/// <summary>
/// Returns a graph of MDP States from the States matrices and Action label vector.
/// </summary>
/// <param name="states">State matrix.</param>
/// <param name="actions">Action label vector.</param>
/// <param name="statesP">Transition states matrix.</param>
/// <param name="reward">Reward value vector.</param>
/// <param name="properties">Feature properties from the original set.</param>
/// <param name="discretizer">Discretization function for generating unique state identifiers.</param>
/// <returns>IEnumerable<IMDPState></returns>
public static IEnumerable<MDPState> GetStates(Matrix states, Vector actions, Matrix statesP, Vector reward,
Math.Summary properties, IDiscretizer discretizer)
{
Math.Summary summary = (properties != null ? properties : Math.Summary.Summarize(states));
discretizer.Initialize(states, summary);
var sdist = new Dictionary<double, MDPState>();
var adist = new Dictionary<string, double>();
var results = new Dictionary<double, MDPState>();
for (int i = 0; i < states.Rows; i++)
{
double sid = discretizer.Discretize(states[i], summary);
if (!sdist.ContainsKey(sid))
{
sdist.Add(sid, MDPConverter.GetState(states[i], summary, discretizer));
results.Add(sid, sdist[sid]);
}
double tsid = discretizer.Discretize(statesP[i], summary);
MDPState tstate = (sdist.ContainsKey(tsid) ? sdist[tsid] : MDPConverter.GetState(statesP[i], summary, discretizer));
if (!sdist.ContainsKey(tsid))
sdist.Add(tsid, tstate);
string key = GetActionKey((int)sid, (int)tsid);
if (!adist.ContainsKey(key))
adist.Add(key, 1);
else
{
adist[key]++;
}
sdist[sid].Successors.Add(new MDPSuccessorState(MDPConverter.GetAction(actions[i], (int) sid, (int) tsid), 0, tstate, reward[i]));
if (results.ContainsKey(tsid))
results.Remove(tsid);
}
foreach (var state in sdist.Values)
{
double sum = state.Successors.Sum(s => adist[GetActionKey(state.Id, s.State.Id)]);
foreach (var successor in state.Successors)
{
var key = GetActionKey(state.Id, successor.State.Id);
((AI.Action) successor.Action).Probability = adist[key] / sum;
}
}
// return starting states
return results.Values;
}
/// <summary>
/// Converts the state vector into an MDP state.
/// </summary>
/// <param name="state">State vector.</param>
/// <param name="summary">Feature properties from the original set.</param>
/// <param name="discretizer">Discretization function for generating unique state identifiers.</param>
/// <returns>MDPState.</returns>
public static MDPState GetState(Vector state, Summary summary, IDiscretizer discretizer)
{
return(new MDPState((int)discretizer.Discretize(state, summary))
{
Features = state
});
}
/// <summary>
/// Converts the state vector into an MDP state.
/// </summary>
/// <param name="state">State vector.</param>
/// <param name="summary">Feature properties from the original set.</param>
/// <param name="discretizer">Discretization function for generating unique state identifiers.</param>
/// <returns>MDPState.</returns>
public static MDPState GetState(Vector state, Summary summary, IDiscretizer discretizer)
{
return new MDPState((int)discretizer.Discretize(state, summary)) { Features = state };
}
/// <summary>
/// Returns a graph of MDP States from the States matrices and Action label vector.
/// </summary>
/// <param name="states">State matrix.</param>
/// <param name="actions">Action label vector.</param>
/// <param name="statesP">Transition states matrix.</param>
/// <param name="reward">Reward value vector.</param>
/// <param name="properties">Feature properties from the original set.</param>
/// <param name="discretizer">Discretization function for generating unique state identifiers.</param>
/// <returns>IEnumerable<IMDPState></returns>
public static IEnumerable <MDPState> GetStates(
Matrix states,
Vector actions,
Matrix statesP,
Vector reward,
Summary properties,
IDiscretizer discretizer)
{
var summary = properties ?? Summary.Summarize(states);
discretizer.Initialize(states, summary);
var sdist = new Dictionary <double, MDPState>();
var adist = new Dictionary <string, double>();
var results = new Dictionary <double, MDPState>();
for (var i = 0; i < states.Rows; i++)
{
var sid = discretizer.Discretize(states[i], summary);
if (!sdist.ContainsKey(sid))
{
sdist.Add(sid, GetState(states[i], summary, discretizer));
results.Add(sid, sdist[sid]);
}
var tsid = discretizer.Discretize(statesP[i], summary);
var tstate = sdist.ContainsKey(tsid) ? sdist[tsid] : GetState(statesP[i], summary, discretizer);
if (!sdist.ContainsKey(tsid))
{
sdist.Add(tsid, tstate);
}
var key = GetActionKey((int)sid, (int)tsid);
if (!adist.ContainsKey(key))
{
adist.Add(key, 1);
}
else
{
adist[key]++;
}
sdist[sid].Successors.Add(
new MDPSuccessorState(GetAction(actions[i], (int)sid, (int)tsid), 0, tstate, reward[i]));
if (results.ContainsKey(tsid))
{
results.Remove(tsid);
}
}
foreach (var state in sdist.Values)
{
var sum = state.Successors.Sum(s => adist[GetActionKey(state.Id, s.State.Id)]);
foreach (var successor in state.Successors)
{
var key = GetActionKey(state.Id, successor.State.Id);
((Action)successor.Action).Probability = adist[key] / sum;
}
}
// return starting states
return(results.Values);
}
