twohitfilters.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
#include <tracking/vxdCaTracking/TwoHitFilters.h>
#include <gtest/gtest.h>
 
namespace Belle2 {
  class TwoHitFiltersTest : public ::testing::Test {
  protected:
  };
 
  TEST_F(TwoHitFiltersTest, TestEmptyFilter)
  {
    TwoHitFilters aFilter = TwoHitFilters();
 
    EXPECT_DOUBLE_EQ(0., aFilter.calcDist3D());
 
    EXPECT_DOUBLE_EQ(0., aFilter.fullDist3D());
 
    EXPECT_DOUBLE_EQ(0., aFilter.calcDistXY());
 
    EXPECT_DOUBLE_EQ(0., aFilter.fullDistXY());
 
    EXPECT_DOUBLE_EQ(0., aFilter.calcDistZ());
 
    EXPECT_DOUBLE_EQ(0., aFilter.calcSlopeRZ());
 
    EXPECT_DOUBLE_EQ(0., aFilter.calcNormedDist3D());
 
    EXPECT_DOUBLE_EQ(42., aFilter.filterNan(42.));
 
    EXPECT_DOUBLE_EQ(42, aFilter.filterNan(42));
 
    EXPECT_DOUBLE_EQ(42., aFilter.filterNan(42));
 
    EXPECT_DOUBLE_EQ(0., aFilter.filterNan(1. / 0.));
 
  }
 
  TEST_F(TwoHitFiltersTest, TestFilledFilter)
  {
    B2Vector3D innerHit(1, 2, 3);
    B2Vector3D outerHit(2, 3, 4);
 
    TwoHitFilters aFilter = TwoHitFilters(outerHit, innerHit); // correct order
 
    EXPECT_DOUBLE_EQ(3., aFilter.calcDist3D()); // does calc dist (outer - innerHit)^2!
 
    EXPECT_DOUBLE_EQ(sqrt(3.), aFilter.fullDist3D()); // does calc dist (outer - innerHit)
 
    EXPECT_DOUBLE_EQ(2., aFilter.calcDistXY()); // does calc dist (outer - innerHit)^2!
 
    EXPECT_DOUBLE_EQ(sqrt(2.), aFilter.fullDistXY()); // does calc dist (outer - innerHit)calcDistXY
 
    EXPECT_DOUBLE_EQ(1., aFilter.calcDistZ());
 
    EXPECT_DOUBLE_EQ(atan(sqrt(2.)),
                     aFilter.calcSlopeRZ()); // normal slope is fullDistXY/calcDistZ = sqrt(2), here atan of slope is calculated
 
    EXPECT_DOUBLE_EQ(2. / 3., aFilter.calcNormedDist3D());
 
 
    TwoHitFilters bFilter =
      TwoHitFilters(); // initialising an empty filter first to check whether the resetting function is doing its job...
 
    bFilter.resetValues(innerHit, outerHit); // wrong order
 
    EXPECT_DOUBLE_EQ(aFilter.calcDist3D(), bFilter.calcDist3D()); // does calc dist (outer - innerHit)^2!
 
    EXPECT_DOUBLE_EQ(aFilter.fullDist3D(), bFilter.fullDist3D()); // does calc dist (outer - innerHit)
 
    EXPECT_DOUBLE_EQ(aFilter.calcDistXY(), bFilter.calcDistXY()); // does calc dist (outer - innerHit)^2!
 
    EXPECT_DOUBLE_EQ(aFilter.fullDistXY(), bFilter.fullDistXY()); // does calc dist (outer - innerHit)
 
    EXPECT_DOUBLE_EQ(-aFilter.calcDistZ(), bFilter.calcDistZ());
 
    EXPECT_DOUBLE_EQ(-aFilter.calcSlopeRZ(), bFilter.calcSlopeRZ());
 
    EXPECT_DOUBLE_EQ(aFilter.calcNormedDist3D(), bFilter.calcNormedDist3D());
  }
 
 
 
  TEST_F(TwoHitFiltersTest, testLargeFilter)
  {
    B2Vector3D innerHit(1e150, 0, 0);
    B2Vector3D outerHit(0, 0, 0);
    B2Vector3D innerHit2(1, 2, 3);
    B2Vector3D outerHit2(2, 3, 4);
 
    TwoHitFilters aFilter = TwoHitFilters(outerHit, innerHit); // correct order
 
    EXPECT_DOUBLE_EQ(1e300, aFilter.calcDist3D()); // does calc dist (outer - innerHit)^2!
 
    aFilter.resetValues(innerHit2, outerHit2);
 
    // does currently give an error at the clang-build:
//     EXPECT_DOUBLE_EQ(-atan(sqrt(2.)), aFilter.calcSlopeRZ());
  }
 
 
  TEST_F(TwoHitFiltersTest, testOutOfRangeFilter) //approx 1.8e308 ... largest possible value of a double
  {
    B2Vector3D innerHit(1e300, 0, 0);
    B2Vector3D outerHit(0, 0, 0);
 
    TwoHitFilters aFilter = TwoHitFilters(outerHit, innerHit); // correct order
 
//     EXPECT_DOUBLE_EQ(1e600, aFilter.calcDist3D()); // does calc dist (outer - innerHit)^2!
    EXPECT_DOUBLE_EQ(innerHit * innerHit, aFilter.calcDist3D()); // does calc dist (outer - innerHit)^2!
 
  }
 
  TEST_F(TwoHitFiltersTest,
         TestOutOfRangeNormedDistFilter) //FAILS, because both calcDistXY() and calcDist3D() are too large to be stored in a double.
  {
    B2Vector3D innerHit(1e300, 0, 1e300);
    B2Vector3D outerHit(0, 0, 0);
    double correctResult = 1. / 2.; // this should be the result which is analytically correct
    double wrongResult = 0.; // this is the result because of out of range of double precission
 
    TwoHitFilters aFilter = TwoHitFilters(outerHit, innerHit); // correct order
 
    // however, the values exceed the range of double, therefore the result is NOT EQUAL to the correct value:
    EXPECT_NE(correctResult, aFilter.calcNormedDist3D());
    EXPECT_DOUBLE_EQ(wrongResult, aFilter.calcNormedDist3D());
  }
}  // namespace