How to use

BursaWolfParameters

in

org.apache.sis.referencing.datum

/**
 * {@inheritDoc}
 *
 * @return {@code true} if the parameters describe no operation.
 */
@Override
public boolean isIdentity() {
  return super.isIdentity() && dtX == 0 && dtY == 0 && dtZ == 0;
}

/**
 * Returns {@code true} if a transformation built from this set of parameters would perform no operation.
 * This is true when the value of all parameters is zero.
 *
 * @return {@code true} if the parameters describe no operation.
 */
public boolean isIdentity() {
  return tX == 0 && tY == 0 && tZ == 0 && isTranslation();
}

/**
 * Creates the {@code TOWGS84} element during parsing of a WKT version 1.
 *
 * @param  values  the 7 Bursa-Wolf parameter values.
 * @return the {@link BursaWolfParameters}.
 *
 * @since 0.6
 */
@Override
public Object createToWGS84(final double[] values) {
  final BursaWolfParameters info = new BursaWolfParameters(CommonCRS.WGS84.datum(), null);
  info.setValues(values);
  return info;
}

/**
 * Inverts in-place the transformation by inverting the sign of all numerical parameters.
 * The {@linkplain #getPositionVectorTransformation(Date) position vector transformation} matrix
 * created from inverted Bursa-Wolf parameters will be <strong>approximatively</strong> equals
 * to the {@linkplain org.apache.sis.referencing.operation.matrix.MatrixSIS#inverse() inverse}
 * of the matrix created from the original parameters. The equality holds approximatively only
 * because the parameter values are very small (parts per millions and arc-seconds).
 */
public void invert() {
  final double[] values = getValues();
  for (int i=0; i<values.length; i++) {
    values[i] = -values[i];
  }
  setValues(values);
}

/**
 * Returns the parameters for the <cite>WGS 72 to WGS 84 (2)</cite> transformation (EPSG:1238).
 * Area of validity is the World.
 */
static BursaWolfParameters createWGS72_to_WGS84() {
  final BursaWolfParameters bursaWolf = new BursaWolfParameters(GeodeticDatumMock.WGS84, Extents.WORLD);
  bursaWolf.tZ = 4.5;
  bursaWolf.rZ = 0.554;
  bursaWolf.dS = 0.219;
  bursaWolf.verify(PrimeMeridianMock.GREENWICH);
  assertFalse("isIdentity",    bursaWolf.isIdentity());
  assertFalse("isTranslation", bursaWolf.isTranslation());
  return bursaWolf;
}

/**
 * Tests the {@link BursaWolfParameters#setPositionVectorTransformation(Matrix, double)} method.
 * This is an internal consistency test.
 */
@Test
@DependsOnMethod("testGetPositionVectorTransformation")
public void testSetPositionVectorTransformation() {
  final BursaWolfParameters bursaWolf = createED87_to_WGS84();
  final Matrix matrix = bursaWolf.getPositionVectorTransformation(null);
  final BursaWolfParameters actual = new BursaWolfParameters(
      bursaWolf.getTargetDatum(), bursaWolf.getDomainOfValidity());
  actual.setPositionVectorTransformation(matrix, 1E-10);
  assertEquals(bursaWolf, actual);
}

final BursaWolfParameters parameters = new BursaWolfParameters(null, null);
try {
  parameters.setPositionVectorTransformation(((LinearTransform) step).getMatrix(), BURSAWOLF_TOLERANCE);
} catch (IllegalArgumentException e) {
  continue;
final boolean isTranslation = parameters.isTranslation();
final Parameters values = createParameters(isTranslation ? GeocentricTranslation.PARAMETERS
            : PositionVector7Param.PARAMETERS, parameters, isTranslation);

final double[] values = getValues();
for (final double value : values) {
  formatter.append(value);
if (isToWGS84()) {
  if (values.length > 7) {
    formatter.setInvalidWKT(BursaWolfParameters.class, null);
String name = IdentifiedObjects.getUnicodeIdentifier(getTargetDatum());
if (name == null) {
  name = "Unknown";

if (datum instanceof DefaultGeodeticDatum) {
  for (final BursaWolfParameters bwp : ((DefaultGeodeticDatum) datum).getBursaWolfParameters()) {
    if (Utilities.equalsIgnoreMetadata(CommonCRS.WGS84.datum(), bwp.getTargetDatum())) {
      definition.append(" +towgs84=").append(bwp.tX).append(',').append(bwp.tY).append(',').append(bwp.tZ);
      if (!bwp.isTranslation()) {
        definition.append(',').append(bwp.rX).append(',').append(bwp.rY).append(',').append(bwp.rZ).append(',').append(bwp.dS);

/**
 * Returns the best parameters matching the given criteria, or {@code null} if none.
 */
private BursaWolfParameters select(final GeodeticDatum targetDatum, final ExtentSelector<BursaWolfParameters> selector) {
  if (bursaWolf == null) {
    return null;
  }
  for (final BursaWolfParameters candidate : bursaWolf) {
    if (deepEquals(targetDatum, candidate.getTargetDatum(), ComparisonMode.IGNORE_METADATA)) {
      selector.evaluate(candidate.getDomainOfValidity(), candidate);
    }
  }
  return selector.best();
}

/**
 * Tests {@link BursaWolfParameters#setValues(double[])}.
 */
@Test
@DependsOnMethod("testGetValues")
public void testSetValues() {
  final BursaWolfParameters actual =  createWGS72_to_WGS84();
  final BursaWolfParameters expected = createED87_to_WGS84();
  final double[] values = expected.getValues();
  assertFalse("equals(Object) before to set the values.", actual.equals(expected));
  actual.setValues(values);
  assertArrayEquals("getValues() after setting the values.", values, actual.getValues(), STRICT);
  // Can not test assertEquals(expected, actual) because of different geographic extent.
}

/**
 * Tests the conversion from {@code CompoundCRS[EPSG:3035 + Sigma-level]} to {@code EPSG:4326}.
 * The interesting part in this test is that the height is not a standard height, and the
 * referencing module is not supposed to known how to build a 3D Geographic CRS (needed as
 * an intermediate step for the datum shift) with that height.
 *
 * @throws FactoryException Should never happen.
 *
 * @see <a href="http://jira.geotoolkit.org/browse/GEOTK-71">GEOTK-71</a>
 */
@Test
@Ignore("JSR-275 does not accept unit named 'level'.")
public void testProjected3D_to_2D() throws FactoryException {
  CoordinateReferenceSystem targetCRS = CommonCRS.WGS84.geographic();
  CoordinateReferenceSystem sourceCRS = CRS.forCode("EPSG:3035");
  GeodeticDatum targetDatum = ((GeographicCRS) targetCRS).getDatum();
  GeodeticDatum sourceDatum =  ((ProjectedCRS) sourceCRS).getDatum();
  final BursaWolfParameters[] params = ((DefaultGeodeticDatum) sourceDatum).getBursaWolfParameters();
  assertEquals("This test requires that an explicit BursaWolf parameter exists.", 1, params.length);
  assertEquals("targetDatum", targetDatum, params[0].getTargetDatum());
  assertTrue("This test requires that the BursaWolf parameter is set to identity.", params[0].isIdentity());
  CoordinateReferenceSystem vertCRS = CRS.fromWKT(
      "VERT_CS[\"Sigma Level\",VERT_DATUM[\"Sigma Level\",2000],UNIT[\"level\",1.0],AXIS[\"Sigma Level\",DOWN]]");
  sourceCRS = new DefaultCompoundCRS(singletonMap(NAME_KEY, "ETRS89 + Sigma level"), sourceCRS, vertCRS);
  final MathTransform tr = CRS.findOperation(sourceCRS, targetCRS, null).getMathTransform();
  assertSame(tr, CRS.findOperation(sourceCRS, targetCRS, null).getMathTransform());
  assertSame(tr, CRS.findOperation(sourceCRS, targetCRS, null).getMathTransform());
  assertEquals(3, tr.getSourceDimensions());
  assertEquals(2, tr.getTargetDimensions());
}

  throws FactoryException
final BursaWolfParameters parameters = new BursaWolfParameters(null, null);
final Parameters pv = Parameters.castOrWrap(values);
boolean reverseRotation = false;
  parameters.reverseRotation();
return MathTransforms.linear(parameters.getPositionVectorTransformation(null));

final DoubleDouble period = period(time);
if (period == null && isTranslation()) {
  final Matrix4 matrix = new Matrix4();
  matrix.m03 = tX;
final DoubleDouble S = param(6, period);
S.divide(PPM, 0);
S.add(1, 0);                                                // S = 1 + dS / PPM;
final DoubleDouble  X = param(3, period); X.multiply(RS);
final DoubleDouble  Y = param(4, period); Y.multiply(RS);
final DoubleDouble  Z = param(5, period); Z.multiply(RS);
final DoubleDouble mX = new DoubleDouble(X); mX.negate();
final DoubleDouble mY = new DoubleDouble(Y); mY.negate();
final Integer       O = 0;                                  // Fetch Integer instance only once.
return Matrices.create(4, 4, new Number[] {
     S,  mZ,   Y,  param(0, period),
     Z,   S,  mX,  param(1, period),
    mY,   X,   S,  param(2, period),
     O,   O,   O,  1});

/**
 * Invokes {@link BursaWolfParameters#getPositionVectorTransformation(Date)}
 * and compares with our own matrix calculated using double arithmetic.
 */
private static MatrixSIS getPositionVectorTransformation(final BursaWolfParameters p) {
  final double   S = 1 + p.dS / BursaWolfParameters.PPM;
  final double  RS = TO_RADIANS * S;
  final Matrix4 expected = new Matrix4(
        S,  -p.rZ*RS,  +p.rY*RS,  p.tX,
    +p.rZ*RS,         S,  -p.rX*RS,  p.tY,
    -p.rY*RS,  +p.rX*RS,         S,  p.tZ,
        0,         0,         0,  1);
  final MatrixSIS matrix = MatrixSIS.castOrCopy(p.getPositionVectorTransformation(null));
  assertMatrixEquals("getPositionVectorTransformation", expected, matrix, p.isTranslation() ? 0 : 1E-14);
  return matrix;
}

/**
 * Returns a hash value for this object.
 *
 * @return the hash code value. This value does not need to be the same in past or future versions of this class.
 */
@Override
public int hashCode() {
  return Arrays.hashCode(getValues()) ^ (int) serialVersionUID;
}

  continue;
final BursaWolfParameters bwp = new BursaWolfParameters(datum, info.getDomainOfValidity(owner));
try (ResultSet result = executeQuery("BursaWolfParameters",
  "SELECT PARAMETER_CODE," +
  bwp.reverseRotation();

/**
 * {@inheritDoc}
 *
 * @return {@code true} if the given object is equal to this {@code TimeDependentBWP}.
 */
@Override
public boolean equals(final Object object) {
  return super.equals(object) && timeReference == ((TimeDependentBWP) object).timeReference;
}

/**
 * Invokes {@link BursaWolfParameters#getPositionVectorTransformation(Date)} for a date calculated from
 * the temporal elements on the given extent.  This method chooses an instant located midway between the
 * start and end time.
 */
private static Matrix createTransformation(final BursaWolfParameters bursaWolf, final Extent areaOfInterest) {
  /*
   * Implementation note: we know that we do not need to compute an instant if the parameters is
   * not a subclass of BursaWolfParameters. This optimisation covers the vast majority of cases.
   */
  return bursaWolf.getPositionVectorTransformation(bursaWolf.getClass() != BursaWolfParameters.class ?
      Extents.getDate(areaOfInterest, 0.5) : null);       // 0.5 is for choosing midway instant.
}

/**
 * Sets the parameters to the given values. The given array can have any length. The first array elements will be
 * assigned to the {@link #tX tX}, {@link #tY tY}, {@link #tZ tZ}, {@link #rX rX}, {@link #rY rY}, {@link #rZ rZ},
 * {@link #dS dS}, {@link #dtX}, {@link #dtY}, {@link #dtZ}, {@link #drX}, {@link #drY}, {@link #drZ} and
 * {@link #ddS} fields in that order.
 *
 * @param  elements  the new parameter values, as an array of any length.
 *
 * @since 0.6
 */
@Override
@SuppressWarnings("fallthrough")
public void setValues(final double... elements) {
  if (elements.length >= 8) {
    switch (elements.length) {
      default:  ddS = elements[13];  // Fallthrough everywhere.
      case 13:  drZ = elements[12];
      case 12:  drY = elements[11];
      case 11:  drX = elements[10];
      case 10:  dtZ = elements[ 9];
      case  9:  dtY = elements[ 8];
      case  8:  dtX = elements[ 7];
    }
  }
  super.setValues(elements);
}