Institut de Robòtica i Informàtica Industrial

GetMarginalCovariance

PURPOSE ^

Marginal covariance between the current pose and a previous one.

SYNOPSIS ^

function S=GetMarginalCovariance(F,step)

DESCRIPTION ^

 Marginal covariance between the current pose and a previous one.

 Returns the joint marginal covariance between the current robot's pose
 and the pose at time 'step'.

 The output matrix is organized such that the top left sub-matrix
 corresponds to the marginal covariance of the current robot's pose 
 and the bottom right one to marginal covariance of the at time 'step'.

 Note that each filter has a different way of computing the marginal
 covariances and the cross-covariances between poses. This is hidden in
 this function since it uses the GetPoseEstimation and 
 GetCrossCovarianceWithPose methods that can have particular 
 implementations for each filter.

 See also GetPoseEstimation, GetCrossCovarianceWithPose.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function S=GetMarginalCovariance(F,step)
0002 % Marginal covariance between the current pose and a previous one.
0003 %
0004 % Returns the joint marginal covariance between the current robot's pose
0005 % and the pose at time 'step'.
0006 %
0007 % The output matrix is organized such that the top left sub-matrix
0008 % corresponds to the marginal covariance of the current robot's pose
0009 % and the bottom right one to marginal covariance of the at time 'step'.
0010 %
0011 % Note that each filter has a different way of computing the marginal
0012 % covariances and the cross-covariances between poses. This is hidden in
0013 % this function since it uses the GetPoseEstimation and
0014 % GetCrossCovarianceWithPose methods that can have particular
0015 % implementations for each filter.
0016 %
0017 % See also GetPoseEstimation, GetCrossCovarianceWithPose.
0018 
0019   Pi=GetPoseEstimation(F,step);
0020   Pn=GetPoseEstimation(F,F.nSteps);
0021   
0022   n=1:F.dim;
0023   i=F.dim+1:2*F.dim;
0024   
0025   S=zeros(2*F.dim,2*F.dim);
0026   
0027   S(i,i)=get(Pi,'covariance');
0028   S(n,n)=get(Pn,'covariance');
0029   S(i,n)=GetCrossCovarianceWithPose(F,step);
0030   S(n,i)=S(i,n)';
0031


Institut de Robòtica i Informàtica Industrial

Generated on Fri 24-Jul-2009 12:32:50 by m2html © 2003