File: complete_filter_test.cpp

package info (click to toggle)
orocos-bfl 0.8.0-7
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 2,052 kB
  • sloc: cpp: 14,358; sh: 89; makefile: 8; ansic: 4
file content (466 lines) | stat: -rw-r--r-- 19,600 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
// Copyright (C) 2007 Wim Meeussen <wim DOT meeussen AT mech DOT kuleuven DOT be>
// Copyright (C) 2008 Tinne De Laet <tinne DOT delaet AT mech DOT kuleuven DOT be>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//


#include "complete_filter_test.hpp"
#include "approxEqual.hpp"




// Registers the fixture into the 'registry'
CPPUNIT_TEST_SUITE_REGISTRATION( Complete_FilterTest );

using namespace MatrixWrapper;
using namespace BFL;


void
Complete_FilterTest::setUp()
{
}


void
Complete_FilterTest::tearDown()
{
}

void
Complete_FilterTest::testComplete_FilterValue_Cont()
{
  double epsilon       = 0.015;
  double epsilon_large = 0.5;
  double epsilon_huge  = 2.0;

  /****************************
   * Initialise system model *
   ***************************/
  ColumnVector SysNoise_Mu(STATE_SIZE);
  SysNoise_Mu = 0.0;
  SysNoise_Mu(1) = MU_SYSTEM_NOISE_X;
  SysNoise_Mu(2) = MU_SYSTEM_NOISE_Y;
  SysNoise_Mu(3) = MU_SYSTEM_NOISE_THETA;

  SymmetricMatrix SysNoise_Cov(STATE_SIZE);
  SysNoise_Cov = 0.0;
  // Uncertainty or Noice (Additive) and Matrix A
  SysNoise_Cov(1,1) = SIGMA_SYSTEM_NOISE_X;
  SysNoise_Cov(2,2) = SIGMA_SYSTEM_NOISE_Y;
  SysNoise_Cov(3,3) = SIGMA_SYSTEM_NOISE_THETA;

  Gaussian System_Uncertainty(SysNoise_Mu, SysNoise_Cov);
  NonLinearAnalyticConditionalGaussianMobile sys_pdf(System_Uncertainty);
  AnalyticSystemModelGaussianUncertainty sys_model(&sys_pdf);


  /*********************************
   * Initialise measurement model *
   ********************************/
  // Fill up H
  double wall_ct = 2/(sqrt(pow(RICO_WALL,2.0) + 1));
  Matrix H(MEAS_SIZE,STATE_SIZE);
  H = 0.0;
  H(1,1) = wall_ct * RICO_WALL;
  H(1,2) = 0 - wall_ct;

  // Construct the measurement noise (a scalar in this case)
  ColumnVector MeasNoise_Mu(MEAS_SIZE);
  SymmetricMatrix MeasNoise_Cov(MEAS_SIZE);
  MeasNoise_Mu(1) = MU_MEAS_NOISE;
  MeasNoise_Cov(1,1) = SIGMA_MEAS_NOISE;

  Gaussian Measurement_Uncertainty(MeasNoise_Mu,MeasNoise_Cov);
  LinearAnalyticConditionalGaussian meas_pdf(H,Measurement_Uncertainty);
  LinearAnalyticMeasurementModelGaussianUncertainty meas_model(&meas_pdf);

  /****************************
   * Initialise prior DENSITY *
   ***************************/
  // Continuous Gaussian prior (for Kalman filters)
  ColumnVector prior_mu(STATE_SIZE);
  SymmetricMatrix prior_sigma(STATE_SIZE);
  prior_mu(1) = PRIOR_MU_X;
  prior_mu(2) = PRIOR_MU_Y;
  prior_mu(STATE_SIZE) = PRIOR_MU_THETA;
  prior_sigma = 0.0;
  prior_sigma(1,1) = PRIOR_COV_X;
  prior_sigma(2,2) = PRIOR_COV_Y;
  prior_sigma(3,3) = PRIOR_COV_THETA;
  Gaussian prior_cont(prior_mu,prior_sigma);

  // Discrete prior for Particle filter (using the continuous Gaussian prior)
  vector<Sample<ColumnVector> > prior_samples(NUM_SAMPLES);
  MCPdf<ColumnVector> prior_discr(NUM_SAMPLES,STATE_SIZE);
  prior_cont.SampleFrom(prior_samples,NUM_SAMPLES,CHOLESKY,NULL);
  prior_discr.ListOfSamplesSet(prior_samples);

  // Mixture prior for the Mixture Boostrap filter
  ColumnVector prior_mu1(STATE_SIZE);
  SymmetricMatrix prior_sigma1(STATE_SIZE);
  prior_mu1(1) = PRIOR_MU_X1;
  prior_mu1(2) = PRIOR_MU_Y1;
  prior_mu1(STATE_SIZE) = PRIOR_MU_THETA1;
  prior_sigma1 = 0.0;
  prior_sigma1(1,1) = PRIOR_COV_X1;
  prior_sigma1(2,2) = PRIOR_COV_Y1;
  prior_sigma1(3,3) = PRIOR_COV_THETA1;
  Gaussian prior_cont1(prior_mu1,prior_sigma1);

  MCPdf<ColumnVector> mixcomp1(NUM_SAMPLES,STATE_SIZE);
  prior_cont1.SampleFrom(prior_samples,NUM_SAMPLES,CHOLESKY,NULL);
  mixcomp1.ListOfSamplesSet(prior_samples);

  ColumnVector prior_mu2(STATE_SIZE);
  SymmetricMatrix prior_sigma2(STATE_SIZE);
  prior_mu2(1) = PRIOR_MU_X2;
  prior_mu2(2) = PRIOR_MU_Y2;
  prior_mu2(STATE_SIZE) = PRIOR_MU_THETA2;
  prior_sigma2 = 0.0;
  prior_sigma2(1,1) = PRIOR_COV_X2;
  prior_sigma2(2,2) = PRIOR_COV_Y2;
  prior_sigma2(3,3) = PRIOR_COV_THETA2;
  Gaussian prior_cont2(prior_mu2,prior_sigma2);

  MCPdf<ColumnVector> mixcomp2(NUM_SAMPLES,STATE_SIZE);
  prior_cont2.SampleFrom(prior_samples,NUM_SAMPLES,CHOLESKY,NULL);
  mixcomp2.ListOfSamplesSet(prior_samples);

  ColumnVector prior_mu3(STATE_SIZE);
  SymmetricMatrix prior_sigma3(STATE_SIZE);
  prior_mu3(1) = PRIOR_MU_X3;
  prior_mu3(2) = PRIOR_MU_Y3;
  prior_mu3(STATE_SIZE) = PRIOR_MU_THETA3;
  prior_sigma3 = 0.0;
  prior_sigma3(1,1) = PRIOR_COV_X3;
  prior_sigma3(2,2) = PRIOR_COV_Y3;
  prior_sigma3(3,3) = PRIOR_COV_THETA3;
  Gaussian prior_cont3(prior_mu3,prior_sigma3);

  MCPdf<ColumnVector> mixcomp3(NUM_SAMPLES,STATE_SIZE);
  prior_cont3.SampleFrom(prior_samples,NUM_SAMPLES,CHOLESKY,NULL);
  mixcomp3.ListOfSamplesSet(prior_samples);

  ColumnVector prior_mu4(STATE_SIZE);
  SymmetricMatrix prior_sigma4(STATE_SIZE);
  prior_mu4(1) = PRIOR_MU_X4;
  prior_mu4(2) = PRIOR_MU_Y4;
  prior_mu4(STATE_SIZE) = PRIOR_MU_THETA3;
  prior_sigma4 = 0.0;
  prior_sigma4(1,1) = PRIOR_COV_X4;
  prior_sigma4(2,2) = PRIOR_COV_Y4;
  prior_sigma4(3,3) = PRIOR_COV_THETA4;
  Gaussian prior_cont4(prior_mu4,prior_sigma4);

  MCPdf<ColumnVector> mixcomp4(NUM_SAMPLES,STATE_SIZE);
  prior_cont4.SampleFrom(prior_samples,NUM_SAMPLES,CHOLESKY,NULL);
  mixcomp4.ListOfSamplesSet(prior_samples);

  vector<Pdf<ColumnVector>*> mixVec(3);
  mixVec[0] = &mixcomp1;
  mixVec[1] = &mixcomp2;
  mixVec[2] = &mixcomp3;
  //mixVec[3] = &mixcomp4;
  Mixture<ColumnVector> prior_mix(mixVec);

  // check
  ColumnVector mean_check(STATE_SIZE);
  mean_check(1) = PRIOR_MU_X; mean_check(2) = PRIOR_MU_Y; mean_check(3) = PRIOR_MU_THETA;
  SymmetricMatrix cov_check(STATE_SIZE);
  cov_check(1,1) = PRIOR_COV_X; cov_check(1,2) = 0; cov_check(1,3) = 0;
  cov_check(2,1) = 0; cov_check(2,2) = PRIOR_COV_Y; cov_check(2,3) = 0;
  cov_check(3,1) = 0; cov_check(3,2) = 0; cov_check(3,3) = PRIOR_COV_THETA;
  CPPUNIT_ASSERT_EQUAL(approxEqual(prior_cont.ExpectedValueGet(), mean_check, epsilon),true);
  CPPUNIT_ASSERT_EQUAL(approxEqual(prior_cont.CovarianceGet(), cov_check, epsilon),true);


  /***************************
   * initialise MOBILE ROBOT *
   **************************/
  // Model of mobile robot in world
  // The model is used to simultate the distance measurements.
  MobileRobot mobile_robot;
  ColumnVector input(INPUT_SIZE);
  input(1) = LIN_SPEED * DELTA_T;
  input(2)  = ROT_SPEED * DELTA_T;


  /******************************
   * Construction of the Filter *
   ******************************/
  Filter<ColumnVector,ColumnVector> *my_filter_extendedkalman, *my_filter_iteratedextendedkalman, *my_filter_bootstrap, *my_filter_ekparticle, *my_filter_mixtureBootstrap;
  my_filter_extendedkalman = new ExtendedKalmanFilter(&prior_cont);
  my_filter_iteratedextendedkalman = new IteratedExtendedKalmanFilter(&prior_cont,NUM_ITERATIONS);
  my_filter_bootstrap = new BootstrapFilter<ColumnVector,ColumnVector> (&prior_discr, RESAMPLE_PERIOD, RESAMPLE_THRESHOLD);
  my_filter_ekparticle = new EKParticleFilter(&prior_discr, 0, RESAMPLE_THRESHOLD);
  my_filter_mixtureBootstrap = new MixtureBootstrapFilter<ColumnVector,ColumnVector> (&prior_mix, RESAMPLE_PERIOD, RESAMPLE_THRESHOLD);

  /*******************
   * ESTIMATION LOOP *
   *******************/
  ColumnVector measurement ;
  ColumnVector mobile_robot_state ;
  Pdf<ColumnVector> * posterior_mixtureBootstrap;
  ofstream mixtureFile;
  if(OUTPUT_MIXTURE)
  {
    mixtureFile.open("mixtureOutput.txt");
  }

  cout << "Running 4 different filters. This may take a few minutes... " << endl;
  unsigned int time_step;
  for (time_step = 0; time_step < NUM_TIME_STEPS-1; time_step++)
    {
      // DO ONE STEP WITH MOBILE ROBOT
      mobile_robot.Move(input);

      // DO ONE MEASUREMENT
      measurement = mobile_robot.Measure();
      mobile_robot_state = mobile_robot.GetState();

      if(OUTPUT_MIXTURE)
      {
        posterior_mixtureBootstrap = my_filter_mixtureBootstrap->PostGet();
        vector<WeightedSample<ColumnVector> > los;
        vector<WeightedSample<ColumnVector> >::iterator los_it;
        int numComp = dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->NumComponentsGet();
        mixtureFile << time_step << " " << numComp << " ";  
        mixtureFile << mobile_robot_state(1) << " " << mobile_robot_state(2) << " " << mobile_robot_state(3) << " ";  
        for(int i = 0 ; i<numComp ; i++ )
        {   
            double componentWeight = ( dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->WeightGet(i)) ;
            los = dynamic_cast<MCPdf<ColumnVector> *>( dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->ComponentGet(i))->ListOfSamplesGet(); 
            mixtureFile << i << " " << componentWeight << " " << los.size()<< " " << STATE_SIZE << " ";  
            for ( los_it=los.begin(); los_it != los.end() ; los_it++)
            {
                for (int j=0; j<STATE_SIZE ; j++)
                    mixtureFile << los_it->ValueGet()[j] << " ";
                mixtureFile<< los_it->WeightGet() << " ";  
            } 
        }
        mixtureFile<<endl;
       }
      // UPDATE FILTER
      my_filter_extendedkalman->Update(&sys_model,input,&meas_model, measurement);
      my_filter_iteratedextendedkalman->Update(&sys_model,input,&meas_model, measurement);
      my_filter_bootstrap->Update(&sys_model,input,&meas_model, measurement);
      //my_filter_ekparticle->Update(&sys_model,input,&meas_model, measurement);
      my_filter_mixtureBootstrap->Update(&sys_model,input,&meas_model, measurement);
    }

    if(OUTPUT_MIXTURE)
    {
      posterior_mixtureBootstrap = my_filter_mixtureBootstrap->PostGet();
      vector<WeightedSample<ColumnVector> > los;
      vector<WeightedSample<ColumnVector> >::iterator los_it;
      int numComp = dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->NumComponentsGet();
      mixtureFile << time_step << " " << numComp << " ";  
      mixtureFile << mobile_robot_state(1) << " " << mobile_robot_state(2) << " " << mobile_robot_state(3) << " ";  
      for(int i = 0 ; i<numComp ; i++ )
      {   
          double componentWeight = ( dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->WeightGet(i)) ;
          los = dynamic_cast<MCPdf<ColumnVector> *>( dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->ComponentGet(i))->ListOfSamplesGet(); 
          mixtureFile << i << " " << componentWeight << " " << los.size()<< " " << STATE_SIZE << " ";  
          for ( los_it=los.begin(); los_it != los.end() ; los_it++)
          {
              for (int j=0; j<STATE_SIZE ; j++)
                  mixtureFile << los_it->ValueGet()[j] << " ";
              mixtureFile<< los_it->WeightGet() << " ";  
          } 
      }
      mixtureFile<<endl;
     }


  // ek_check
  Pdf<ColumnVector> * posterior_extendedkalman = my_filter_extendedkalman->PostGet();
  ColumnVector mean_ek_check(STATE_SIZE);
  mean_ek_check=mobile_robot.GetState();
  //mean_ek_check(1) = mobile_robot_state(1); mean_ek_check(2) = mobile_robot_state(2); mean_ek_check(3) = mobile_robot_state(3);
  SymmetricMatrix cov_ek_check(STATE_SIZE);
  cov_ek_check(1,1) = 0.0599729;   cov_ek_check(1,2) = 0.000291386; cov_ek_check(1,3) = 0.00223255;
  cov_ek_check(2,1) = 0.000291386; cov_ek_check(2,2) = 0.000277528; cov_ek_check(2,3) = 0.000644136;
  cov_ek_check(3,1) = 0.00223255;  cov_ek_check(3,2) = 0.000644136; cov_ek_check(3,3) = 0.00766009;
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_extendedkalman->ExpectedValueGet(), mean_ek_check, epsilon_large),true);
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_extendedkalman->CovarianceGet(), cov_ek_check, epsilon),true);

  // it_check
  Pdf<ColumnVector> * posterior_iteratedextendedkalman = my_filter_iteratedextendedkalman->PostGet();
  ColumnVector mean_it_check(STATE_SIZE);
  mean_it_check=mobile_robot.GetState();
  //mean_it_check(1) = mobile_robot_state(1); mean_it_check(2) = mobile_robot_state(2); mean_it_check(3) = mobile_robot_state(3);
  SymmetricMatrix cov_it_check(STATE_SIZE);
  cov_it_check = 0.0;
  cov_it_check(1,1) = 0.0611143;   cov_it_check(1,2) = 0.000315923; cov_it_check(1,3) = 0.00238938;
  cov_it_check(2,1) = 0.000315923; cov_it_check(2,2) = 0.000280736; cov_it_check(2,3) = 0.000665735;
  cov_it_check(3,1) = 0.00238938;  cov_it_check(3,2) = 0.000665735; cov_it_check(3,3) = 0.00775776;
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_iteratedextendedkalman->ExpectedValueGet(), mean_it_check, epsilon_large),true);
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_iteratedextendedkalman->CovarianceGet(), cov_it_check, epsilon),true);

  // bs_check
  Pdf<ColumnVector> * posterior_bootstrap = my_filter_bootstrap->PostGet();
  ColumnVector mean_bs_check(STATE_SIZE);
  mean_bs_check=mobile_robot.GetState();
  //mean_bs_check(1) = mobile_robot_state(1); mean_bs_check(2) = mobile_robot_state(2); mean_bs_check(3) = mobile_robot_state(3);
  SymmetricMatrix cov_bs_check(STATE_SIZE);
  cov_bs_check = 0.0;
  cov_bs_check(1,1) = PRIOR_COV_X;   
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_bootstrap->ExpectedValueGet(), mean_bs_check, epsilon_large),true);
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_bootstrap->CovarianceGet(), cov_bs_check, epsilon),true);

  // ep_check
  /*
  Pdf<ColumnVector> * posterior_ekparticle = my_filter_ekparticle->PostGet();
  cout << " Posterior Mean = " << endl << posterior_ekparticle->ExpectedValueGet() << endl
       << " Covariance = " << endl << posterior_ekparticle->CovarianceGet() << "" << endl;
  ColumnVector mean_ep_check(STATE_SIZE);
  //mean_ep_check(1) = 6.64581; mean_ep_check(2) = -7.05499; mean_ep_check(3) = -0.76974;
  mean_ep_check=mobile_robot.GetState();
  SymmetricMatrix cov_ep_check(STATE_SIZE);
  cov_ep_check(1,1) = 0.0160492;   cov_ep_check(1,2) = 0.000193798; cov_ep_check(1,3) = 0.0013101;
  cov_ep_check(2,1) = 0.000193798; cov_ep_check(2,2) = 0.000289425; cov_ep_check(2,3) = 0.000701263;
  cov_ep_check(3,1) = 0.0013101;   cov_ep_check(3,2) = 0.000701263; cov_ep_check(3,3) = 0.00682061;
  cout << "mean_ep_check " << mean_ep_check << endl;
  cout << "cov_ep_check " << cov_ep_check << endl;
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_ekparticle->ExpectedValueGet(), mean_ep_check, epsilon_huge),true);
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_ekparticle->CovarianceGet(), cov_ep_check, epsilon_large),true);
  */
  // mixtureBoostrapFilter check
  posterior_mixtureBootstrap = my_filter_mixtureBootstrap->PostGet();
  ColumnVector mean_mbs_check(STATE_SIZE);
  //mean_mbs_check(1) = 6.64581; mean_mbs_check(2) = -7.05499; mean_mbs_check(3) = -0.76974;
  mean_mbs_check(1) = mobile_robot_state(1); mean_mbs_check(2) = mobile_robot_state(2); mean_mbs_check(3) = mobile_robot_state(3);
  //cout << "mixture weights:" << endl;
  vector<Probability> weights= dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->WeightsGet();
  ColumnVector exp;
  for(int i = 0 ; i< dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->NumComponentsGet(); i++ )
  {
        //cout << "weight component " << i << ": " << weights[i] << endl;
        exp= dynamic_cast<Mixture<ColumnVector> *>(posterior_mixtureBootstrap)->ComponentGet(i)->ExpectedValueGet();
        //cout << "expected value component " << i << ": " << exp << endl;
  }
  //cout << "expected value total: " << posterior_mixtureBootstrap->ExpectedValueGet() << endl;
  //cout << "should be : " << mean_mbs_check << endl;
  CPPUNIT_ASSERT_EQUAL(approxEqual(posterior_mixtureBootstrap->ExpectedValueGet(), mean_mbs_check, epsilon_huge),true);

  // closing file stream
  if(OUTPUT_MIXTURE)
  {
    mixtureFile.close();
  }

  // delete the filters
  delete my_filter_extendedkalman;
  delete my_filter_iteratedextendedkalman;
  delete my_filter_bootstrap;
  delete my_filter_ekparticle;
  delete my_filter_mixtureBootstrap;
}

void
Complete_FilterTest::testComplete_FilterValue_Discr()
{
  int num_states = 20;
  int num_cond_args = 1;
  /****************************
  * Discrete system model      *
  ***************************/
  int cond_arg_dims[num_cond_args];
  cond_arg_dims[0] = num_states;
  DiscreteConditionalPdf sys_pdf(num_states,num_cond_args,cond_arg_dims);  // no  inputs
  std::vector<int> cond_args(num_cond_args);
  double prob_diag = 0.9;
  double prob_nondiag = (1-prob_diag)/(num_states-1);
  for (int state_kMinusOne = 0 ; state_kMinusOne < num_states ;  state_kMinusOne++)
    {
       cond_args[0] = state_kMinusOne;
       for (int state_k = 0 ; state_k < num_states ;  state_k++)
         {
           if (state_kMinusOne == state_k) sys_pdf.ProbabilitySet(prob_diag,state_k,cond_args);
           else sys_pdf.ProbabilitySet(prob_nondiag,state_k,cond_args);
         }
    }
  DiscreteSystemModel sys_model(&sys_pdf);

  /*********************************
   * Initialise measurement model *
   ********************************/

  // Construct the measurement noise (a scalar in this case)
  ColumnVector measNoise_Mu(MEAS_SIZE);
  measNoise_Mu(1) = MU_MEAS_NOISE;

  SymmetricMatrix measNoise_Cov(MEAS_SIZE);
  measNoise_Cov(1,1) = SIGMA_MEAS_NOISE;
  Gaussian measurement_uncertainty(measNoise_Mu, measNoise_Cov);

  // create the model
  ConditionalUniformMeasPdf1d meas_pdf(measurement_uncertainty);
  MeasurementModel<MatrixWrapper::ColumnVector,int> meas_model(&meas_pdf);

  /****************************
  * Uniform prior DENSITY     *
  ***************************/
  DiscretePdf prior(num_states); //equal probability is set for all classed

  /******************************
   * Construction of the Filter *
   ******************************/
  HistogramFilter<ColumnVector> filter(&prior);
  DiscretePdf * prior_test = filter.PostGet();

  /***************************
   * initialise MOBILE ROBOT *
   **************************/
  // Model of mobile robot in world with one wall
  // The model is used to simultate the distance measurements.
  MobileRobot mobile_robot;
  ColumnVector input(2);
  input(1) = 0.1;
  input(2) = 0.0;


  /*******************
   * ESTIMATION LOOP *
   *******************/
  unsigned int time_step;
  for (time_step = 0; time_step < NUM_TIME_STEPS-1; time_step++)
    {
      // DO ONE STEP WITH MOBILE ROBOT
      mobile_robot.Move(input);
      // DO ONE MEASUREMENT
      ColumnVector measurement = mobile_robot.Measure();
      // change sign of measurement (measurement model returns negative value)
      measurement(1) = 0-measurement(1);
      // UPDATE FILTER
      filter.Update(&sys_model,&meas_model,measurement);
    } // estimation loop

  // FIXME: This test needs more explanation...
  DiscretePdf *  posterior = filter.PostGet();
  for (int state=0; state< num_states; state++)
  {
    // std::cout << "state = " << state << " : " << "posterior->ProbabilityGet(state) = " << posterior->ProbabilityGet(state) << std::endl;
    if (state == (int)(round(mobile_robot.GetState()(2))) ){ // Y position  What does this comparison mean???
      CPPUNIT_ASSERT(posterior->ProbabilityGet(state) >0.9);
    }
    else {
      CPPUNIT_ASSERT(posterior->ProbabilityGet(state) <0.1);
    }
  }
}