void Collective::calcNextState(double t, const VectorAccess<double>*x,
VectorAccess<double>*nx)
{ SiteOutputController *oc = site->outputcontroller;
oc->log( "at time %g, seeking consensus on proposal %s\n",
t, currentProposal.hexString() );
string strat = lparameters.facilitationStrategy();
//oc->log("facilitation strategy is '%s'\n", strat.c_str());
for (int i = 0; i < nX; ++i)
oc->log( "Individual %d values %s at %g\n", i, currentProposal.hexString(),
individuals[i].evaluate(currentProposal) );
if (strat == "each proposes one")
{ vector<BitString> amendments(nX);
vector< set<unsigned> > blocks(nX);
copyTo(x, nx);
for (int i = 0; i < nX; ++i)
{ // ask each individual to make proposed improvements
amendments[i] = individuals[i].makeProposal(currentProposal);
if (amendments[i] != currentProposal)
{ oc->log( "Individual %d proposes %s\n", i, amendments[i].hexString() );
oc->log( "Individual %d values %s at %g\n", i, amendments[i].hexString(),
individuals[i].evaluate(amendments[i]) );
// is the new proposal acceptable to everyone (or to anyone)?
for (int j = 0; j < nX; ++j)
if (j != i)
{ oc->log( "Individual %d values %s at %g\n", j, amendments[i].hexString(),
individuals[j].evaluate(amendments[i]) );
if ( ! individuals[j].acceptableReplacement(amendments[i], currentProposal) )
{ oc->log( "Individual %d blocks %s\n", j, amendments[i].hexString() );
blocks[i].insert(j);
}
}
}
else
oc->log( "Individual %d has no proposal\n", i );
}
// any proposals get no blocks?
finished = true;
for (int i = 0; i < nX; ++i)
if (blocks[i].size() == 0 && amendments[i] != currentProposal)
{ oc->log( "Proposal %s has no objections\n", amendments[i].hexString() );
// FIXME: we can't just take the first one each time
currentProposal = amendments[i];
finished = false;
break;
}
}
else if (strat == "one proposal at a time" or strat == "anyone proposes"
or strat == "blockers propose")
{ unsigned ind;
if (strat == "blockers propose")
{ vector<unsigned> blockers;
for (unsigned call_on = 0; call_on < individuals.size(); ++call_on)
if ( ! individuals[call_on].acceptable(currentProposal) )
{ oc->log("Individual %d blocks the proposal.\n", call_on);
blockers.push_back(call_on);
}
if (blockers.empty())
{ oc->log("Nobody blocks the proposal.\n");
finished = true;
return;
}
ind = blockers[rand_index(blockers.size())];
}
else
ind = rand_index(individuals.size());
finished = false;
BitString newProposal = individuals[ind].makeProposal(currentProposal);
int mnpf = lparameters.maxNumberOfProposalFailures();
if (mnpf == -1)
mnpf = 2*currentProposal.nBits();
if (newProposal == currentProposal)
{ oc->log("Individual %d has no proposal\n", ind);
++n_failures;
if (n_failures > mnpf)
{ finished = true;
}
}
else
{ oc->log("Individual %d proposes %s\n", ind, newProposal.hexString());
oc->log("Individual %d values %s at %g\n", ind, newProposal.hexString(),
individuals[ind].evaluate(newProposal));
bool accept = true;
for (unsigned judge = 0; judge < individuals.size(); ++judge)
if (judge != ind)
{ oc->log("Individual %d values %s at %g\n", judge,
newProposal.hexString(), individuals[judge].evaluate(newProposal));
if ( ! individuals[judge].acceptableReplacement(newProposal, currentProposal) )
{ oc->log("Individual %d blocks %s\n", judge, newProposal.hexString());
accept = false;
break;
}
}
if (accept)
{ oc->log("Proposal %s is accepted\n", newProposal.hexString());
currentProposal = newProposal;
}
else
{ oc->log("Proposal %s is rejected\n", newProposal.hexString());
++n_failures;
if (n_failures > mnpf)
{ finished = true;
}
}
}
}
else if (strat == "search minimum landscape")
{ //unsigned triesRemaining = lparameters.maxNumberOfProposalFailures();
typedef individuals_landscape_iterator<
typeof individuals.begin(), typeof individuals[0].fitnesslandscape>
LandscapeIteratorT;
LandscapeIteratorT li(individuals.begin(), individuals.end()),
le(individuals.end(), individuals.end());
MinimumLandscape<LandscapeIteratorT> ml(li, le);
oc->log("Search minimum landscape for improvement to %s\n",
currentProposal.hexString());
BitString nextProposal = ml.bestNeighbor(currentProposal);
oc->log("Next proposal is %s\n", nextProposal.hexString());
if (nextProposal == currentProposal)
finished = true;
else
currentProposal = nextProposal;
}
else
{ oc->log("Unknown strategy '%s'!\n", strat.c_str());
finished = true;
}
}
