Added LocalizationExample

matlab/examples/LocalizationExample.m

@@ -0,0 +1,58 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% GTSAM Copyright 2010, Georgia Tech Research Corporation, 
+% Atlanta, Georgia 30332-0415
+% All Rights Reserved
+% Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+% 
+% See LICENSE for the license information
+%
+% @brief Example of a simple 2D localization example
+% @author Frank Dellaert
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Assumptions
+%  - Robot poses are facing along the X axis (horizontal, to the right in 2D)
+%  - The robot moves 2 meters each step
+%  - The robot is on a grid, moving 2 meters each step
+
+%% Create the graph (defined in pose2SLAM.h, derived from NonlinearFactorGraph)
+graph = pose2SLAMGraph;
+
+%% Add two odometry factors
+odometry = gtsamPose2(2.0, 0.0, 0.0); % create a measurement for both factors (the same in this case)
+odometryNoise = gtsamSharedNoiseModel_Sigmas([0.2; 0.2; 0.1]); % 20cm std on x,y, 0.1 rad on theta
+graph.addOdometry(1, 2, odometry, odometryNoise);
+graph.addOdometry(2, 3, odometry, odometryNoise);
+
+%% Add three "GPS" measurements
+% We use Pose2 Priors here with high variance on theta
+noiseModel = gtsamSharedNoiseModel_Sigmas([0.1; 0.1; 10]);
+graph.addPrior(1, gtsamPose2(0.0, 0.0, 0.0), noiseModel);
+graph.addPrior(2, gtsamPose2(2.0, 0.0, 0.0), noiseModel);
+graph.addPrior(3, gtsamPose2(4.0, 0.0, 0.0), noiseModel);
+
+%% print
+graph.print(sprintf('\nFactor graph:\n'));
+
+%% Initialize to noisy points
+initialEstimate = pose2SLAMValues;
+initialEstimate.insertPose(1, gtsamPose2(0.5, 0.0, 0.2));
+initialEstimate.insertPose(2, gtsamPose2(2.3, 0.1,-0.2));
+initialEstimate.insertPose(3, gtsamPose2(4.1, 0.1, 0.1));
+initialEstimate.print(sprintf('\nInitial estimate:\n  '));
+
+%% Optimize using Levenberg-Marquardt optimization with an ordering from colamd
+result = graph.optimize(initialEstimate);
+result.print(sprintf('\nFinal result:\n  '));
+
+%% Plot Covariance Ellipses
+cla;
+plot(result.xs(),result.ys(),'k*-'); hold on
+marginals = graph.marginals(result);
+for i=1:result.size()
+    pose_i = result.pose(i);
+    P{i}=marginals.marginalCovariance(i);
+    plotPose2(pose_i,'g',P{i})
+end
+axis([-0.6 4.8 -1 1])
+axis equal

matlab/examples/OdometryExample.m

@@ -52,4 +52,5 @@ for i=1:result.size()
     P{i}=marginals.marginalCovariance(i);
     plotPose2(pose_i,'g',P{i})
 end
+axis([-0.6 4.8 -1 1])
 axis equal

matlab/examples/gtsamExamples.m

@@ -57,11 +57,6 @@ handles.output = hObject;
 % Update handles structure
 guidata(hObject, handles);
 
-% This sets up the initial plot - only do when we are invisible
-% so window can get raised using gtsamExamples.
-if strcmp(get(hObject,'Visible'),'off')
-    plot(rand(5));
-end
 
 % --- Outputs from this function are returned to the command line.
 function varargout = gtsamExamples_OutputFcn(hObject, eventdata, handles)
@@ -96,7 +91,10 @@ echo off
 
 % --- Executes on button press in Localization.
 function Localization_Callback(hObject, eventdata, handles)
-fprintf(1,'LocalizationExample not implemented yet\n');
+axes(handles.axes3);
+echo on
+LocalizationExample;
+echo off
 
 % --- Executes on button press in Pose2SLAM.
 function Pose2SLAM_Callback(hObject, eventdata, handles)