/**
* @param samples The number of input vectors the error is sampled over
* @return Mean-squared error of this origin over randomly selected points
*/
public float[] getError(int samples) {
float[] result = new float[getDimensions()];
if (myNode instanceof NEFEnsemble) {
NEFEnsemble ensemble = (NEFEnsemble) myNode;
VectorGenerator vg = new RandomHypersphereVG(false, 1, 0);
float[][] unscaled = vg.genVectors(samples, ensemble.getDimension());
float[][] input = new float[unscaled.length][];
for (int i = 0; i < input.length; i++) {
input[i] = MU.prodElementwise(unscaled[i], ensemble.getRadii());
}
float[][] idealOutput = NEFUtil.getOutput(this, input, SimulationMode.DIRECT);
float[][] actualOutput = NEFUtil.getOutput(this, input, SimulationMode.CONSTANT_RATE);
float[][] error = MU.transpose(MU.difference(actualOutput, idealOutput));
for (int i = 0; i < error.length; i++) {
result[i] = MU.prod(error[i], error[i]) / error[i].length;
}
} else {
ourLogger.warn(
"Can't calculate error of a DecodedOrigin unless it belongs to an NEFEnsemble");
}
return result;
}
public DecodedOrigin clone(Node node) throws CloneNotSupportedException {
if (!(node instanceof DecodableEnsemble)) {
throw new CloneNotSupportedException("Error cloning DecodedOrigin: Invalid node type");
}
try {
DecodableEnsemble de = (DecodableEnsemble) node;
DecodedOrigin result = (DecodedOrigin) super.clone();
result.setDecoders(MU.clone(myDecoders));
Function[] functions = new Function[myFunctions.length];
for (int i = 0; i < functions.length; i++) {
functions[i] = myFunctions[i].clone();
}
result.myFunctions = functions;
result.myNodeOrigin = myNodeOrigin;
result.myNodes = de.getNodes();
result.myNode = de;
result.myOutput = (RealOutput) myOutput.clone();
if (myNoise != null) {
result.setNoise(myNoise.clone());
}
result.setMode(myMode);
return result;
} catch (CloneNotSupportedException e) {
throw new CloneNotSupportedException("Error cloning DecodedOrigin: " + e.getMessage());
}
}
/** @param decoders New decoding vectors (row per Node) */
public void setDecoders(float[][] decoders) {
assert MU.isMatrix(decoders);
assert myDecoders.length == decoders.length;
assert myDecoders[0].length == decoders[0].length;
myDecoders = decoders;
}
/**
* With this constructor decoding vectors are specified by the caller.
*
* @param node The parent Node
* @param name As in other constructor
* @param nodes As in other constructor
* @param nodeOrigin Name of the Origin on each given node from which output is to be decoded
* @param functions As in other constructor
* @param decoders Decoding vectors which are scaled by the main output of each Node, and then
* summed, to estimate the same function of the ensembles state vector that is defined by the
* 'functions' arg. The 'functions' arg is still needed, because in DIRECT SimulationMode,
* these functions are used directly. The 'decoders' arg allows the caller to provide decoders
* that are generated with non-default methods or parameters (eg an unusual number of singular
* values). Must be a matrix with one row per Node and one column per function.
* @throws StructuralException If dimensions.length != neurons.length, decoders is not a matrix
* (ie all elements with same length), or if the number of columns in decoders is not equal to
* the number of functions
*/
public DecodedOrigin(
Node node,
String name,
Node[] nodes,
String nodeOrigin,
Function[] functions,
float[][] decoders)
throws StructuralException {
checkFunctionDimensions(functions);
if (!MU.isMatrix(decoders)) {
throw new StructuralException("Elements of decoders do not all have the same length");
}
if (decoders[0].length != functions.length) {
throw new StructuralException(
"Number of decoding functions and dimension of decoding vectors must be the same");
}
if (decoders.length != nodes.length) {
throw new StructuralException("Number of decoding vectors and Neurons must be the same");
}
myNode = node;
myName = name;
myNodes = nodes;
myNodeOrigin = nodeOrigin;
myFunctions = functions;
myDecoders = decoders;
myMode = SimulationMode.DEFAULT;
myIntegrator = new EulerIntegrator(.001f);
reset(false);
}
private float[] getDynamicDecoder(int i, float input, float startTime, float endTime) {
float[] result = myDecoders[i];
if (mySTPDynamicsTemplate
!= null) { // TODO: could use a NullDynamics here instead of null (to allow nulling in
// config tree)
// TODO: could recycle a mutable time series here to avoid object creation
TimeSeries inputSeries =
new TimeSeries1DImpl(
new float[] {startTime, endTime}, new float[] {input, input}, Units.UNK);
TimeSeries outputSeries = myIntegrator.integrate(mySTPDynamics[i], inputSeries);
float scaleFactor = outputSeries.getValues()[outputSeries.getValues().length - 1][0];
mySTPHistory[i] = scaleFactor;
result = MU.prod(result, scaleFactor);
}
return result;
}
/**
* With this constructor the target is a signal over time rather than a function.
*
* @param node The parent Node
* @param name As in other constructor
* @param nodes As in other constructor
* @param nodeOrigin Name of the Origin on each given node from which output is to be decoded
* @param targetSignal Signal over time that this origin should produce.
* @param approximator A LinearApproximator that can be used to approximate new signals as a
* weighted sum of the node outputs.
*/
public DecodedOrigin(
Node node,
String name,
Node[] nodes,
String nodeOrigin,
TimeSeries targetSignal,
LinearApproximator approximator)
throws StructuralException {
myNode = node;
myName = name;
myNodes = nodes;
myNodeOrigin = nodeOrigin;
myFunctions = new FixedSignalFunction[targetSignal.getDimension()];
for (int i = 0; i < targetSignal.getDimension(); i++) // these are only used in direct mode
myFunctions[i] = new FixedSignalFunction(targetSignal.getValues(), i);
myDecoders = findDecoders(nodes, MU.transpose(targetSignal.getValues()), approximator);
myMode = SimulationMode.DEFAULT;
myIntegrator = new EulerIntegrator(.001f);
reset(false);
}
