public void testGetCoordinatesBetween() {

    try {
      // what if the null value is passed
      CoordinateSequence[] cs = nullLine.getCoordinatesBetween(0.0, 5.0);
      assertTrue("cs.length = " + cs.length + ". Should be 1", cs.length == 1);
      assertEquals(cs[0].size(), 0);

      arbitraryLine.measureOnLength(false);
      // what if from/to is outside of the range of values
      double maxM = arbitraryLine.getMaxM();
      cs = arbitraryLine.getCoordinatesBetween(maxM + 1.0, maxM + 10.0);

      // check for several ascending M-values
      int minIdx = (int) (Math.random() * (arbitraryLine.getNumPoints() - 1));
      int maxIdx = Math.min((arbitraryLine.getNumPoints() - 1), minIdx + 10);
      double minM = ((MCoordinate) arbitraryLine.getCoordinateN(minIdx)).m;
      maxM = ((MCoordinate) arbitraryLine.getCoordinateN(maxIdx)).m;
      cs = arbitraryLine.getCoordinatesBetween(minM, maxM);
      assertNotNull(cs);
      assertTrue(cs.length > 0);
      Coordinate[] coar = cs[0].toCoordinateArray();
      int j = 0;
      for (int i = minIdx; i <= maxIdx; i++) {
        assertEquals((MCoordinate) arbitraryLine.getCoordinateN(i), coar[j]);
        j++;
      }

      minM = Math.max(0.0, minM - Math.random() * 10);
      cs = arbitraryLine.getCoordinatesBetween(minM, maxM);
      coar = cs[0].toCoordinateArray();
      MCoordinate mctest = (MCoordinate) coar[0];
      MCoordinate mcexp = (MCoordinate) arbitraryLine.getCoordinateAtM(minM);
      assertEquals(mcexp, mctest);
      assertEquals(mctest.m, minM, DoubleComparator.defaultNumericalPrecision());

      maxM = Math.min(arbitraryLine.getLength(), maxM + Math.random() * 10);
      cs = arbitraryLine.getCoordinatesBetween(minM, maxM);
      coar = cs[0].toCoordinateArray();
      mctest = (MCoordinate) coar[coar.length - 1];
      mcexp = (MCoordinate) arbitraryLine.getCoordinateAtM(maxM);
      assertEquals(mcexp.x, mctest.x, Math.ulp(mcexp.x) * 100);
      assertEquals(mcexp.y, mctest.y, Math.ulp(mcexp.y) * 100);
      assertEquals(mctest.m, maxM, DoubleComparator.defaultNumericalPrecision());

    } catch (Exception e) {
      e.printStackTrace();
      assertTrue(false); // should never reach here
    }
  }
  public void testGetMatCoordinate() {
    try {
      // what in case of the null string
      assertTrue(Double.isNaN(nullLine.getMatCoordinate(new Coordinate(1.0, 1.0), 1.0)));

      // get two neighbouring points along the arbitraryline
      arbitraryLine.measureOnLength(false);
      int elem1Indx = (int) (Math.random() * (arbitraryLine.getNumPoints() - 1));
      int elem2Indx = 0;
      if (elem1Indx == arbitraryLine.getNumPoints() - 1) {
        elem2Indx = elem1Indx - 1;
      } else {
        elem2Indx = elem1Indx + 1;
      }

      // if a coordinate of the geometry is passed, it should return
      // exactly that m-value
      MCoordinate mco1 = (MCoordinate) arbitraryLine.getCoordinateN(elem1Indx);
      double m = arbitraryLine.getMatCoordinate(mco1, 0.00001);
      assertEquals(mco1.m, m, DoubleComparator.defaultNumericalPrecision());

      // check for a coordinate between mco1 and mco2 (neighbouring
      // coordinates)
      MCoordinate mco2 = (MCoordinate) arbitraryLine.getCoordinateN(elem2Indx);
      double offset = Math.random();
      double expectedM = mco1.m + offset * (mco2.m - mco1.m);
      Coordinate mctest =
          new Coordinate(mco1.x + offset * (mco2.x - mco1.x), mco1.y + offset * (mco2.y - mco1.y));

      double testM = arbitraryLine.getMatCoordinate(mctest, offset);
      assertEquals(expectedM, testM, DoubleComparator.defaultNumericalPrecision());
    } catch (Exception e) {
      e.printStackTrace();
      assertTrue(false); // should never reach here
    }
  }
  public void testGetClosestPoint() {

    try {
      if (!arbitraryLine.isMonotone(false)) {
        Coordinate mc = arbitraryLine.getClosestPoint(new Coordinate(1.0, 2.0), 0.1);
        assertTrue(false); // should never evaluate this
      }
    } catch (Exception e) {
      assertTrue(
          ((MGeometryException) e).getType() == MGeometryException.OPERATION_REQUIRES_MONOTONE);
    }

    try {
      // check reaction on null string
      MCoordinate mc = nullLine.getClosestPoint(new Coordinate(0.0, 1.0), 1.0);
      assertNull(mc);

      // must return the very same coordinate if the coordinate is a
      // coordinate of the line
      arbitraryLine.measureOnLength(false);
      int selp = (int) (arbitraryLine.getNumPoints() / 2);
      MCoordinate mcexp = (MCoordinate) arbitraryLine.getCoordinateN(selp);
      MCoordinate mctest = arbitraryLine.getClosestPoint(mcexp, 1);
      assertEquals(mcexp, mctest);

      // must not return a point that is beyond the tolerance
      mctest = controlledLine.getClosestPoint(new Coordinate(20.0, 20, 0), 1.0);
      assertNull(mctest);

      // check for cases of circular MGeometry: lowest measure should be
      // return.
      ringLine.measureOnLength(false);
      assertTrue(ringLine.isRing());
      assertTrue(ringLine.isMonotone(false));
      assertTrue(ringLine.getMeasureDirection() == MGeometry.INCREASING);
      MCoordinate expCo = MCoordinate.create2dWithMeasure(0.0, 0.0, 0.0);
      MCoordinate testCo = ringLine.getClosestPoint(expCo, 0.1);
      assertTrue(DoubleComparator.equals(testCo.m, expCo.m));
      ringLine.reverseMeasures();
      testCo = ringLine.getClosestPoint(expCo, 0.1);
      assertTrue(DoubleComparator.equals(testCo.m, expCo.m));
      ringLine.measureOnLength(false);
      int n = ringLine.getNumPoints() - 1;
      ringLine.setMeasureAtIndex(n, 100.0);
      ringLine.setMeasureAtIndex(0, 0.0);
      testCo = ringLine.getClosestPoint(expCo, 0.001);
      assertTrue(DoubleComparator.equals(testCo.m, 0.0));

      // get two neighbouring points along the arbitraryline
      arbitraryLine.measureOnLength(false);
      int elem1Indx = (int) (Math.random() * (arbitraryLine.getNumPoints() - 1));
      int elem2Indx = 0;
      if (elem1Indx == arbitraryLine.getNumPoints() - 1) {
        elem2Indx = elem1Indx - 1;
      } else {
        elem2Indx = elem1Indx + 1;
      }
      // testsuite-suite whether a coordinate between these two returns exactly
      MCoordinate mco1 = (MCoordinate) arbitraryLine.getCoordinateN(elem1Indx);
      MCoordinate mco2 = (MCoordinate) arbitraryLine.getCoordinateN(elem2Indx);
      double d = mco1.distance(mco2);
      double offset = Math.random();
      mcexp =
          MCoordinate.create2dWithMeasure(
              mco1.x + offset * (mco2.x - mco1.x), mco1.y + offset * (mco2.y - mco1.y), 0.0);
      mctest = arbitraryLine.getClosestPoint(mcexp, d);
      mcexp.m = mco1.m + offset * (mco2.m - mco1.m);
      assertEquals(mcexp.x, mctest.x, 0.001);
      assertEquals(mcexp.y, mctest.y, 0.001);
      assertEquals(mcexp.z, mctest.z, 0.001);
      double delta = Math.random();

      MCoordinate mcin =
          MCoordinate.create2dWithMeasure(
              mco1.x + offset * (mco2.x - mco1.x) + delta,
              mco1.y + offset * (mco2.y - mco1.y) + delta,
              0.0);

      // returned point is on the line
      mctest = arbitraryLine.getClosestPoint(mcin, d);
      assertEquals(mcin.x, mctest.x, delta * Math.sqrt(2));
      assertEquals(mcin.y, mctest.y, delta * Math.sqrt(2));
    } catch (Exception e) {
      e.printStackTrace();
      assertTrue(false); // should never reach this point
    }
  }