javaslam.filter
Class LinearGaussianFunction

java.lang.Object
  |
  +--javaslam.filter.LinearGaussianFunction

All Implemented Interfaces:

ExtendedVectorFunction, NoisyVectorFunction, VectorFunction

public class LinearGaussianFunction

extends Object

implements NoisyVectorFunction, ExtendedVectorFunction

A vector-valued function that takes a vector input, the bottom part of which is a white noise vector. In particular, if dim is the result of calling Gaussian.getDimension() on the Gaussian getNoiseModel(), then elements VectorFunction.getInputDim() - dim through VectorFunction.getInputDim() - 1 of the input vector are the noise variables.

Field Summary

protected Matrix	A The linear coefficient.
protected Gaussian	q The noise model.

Constructor Summary

LinearGaussianFunction(Matrix A, Gaussian q)
Constructor.

Method Summary

double[]	evaluate(double[] input) Evaluates this function at the supplied input.
int	getInputDim() Returns the input dimension of this function.
Gaussian	getNoiseModel() Returns the Gaussian distribution over the noise input.
int	getOutputDim() Returns the output dimension of this function.
double[][]	jacobian(double[] input) Evaluates the Jacobian of this function at the supplied input.

Methods inherited from class java.lang.Object

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

Field Detail

A

protected Matrix A

The linear coefficient.

q

protected Gaussian q

The noise model.

Constructor Detail

LinearGaussianFunction

public LinearGaussianFunction(Matrix A,
                              Gaussian q)

Constructor.

Parameters:

A - the linear coefficient

q - a Gaussian noise model (in moment form) that has as many dimensions as A has columns

Method Detail

getInputDim

public int getInputDim()

Returns the input dimension of this function.

Specified by:

getInputDim in interface VectorFunction

getOutputDim

public int getOutputDim()

Returns the output dimension of this function.

Specified by:

getOutputDim in interface VectorFunction

evaluate

public double[] evaluate(double[] input)

Evaluates this function at the supplied input.

Specified by:

evaluate in interface VectorFunction

Parameters:

input - an array with getInputDim() elements

Returns:

an array with getOutputDim() elements

getNoiseModel

public Gaussian getNoiseModel()

Returns the Gaussian distribution over the noise input.

Specified by:

getNoiseModel in interface NoisyVectorFunction

Returns:

the Gaussian distribution over the noise input

jacobian

public double[][] jacobian(double[] input)

Evaluates the Jacobian of this function at the supplied input.

Specified by:

jacobian in interface ExtendedVectorFunction

Parameters:

input - a vector with getInputDim() elements

Returns:

a matrix with getOutputDim() rows and getInputDim() columns; if y = f(x) then element (i, j) is the partial derivative of y_i with respect to x_j at input