/**
* @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;
}
/**
* 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);
}