Method Inst_JoinGroup

avida-core/source/cpu/cHardwareExperimental.cc:5203–5252

An organism joins a group by setting it opinion to the group id.

//! An organism joins a group by setting it opinion to the group id. 
bool cHardwareExperimental::Inst_JoinGroup(cAvidaContext& ctx)
{
  int opinion = m_world->GetConfig().DEFAULT_GROUP.Get();
  // Check if the org is currently part of a group
  assert(m_organism != 0);
	
  int prop_group_id = GetRegister(FindModifiedRegister(rBX));
  
  // check if this is a valid group
  if (m_world->GetConfig().USE_FORM_GROUPS.Get() == 2 &&
      !(m_world->GetEnvironment().IsGroupID(prop_group_id))) {
    return false; 
  }
  // injected orgs might not have an opinion
  if (m_organism->GetOrgInterface().HasOpinion(m_organism)) {
    opinion = m_organism->GetOpinion().first;
    
    //return false if org setting opinion to current one (avoid paying costs for not switching)
    if (opinion == prop_group_id) return false;
    
    // A random chance for failure to join group based on config, if failed return true for resource cost.
    if (m_world->GetConfig().JOIN_GROUP_FAILURE.Get() > 0) {
      int percent_failure = m_world->GetConfig().JOIN_GROUP_FAILURE.Get();
      double prob_failure = (double) percent_failure / 100.0;
      double rand = ctx.GetRandom().GetDouble();
      if (rand <= prob_failure) return true;
    }
    
    // If tolerances are on the org must pass immigration chance 
    if (m_world->GetConfig().TOLERANCE_WINDOW.Get() > 0) {
      m_organism->GetOrgInterface().AttemptImmigrateGroup(ctx,prop_group_id, m_organism);
      return true;
    }
    else {
      // otherwise, subtract org from current group
      m_organism->LeaveGroup(opinion);
    }
  }
  
  // Set the opinion
  m_organism->GetOrgInterface().SetOpinion(prop_group_id, m_organism);
  
  // Add org to group count
  if (m_organism->GetOrgInterface().HasOpinion(m_organism)) {
    opinion = m_organism->GetOpinion().first;	
    m_organism->JoinGroup(opinion);
  }
  
  return true;
}

// A predator can establish a new group, attempt to immigrate into the group that marked the cell in front of them, or become a nomad. 
bool cHardwareExperimental::Inst_ChangePredGroup(cAvidaContext& ctx)