicator_contribution[i];
        }
      }
    }
  }

  return trigger_update;
}
Exemplo n.º 22
0
/**
 * @brief Evaluates the function, increases the number of evaluations and outputs information based on the
 * observer options.
 */
static void logger_biobj_evaluate(coco_problem_t *problem, const double *x, double *y) {

  logger_biobj_data_t *logger;

  logger_biobj_avl_item_t *node_item;
  logger_biobj_indicator_t *indicator;
  avl_node_t *solution;
  int update_performed;
  size_t i;

  logger = (logger_biobj_data_t *) coco_problem_transformed_get_data(problem);

  /* Evaluate function */
  coco_evaluate_function(coco_problem_transformed_get_inner_problem(problem), x, y);
  logger->number_of_evaluations++;

  /* Update the archive with the new solution, if it is not dominated by or equal to existing solutions in
   * the archive */
  node_item = logger_biobj_node_create(x, y, logger->number_of_evaluations, logger->number_of_variables,
      logger->number_of_objectives);

  update_performed = logger_biobj_tree_update(logger, coco_problem_transformed_get_inner_problem(problem),
      node_item);

  /* If the archive was updated and you need to log all nondominated solutions, output the new solution to
   * nondom_file */
  if (update_performed && (logger->log_nondom_mode == LOG_NONDOM_ALL)) {
    logger_biobj_tree_output(logger->archive_file, logger->buffer_tree, logger->number_of_variables,
        logger->number_of_objectives, logger->log_vars, logger->precision_x, logger->precision_f);
    avl_tree_purge(logger->buffer_tree);

    /* Flush output so that impatient users can see progress. */
    fflush(logger->archive_file);
  }

  /* Perform output to the:
   * - dat file, if the archive was updated and a new target was reached for an indicator;
   * - tdat file, if the number of evaluations matches one of the predefined numbers.
   *
   * Note that a target is reached when the (best_value - current_value) <= relative_target_value
   * The relative_target_value is a target for indicator difference, not indicator value!
   */
  if (logger->compute_indicators) {
    for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++) {

      indicator = logger->indicators[i];
      indicator->target_hit = 0;

      /* If the update was performed, update the overall indicator value */
      if (update_performed) {
        /* Compute the overall_value of an indicator */
        if (strcmp(indicator->name, "hyp") == 0) {
          if (indicator->current_value == 0) {
            /* The additional penalty for hypervolume is the minimal distance from the nondominated set to the ROI */
            indicator->additional_penalty = DBL_MAX;
            if (logger->archive_tree->tail) {
              solution = logger->archive_tree->head;
              while (solution != NULL) {
                double distance = mo_get_distance_to_ROI(((logger_biobj_avl_item_t*) solution->item)->y,
                    problem->best_value, problem->nadir_value, problem->number_of_objectives);
                indicator->additional_penalty = coco_double_min(indicator->additional_penalty, distance);
                solution = solution->next;
              }
            }
            assert(indicator->additional_penalty >= 0);
          } else {
            indicator->additional_penalty = 0;
          }
          indicator->overall_value = indicator->best_value - indicator->current_value
              + indicator->additional_penalty;
        } else {
          coco_error("logger_biobj_evaluate(): Indicator computation not implemented yet for indicator %s",
              indicator->name);
        }

        /* Check whether a target was hit */
        while ((indicator->next_target_id < MO_NUMBER_OF_TARGETS)
            && (indicator->overall_value <= mo_relateive_target_values[indicator->next_target_id])) {
          /* A target was hit */
          indicator->target_hit = 1;
          if (indicator->next_target_id + 1 < MO_NUMBER_OF_TARGETS)
            indicator->next_target_id++;
          else
            break;
        }
      }

      /* Log to the dat file if a target was hit */
      if (indicator->target_hit) {
        fprintf(indicator->dat_file, "%lu\t%.*e\t%.*e\n", logger->number_of_evaluations, logger->precision_f,
            indicator->overall_value, logger->precision_f,
            mo_relateive_target_values[indicator->next_target_id - 1]);
      }

      /* Log to the tdat file if the number of evaluations matches one of the predefined numbers */
      if (coco_observer_evaluation_to_log(logger->number_of_evaluations, logger->number_of_variables)) {
        fprintf(indicator->tdat_file, "%lu\t%.*e\n", logger->number_of_evaluations, logger->precision_f,
            indicator->overall_value);
      }

    }
  }
}
Exemplo n.º 23
0
/**
 * @brief Initializes the biobjective logger.
 */
static coco_problem_t *logger_biobj(coco_observer_t *observer, coco_problem_t *inner_problem) {

  coco_problem_t *problem;
  logger_biobj_data_t *logger_biobj;
  observer_biobj_data_t *observer_biobj;
  const char nondom_folder_name[] = "archive";
  char *path_name, *file_name = NULL, *prefix;
  size_t i;

  if (inner_problem->number_of_objectives != 2) {
    coco_error("logger_biobj(): The bi-objective logger cannot log a problem with %d objective(s)", inner_problem->number_of_objectives);
    return NULL; /* Never reached. */
  }

  logger_biobj = (logger_biobj_data_t *) coco_allocate_memory(sizeof(*logger_biobj));

  logger_biobj->observer = observer;

  logger_biobj->number_of_evaluations = 0;
  logger_biobj->number_of_variables = inner_problem->number_of_variables;
  logger_biobj->number_of_objectives = inner_problem->number_of_objectives;
  logger_biobj->suite_dep_instance = inner_problem->suite_dep_instance;

  observer_biobj = (observer_biobj_data_t *) observer->data;
  /* Copy values from the observes that you might need even if they do not exist any more */
  logger_biobj->log_nondom_mode = observer_biobj->log_nondom_mode;
  logger_biobj->compute_indicators = observer_biobj->compute_indicators;
  logger_biobj->precision_x = observer->precision_x;
  logger_biobj->precision_f = observer->precision_f;

  if (((observer_biobj->log_vars_mode == LOG_VARS_LOW_DIM) && (inner_problem->number_of_variables > 5))
      || (observer_biobj->log_vars_mode == LOG_VARS_NEVER))
    logger_biobj->log_vars = 0;
  else
    logger_biobj->log_vars = 1;

  /* Initialize logging of nondominated solutions into the archive file */
  if (logger_biobj->log_nondom_mode != LOG_NONDOM_NONE) {

    /* Create the path to the file */
    path_name = coco_allocate_string(COCO_PATH_MAX);
    memcpy(path_name, observer->result_folder, strlen(observer->result_folder) + 1);
    coco_join_path(path_name, COCO_PATH_MAX, nondom_folder_name, NULL);
    coco_create_directory(path_name);

    /* Construct file name */
    prefix = coco_remove_from_string(inner_problem->problem_id, "_i", "_d");
    if (logger_biobj->log_nondom_mode == LOG_NONDOM_ALL)
      file_name = coco_strdupf("%s_nondom_all.adat", prefix);
    else if (logger_biobj->log_nondom_mode == LOG_NONDOM_FINAL)
      file_name = coco_strdupf("%s_nondom_final.adat", prefix);
    coco_join_path(path_name, COCO_PATH_MAX, file_name, NULL);
    if (logger_biobj->log_nondom_mode != LOG_NONDOM_NONE)
      coco_free_memory(file_name);
    coco_free_memory(prefix);

    /* Open and initialize the archive file */
    logger_biobj->archive_file = fopen(path_name, "a");
    if (logger_biobj->archive_file == NULL) {
      coco_error("logger_biobj() failed to open file '%s'.", path_name);
      return NULL; /* Never reached */
    }
    coco_free_memory(path_name);

    /* Output header information */
    fprintf(logger_biobj->archive_file, "%% instance = %ld, name = %s\n", inner_problem->suite_dep_instance, inner_problem->problem_name);
    if (logger_biobj->log_vars) {
      fprintf(logger_biobj->archive_file, "%% function evaluation | %lu objectives | %lu variables\n",
          inner_problem->number_of_objectives, inner_problem->number_of_variables);
    } else {
      fprintf(logger_biobj->archive_file, "%% function evaluation | %lu objectives \n",
          inner_problem->number_of_objectives);
    }
  }

  /* Initialize the AVL trees */
  logger_biobj->archive_tree = avl_tree_construct((avl_compare_t) avl_tree_compare_by_last_objective,
      (avl_free_t) logger_biobj_node_free);
  logger_biobj->buffer_tree = avl_tree_construct((avl_compare_t) avl_tree_compare_by_time_stamp, NULL);

  problem = coco_problem_transformed_allocate(inner_problem, logger_biobj, logger_biobj_free);
  problem->evaluate_function = logger_biobj_evaluate;

  /* Initialize the indicators */
  if (logger_biobj->compute_indicators) {
    for (i = 0; i < OBSERVER_BIOBJ_NUMBER_OF_INDICATORS; i++)
      logger_biobj->indicators[i] = logger_biobj_indicator(logger_biobj, inner_problem, observer_biobj_indicators[i]);

    observer_biobj->previous_function = (long) inner_problem->suite_dep_function;
  }

  return problem;
}
Exemplo n.º 24
0
/**
 * @brief Computes the instance number of the second problem/objective so that the resulting bi-objective
 * problem has more than a single optimal solution.
 *
 * Starts by setting instance2 = instance1 + 1 and increases this number until an appropriate instance has
 * been found (or until a maximum number of tries has been reached, in which case it throws a coco_error).
 * An appropriate instance is the one for which the resulting bi-objective problem (in any considered
 * dimension) has the ideal and nadir points apart enough in the objective space and the extreme optimal
 * points apart enough in the decision space. When the instance has been found, it is output through
 * coco_warning, so that the user can see it and eventually manually add it to suite_biobj_instances.
 */
static size_t suite_biobj_get_new_instance(coco_suite_t *suite,
                                           const size_t instance,
                                           const size_t instance1,
                                           const size_t num_bbob_functions,
                                           const size_t *bbob_functions) {
  size_t instance2 = 0;
  size_t num_tries = 0;
  const size_t max_tries = 1000;
  const double apart_enough = 1e-4;
  int appropriate_instance_found = 0, break_search, warning_produced = 0;
  coco_problem_t *problem1, *problem2, *problem = NULL;
  size_t d, f1, f2, i;
  size_t function1, function2, dimension;
  double norm;

  suite_biobj_t *data;
  assert(suite->data);
  data = (suite_biobj_t *) suite->data;

  while ((!appropriate_instance_found) && (num_tries < max_tries)) {
    num_tries++;
    instance2 = instance1 + num_tries;
    break_search = 0;

    /* An instance is "appropriate" if the ideal and nadir points in the objective space and the two
     * extreme optimal points in the decisions space are apart enough for all problems (all dimensions
     * and function combinations); therefore iterate over all dimensions and function combinations  */
    for (f1 = 0; (f1 < num_bbob_functions) && !break_search; f1++) {
      function1 = bbob_functions[f1];
      for (f2 = f1; (f2 < num_bbob_functions) && !break_search; f2++) {
        function2 = bbob_functions[f2];
        for (d = 0; (d < suite->number_of_dimensions) && !break_search; d++) {
          dimension = suite->dimensions[d];

          if (dimension == 0) {
            if (!warning_produced)
              coco_warning("suite_biobj_get_new_instance(): remove filtering of dimensions to get generally acceptable instances!");
            warning_produced = 1;
            continue;
          }

          problem1 = coco_get_bbob_problem(function1, dimension, instance1);
          problem2 = coco_get_bbob_problem(function2, dimension, instance2);
          if (problem) {
            coco_problem_stacked_free(problem);
            problem = NULL;
          }
          problem = coco_problem_stacked_allocate(problem1, problem2);

          /* Check whether the ideal and nadir points are too close in the objective space */
          norm = mo_get_norm(problem->best_value, problem->nadir_value, 2);
          if (norm < 1e-1) { /* TODO How to set this value in a sensible manner? */
            coco_debug(
                "suite_biobj_get_new_instance(): The ideal and nadir points of %s are too close in the objective space",
                problem->problem_id);
            coco_debug("norm = %e, ideal = %e\t%e, nadir = %e\t%e", norm, problem->best_value[0],
                problem->best_value[1], problem->nadir_value[0], problem->nadir_value[1]);
            break_search = 1;
          }

          /* Check whether the extreme optimal points are too close in the decision space */
          norm = mo_get_norm(problem1->best_parameter, problem2->best_parameter, problem->number_of_variables);
          if (norm < apart_enough) {
            coco_debug(
                "suite_biobj_get_new_instance(): The extremal optimal points of %s are too close in the decision space",
                problem->problem_id);
            coco_debug("norm = %e", norm);
            break_search = 1;
          }
        }
      }
    }
    /* Clean up */
    if (problem) {
      coco_problem_stacked_free(problem);
      problem = NULL;
    }

    if (break_search) {
      /* The search was broken, continue with next instance2 */
      continue;
    } else {
      /* An appropriate instance was found */
      appropriate_instance_found = 1;
      coco_info("suite_biobj_set_new_instance(): Instance %lu created from instances %lu and %lu", instance,
          instance1, instance2);

      /* Save the instance to new_instances */
      for (i = 0; i < data->max_new_instances; i++) {
        if (data->new_instances[i][0] == 0) {
          data->new_instances[i][0] = instance;
          data->new_instances[i][1] = instance1;
          data->new_instances[i][2] = instance2;
          break;
        };
      }
    }
  }

  if (!appropriate_instance_found) {
    coco_error("suite_biobj_get_new_instance(): Could not find suitable instance %lu in $lu tries", instance, num_tries);
    return 0; /* Never reached */
  }

  return instance2;
}