org.jscience.mathematics.analysis.estimation
Class WeightedMeasurement

java.lang.Object
  org.jscience.mathematics.analysis.estimation.WeightedMeasurement

Direct Known Subclasses:

AbstractCurveFitter.FitMeasurement

public abstract class WeightedMeasurement
extends java.lang.Object

This class represents measurements in estimation problems.

This abstract class implements all the methods needed to handle measurements in a general way. It defines neither the getTheoreticalValue nor the getPartial methods, which should be defined by sub-classes according to the specific problem.

The getTheoreticalValue and getPartial methods should always use the current estimate of the parameters set by the solver in the problem. These parameters can be retrieved through the EstimationProblem.getAllParameters method if the measurements are independant of the problem, or directly if they are implemented as inner classes of the problem.

The instances for which the ignored flag is set through the setIgnored method are ignored by the solvers. This can be used to reject wrong measurements at some steps of the estimation.

See Also:

EstimationProblem

Constructor Summary

WeightedMeasurement(double weight, double measuredValue)
Simple constructor.

WeightedMeasurement(double weight, double measuredValue, boolean ignored)
Simple constructor.

Method Summary

double	getMeasuredValue() Get the measured value
abstract double	getPartial(EstimatedParameter parameter) Get the partial derivative of the measurement according to the parameter.
double	getResidual() Get the residual for this measurement The residual is the measured value minus the theoretical value.
abstract double	getTheoreticalValue() Get the theoretical value expected for this measurement The theoretical value is the value expected for this measurement if the model and its parameter were all perfectly known.
double	getWeight() Get the weight of the measurement in the least squares problem
boolean	isIgnored() Check if this measurement should be ignored
void	setIgnored(boolean ignored) Set the ignore flag to the specified value Setting the ignore flag to true allow to reject wrong measurements, which sometimes can be detected only rather late.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WeightedMeasurement

public WeightedMeasurement(double weight,
                           double measuredValue)

Simple constructor. Build a measurement with the given parameters, and set its ignore flag to false.

Parameters:

weight - weight of the measurement in the least squares problem

measuredValue - measured value

WeightedMeasurement

public WeightedMeasurement(double weight,
                           double measuredValue,
                           boolean ignored)

Simple constructor. Build a measurement with the given parameters

Parameters:

weight - weight of the measurement in the least squares problem

measuredValue - measured value

ignored - true if the measurement should be ignored

Method Detail

getWeight

public double getWeight()

Get the weight of the measurement in the least squares problem

Returns:

weight

getMeasuredValue

public double getMeasuredValue()

Get the measured value

Returns:

measured value

getTheoreticalValue

public abstract double getTheoreticalValue()

Get the theoretical value expected for this measurement The theoretical value is the value expected for this measurement if the model and its parameter were all perfectly known.

Returns:

theoretical value

getResidual

public double getResidual()

Get the residual for this measurement The residual is the measured value minus the theoretical value.

Returns:

residual

getPartial

public abstract double getPartial(EstimatedParameter parameter)

Get the partial derivative of the measurement according to the parameter.

Parameters:

parameter - parameter against which the partial derivative should be computed

Returns:

partial derivative

setIgnored

public void setIgnored(boolean ignored)

Set the ignore flag to the specified value Setting the ignore flag to true allow to reject wrong measurements, which sometimes can be detected only rather late.

Parameters:

ignored - value for the ignore flag

isIgnored

public boolean isIgnored()

Check if this measurement should be ignored

Returns:

true if the measurement should be ignored