/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2005-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotools.referencing.operation.projection;
import java.util.Collection;
import java.awt.geom.Point2D;
import org.opengis.parameter.GeneralParameterDescriptor;
import org.opengis.parameter.ParameterValueGroup;
import org.opengis.parameter.ParameterDescriptor;
import org.opengis.parameter.ParameterDescriptorGroup;
import org.opengis.parameter.ParameterNotFoundException;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.ReferenceIdentifier;
import org.geotools.math.Complex;
import org.geotools.referencing.NamedIdentifier;
import org.geotools.metadata.iso.citation.Citations;
import static java.lang.Math.*;
/**
* The NZMG (New Zealand Map Grid) projection.
* <p>
* This is an implementation of algorithm published by
* <a href="http://www.govt.nz/record?recordid=28">Land Information New Zealand</a>.
* The algorithm is documented <a href="http://www.linz.govt.nz/rcs/linz/6137/">here</a>.
* <p>
* <b>Implementation note</b><br>
* This class make extensive use of {@link Complex} type which may be costly unless the compiler
* can inline on the stack. We assume that Jave 6 and above can do this optimization.
*
* @since 2.2
*
* @source $URL$
* @version $Id$
* @author Justin Deoliveira
* @author Martin Desruisseaux
*/
public class NewZealandMapGrid extends MapProjection {
/**
* For compatibility with different versions during deserialization.
*/
private static final long serialVersionUID = 8394817836243729133L;
/**
* Coefficients for forward and inverse projection.
*/
private static final Complex[] A = {
new Complex( 0.7557853228, 0.0 ),
new Complex( 0.249204646, 0.003371507 ),
new Complex( -0.001541739, 0.041058560 ),
new Complex( -0.10162907, 0.01727609 ),
new Complex( -0.26623489, -0.36249218 ),
new Complex( -0.6870983, -1.1651967 )
};
/**
* Coefficients for inverse projection.
*/
private static final Complex[] B = {
new Complex( 1.3231270439, 0.0 ),
new Complex( -0.577245789, -0.007809598 ),
new Complex( 0.508307513, -0.112208952 ),
new Complex( -0.15094762, 0.18200602 ),
new Complex( 1.01418179, 1.64497696 ),
new Complex( 1.9660549, 2.5127645 )
};
/**
* Coefficients for inverse projection.
*/
private static final double[] TPHI = new double[] {
1.5627014243, 0.5185406398, -0.03333098, -0.1052906, -0.0368594, 0.007317,
0.01220, 0.00394, -0.0013
};
/**
* Coefficients for forward projection.
*/
private static final double[] TPSI = new double[] {
0.6399175073, -0.1358797613, 0.063294409, -0.02526853, 0.0117879,
-0.0055161, 0.0026906, -0.001333, 0.00067, -0.00034
};
/**
* Constructs a new map projection with default parameter values.
*/
protected NewZealandMapGrid() {
this(Provider.PARAMETERS.createValue());
}
/**
* Constructs a new map projection from the supplied parameters.
*
* @param parameters The parameter values in standard units.
* @throws ParameterNotFoundException if a mandatory parameter is missing.
*/
protected NewZealandMapGrid(final ParameterValueGroup parameters)
throws ParameterNotFoundException
{
super(parameters);
}
/**
* {@inheritDoc}
*/
public ParameterDescriptorGroup getParameterDescriptors() {
return Provider.PARAMETERS;
}
/**
* Must be overridden because {@link Provider} uses instances of
* {@link ModifiedParameterDescriptor}. This hack was needed because the New Zeland map
* projection uses particular default values for parameters like "False Easting", etc.
*/
@Override
final boolean isExpectedParameter(final Collection<GeneralParameterDescriptor> expected,
final ParameterDescriptor param)
{
return ModifiedParameterDescriptor.contains(expected, param);
}
/**
* Transforms the specified (<var>λ</var>,<var>φ</var>) coordinates
* (units in radians) and stores the result in {@code ptDst} (linear distance
* on a unit sphere).
*/
protected Point2D transformNormalized(final double x, final double y,
final Point2D ptDst)
throws ProjectionException
{
final double dphi = (y - latitudeOfOrigin) * (180/PI * 3600E-5);
double dphi_pow_i = dphi;
double dpsi = 0;
for (int i=0; i<TPSI.length; i++) {
dpsi += (TPSI[i] * dphi_pow_i);
dphi_pow_i *= dphi;
}
// See implementation note in class javadoc.
final Complex theta = new Complex(dpsi, x);
final Complex power = new Complex(theta);
final Complex z = new Complex();
z.multiply(A[0], power);
for (int i=1; i<A.length; i++) {
power.multiply(power, theta);
z.addMultiply(z, A[i], power);
}
if (ptDst != null) {
ptDst.setLocation(z.imag, z.real);
return ptDst;
}
return new Point2D.Double(z.imag, z.real);
}
/**
* Transforms the specified (<var>x</var>,<var>y</var>) coordinates
* and stores the result in {@code ptDst}.
*/
protected Point2D inverseTransformNormalized(final double x, final double y,
final Point2D ptDst)
throws ProjectionException
{
// See implementation note in class javadoc.
final Complex z = new Complex(y, x);
final Complex power = new Complex(z);
final Complex theta = new Complex();
theta.multiply(B[0], z);
for (int j=1; j<B.length; j++) {
power.multiply(power, z);
theta.addMultiply(theta, B[j], power);
}
// Increasing the number of iterations through this loop decreases
// the error in the calculation, but 3 iterations gives 10-3 accuracy.
final Complex num = new Complex();
final Complex denom = new Complex();
final Complex t = new Complex();
for (int j=0; j<3; j++) {
power.power(theta, 2);
num.addMultiply(z, A[1], power);
for (int k=2; k<A.length; k++) {
power.multiply(power, theta);
t.multiply(A[k], power);
t.multiply(t, k);
num.add(num, t);
}
power.real = 1;
power.imag = 0;
denom.copy(A[0]);
for (int k=1; k<A.length; k++) {
power.multiply(power, theta);
t.multiply(A[k], power);
t.multiply(t, k+1);
denom.add(denom, t);
}
theta.divide(num, denom);
}
final double dpsi = theta.real;
double dpsi_pow_i = dpsi;
double dphi = TPHI[0] * dpsi;
for (int i=1; i<TPHI.length; i++) {
dpsi_pow_i *= dpsi;
dphi += (TPHI[i] * dpsi_pow_i);
}
dphi = dphi / (180/PI * 3600E-5) + latitudeOfOrigin;
if (ptDst != null) {
ptDst.setLocation(theta.imag, dphi);
return ptDst;
}
return new Point2D.Double(theta.imag, dphi);
}
//////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////
//////// ////////
//////// PROVIDERS ////////
//////// ////////
//////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////
/**
* The {@linkplain org.geotools.referencing.operation.MathTransformProvider math transform
* provider} for {@linkplain NewZealandMapGrid New Zealand Map Grid} (EPSG code 27200).
*
* @since 2.2
* @version $Id$
* @author Justin Deoliveira
*
* @see org.geotools.referencing.operation.DefaultMathTransformFactory
*/
public static class Provider extends AbstractProvider {
/**
* For compatibility with different versions during deserialization.
*/
private static final long serialVersionUID = -7716733400419275656L;
/**
* The parameters group.
*/
static final ParameterDescriptorGroup PARAMETERS = createDescriptorGroup(
new ReferenceIdentifier[] {
new NamedIdentifier(Citations.OGC, "New_Zealand_Map_Grid"),
new NamedIdentifier(Citations.EPSG, "New Zealand Map Grid"),
new NamedIdentifier(Citations.EPSG, "27200")
},
new ParameterDescriptor[] {
new ModifiedParameterDescriptor(SEMI_MAJOR, 6378388.0),
new ModifiedParameterDescriptor(SEMI_MINOR, 6378388.0*(1-1/297.0)),
new ModifiedParameterDescriptor(LATITUDE_OF_ORIGIN, -41.0),
new ModifiedParameterDescriptor(CENTRAL_MERIDIAN, 173.0),
new ModifiedParameterDescriptor(FALSE_EASTING, 2510000.0),
new ModifiedParameterDescriptor(FALSE_NORTHING, 6023150.0)
});
/**
* Constructs a new provider.
*/
public Provider() {
super(PARAMETERS);
}
/**
* Creates a transform from the specified group of parameter values. This method doesn't
* check for the spherical case, since the New Zealand Map Grid projection is used with
* the International 1924 ellipsoid.
*
* @param parameters The group of parameter values.
* @return The created math transform.
* @throws ParameterNotFoundException if a required parameter was not found.
*/
public MathTransform createMathTransform(final ParameterValueGroup parameters)
throws ParameterNotFoundException
{
return new NewZealandMapGrid(parameters);
}
}
}