/// <summary>
/// Invoke this hook with a certain parameter registry if optional conditional criteria are satisfied.
/// </summary>
/// <param name="registry">The registry containing the required values for this hook's execution.</param>
/// <param name="resolver">A helper resolver for complex registry entries (automatically cached).</param>
public override void SubInvoke(IRegistry registry, IRegistryResolver resolver)
{
// we need copies of network and optimiser as to not affect the current internal state
INetwork network = (INetwork)resolver.ResolveGetSingle <INetwork>("network.self").DeepCopy();
BaseGradientOptimiser optimiser = (BaseGradientOptimiser)resolver.ResolveGetSingle <BaseGradientOptimiser>("optimiser.self").ShallowCopy();
INDArray desiredTargets = ParameterRegistry.Get <INDArray>("desired_targets");
IComputationHandler handler = new DebugHandler(Operator.Handler);
long[] inputShape = network.YieldExternalInputsLayerBuffers().First().Parameters.Get <long[]>("shape");
IDictionary <string, INDArray> block = DataUtils.MakeBlock("targets", desiredTargets); // desired targets don't change during execution
double desiredCost = ParameterRegistry.Get <double>("desired_cost"), currentCost = Double.MaxValue;
int maxOptimisationAttempts = ParameterRegistry.Get <int>("max_optimisation_attempts");
int maxOptimisationSteps = ParameterRegistry.Get <int>("max_optimisation_steps");
int optimisationSteps = 0;
INDArray maximisedInputs = CreateRandomisedInput(handler, inputShape);
for (int i = 0; i < maxOptimisationAttempts; i++)
{
optimisationSteps = 0;
do
{
// trace current inputs and run network as normal
uint traceTag = handler.BeginTrace();
block["inputs"] = handler.Trace(maximisedInputs.Reshape(ArrayUtils.Concatenate(new[] { 1L, 1L }, inputShape)), traceTag);
handler.BeginSession();
DataUtils.ProvideExternalInputData(network, block);
network.Run(handler, trainingPass: false);
// fetch current outputs and optimise against them (towards desired targets)
INDArray currentTargets = network.YieldExternalOutputsLayerBuffers().First(b => b.ExternalOutputs.Contains("external_default"))
.Outputs["external_default"].Get <INDArray>("activations");
INumber squaredDifference = handler.Sum(handler.Pow(handler.Subtract(handler.FlattenTimeAndFeatures(currentTargets), desiredTargets), 2));
handler.ComputeDerivativesTo(squaredDifference);
handler.EndSession();
INDArray gradient = handler.GetDerivative(block["inputs"]);
maximisedInputs = handler.ClearTrace(optimiser.Optimise("inputs", block["inputs"], gradient, handler));
currentCost = squaredDifference.GetValueAs <double>();
if (currentCost <= desiredCost)
{
goto Validation;
}
} while (++optimisationSteps < maxOptimisationSteps);
maximisedInputs = CreateRandomisedInput(handler, inputShape); // reset input
}
Validation:
maximisedInputs.ReshapeSelf(inputShape);
string sharedResultInput = ParameterRegistry.Get <string>("shared_result_input_key");
string sharedResultSuccess = ParameterRegistry.Get <string>("shared_result_success_key");
if (optimisationSteps >= maxOptimisationSteps)
{
_logger.Debug($"Aborted target maximisation for {desiredTargets}, failed after {maxOptimisationSteps} optimisation steps in {maxOptimisationAttempts} attempts (exceeded limit, current cost {currentCost} but desired {desiredCost}).");
resolver.ResolveSet(sharedResultSuccess, false, addIdentifierIfNotExists: true);
}
else
{
_logger.Debug($"Successfully finished target optimisation for {desiredTargets} after {optimiser} optimisation steps.");
resolver.ResolveSet(sharedResultSuccess, true, addIdentifierIfNotExists: true);
resolver.ResolveSet(sharedResultInput, maximisedInputs, addIdentifierIfNotExists: true);
}
}
public override string ToString()
{
return($"threshold criteria for \"{ParameterRegistry.Get<string>("parameter_identifier")}\" when {ParameterRegistry.Get<ComparisonTarget>("target")} {ParameterRegistry.Get<double>("threshold_value")}");
}
public override string ToString()
{
return($"extrema criteria for \"{ParameterRegistry.Get<string>("parameter_identifier")}\" when at {ParameterRegistry.Get<ExtremaTarget>("target")}");
}
public override string ToString()
{
return($"repeat criteria [{ParameterRegistry.Get<HookInvokeCriteria>("base_criteria")}] {ParameterRegistry.Get<long>("target_repetitions")} times");
}
public override bool CheckCriteria(IRegistry registry, IRegistryResolver resolver)
{
string parameter = ParameterRegistry.Get <string>("parameter_identifier");
object rawValue = SimpleDirectEntries[0] ? registry.Get(parameter) : resolver.ResolveGetSingle <object>(parameter);
double value = (double)Convert.ChangeType(rawValue, typeof(double));
bool thresholdReached = _InternalThresholdReached(value, ParameterRegistry.Get <double>("threshold_value"), ParameterRegistry.Get <ComparisonTarget>("target"));
bool fire = thresholdReached && (!ParameterRegistry.Get <bool>("last_check_met") || ParameterRegistry.Get <bool>("fire_continously"));
ParameterRegistry["last_check_met"] = thresholdReached;
return(fire);
}
public override MultiAndCriteria And(HookInvokeCriteria criteria)
{
ParameterRegistry.Get <IList <HookInvokeCriteria> >("criterias").Add(criteria);
return(this);
}
public override string ToString()
{
return($"multi and criteria [{string.Join(" and ", ParameterRegistry.Get<IList<HookInvokeCriteria>>("criterias"))}]");
}
/// <summary>Returns a string that represents the current object.</summary>
/// <returns>A string that represents the current object.</returns>
public override string ToString()
{
return("not criteria [" + ParameterRegistry.Get <HookInvokeCriteria>("criteria") + "]");
}
public override bool CheckCriteria(IRegistry registry, IRegistryResolver resolver)
{
return(!ParameterRegistry.Get <HookInvokeCriteria>("criteria").CheckCriteria(registry, resolver));
}
protected virtual void Report(int epoch, int iteration)
{
_logger.Info(string.Format(ParameterRegistry.Get <string>("format_string"), epoch, iteration));
}
/// <summary>
/// End a validation scoring session.
/// Write out results here.
/// </summary>
/// <param name="registry">The registry containing the required values for this hook's execution.</param>
/// <param name="resolver">A helper resolver for complex registry entries (automatically cached).</param>
protected override void ScoreEnd(IRegistry registry, IRegistryResolver resolver)
{
string resultKey = ParameterRegistry.Get <string>("result_key");
double accuracy = (double)ParameterRegistry.Get <int>("correct_classifications") / ParameterRegistry.Get <int>("total_classifications");
resolver.ResolveSet(resultKey, accuracy, true);
}
/// <summary>
/// Invoke this hook with a certain parameter registry.
/// </summary>
/// <param name="registry">The registry containing the required values for this hook's execution.</param>
/// <param name="resolver">A helper resolver for complex registry entries (automatically cached).</param>
public override void SubInvoke(IRegistry registry, IRegistryResolver resolver)
{
Action <IRegistry, IRegistryResolver> action = ParameterRegistry.Get <Action <IRegistry, IRegistryResolver> >("invoke_action");
action.Invoke(registry, resolver);
}