package org.geotools.referencing.operation.projection;
import static org.geotools.referencing.operation.projection.MapProjection.AbstractProvider.*;
import static org.junit.Assert.*;
import org.geotools.parameter.ParameterGroup;
import org.geotools.referencing.ReferencingFactoryFinder;
import org.junit.Test;
import org.opengis.parameter.ParameterDescriptor;
import org.opengis.parameter.ParameterValue;
import org.opengis.parameter.ParameterValueGroup;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.operation.MathTransformFactory;
/**
*
*
* @source $URL$
*/
public class CassiniSoldnerTest {
/**
* Tests the example provided by the EPSG guidance.
* See "OGP Surveying and Positioning Guidance Note number 7, part 2 – April 2009", page 36
*/
@Test
public void testEpsgExample() throws Exception {
MathTransformFactory mtFactory = ReferencingFactoryFinder.getMathTransformFactory(null);
final ParameterValueGroup parameters = mtFactory.getDefaultParameters("Cassini-Soldner");
// build the transformation using the guidance provided values
final double feetToMeter = 0.3048; // ft -> mt
final double linkToMeter = 0.66 * feetToMeter; // Clark's links -> mt
parameter(SEMI_MAJOR, parameters).setValue(20926348 * feetToMeter);
parameter(SEMI_MINOR, parameters).setValue(20855233 * feetToMeter);
parameter(LATITUDE_OF_ORIGIN, parameters).setValue(dmsToDegree(10, 26, 30));
parameter(CENTRAL_MERIDIAN, parameters).setValue(-dmsToDegree(61, 20, 0));
parameter(FALSE_EASTING, parameters).setValue(430000.00 * linkToMeter);
parameter(FALSE_NORTHING, parameters).setValue(325000.00 * linkToMeter);
MathTransform transform = mtFactory.createParameterizedTransform(parameters);
// results as provided by the EPSG guidance
final double[] point = new double[] { -62, 10 };
final double[] expected = new double[] { 66644.94 * linkToMeter, 82536.22 * linkToMeter };
// check forward transform
final double[] forward = new double[2];
transform.transform(point, 0, forward, 0, 1);
assertEquals(expected[0], forward[0], 1e-1);
assertEquals(expected[1], forward[1], 1e-1);
// check inverse transform
final double[] inverse = new double[2];
transform.inverse().transform(expected, 0, inverse, 0, 1);
assertEquals(point[0], inverse[0], 1e-4);
assertEquals(inverse[1], inverse[1], 1e-4);
}
/**
* Extracts the {@link ParameterValue} for a certain {@link ParameterDescriptor}
*/
ParameterValue parameter(ParameterDescriptor param, ParameterValueGroup group) {
return group.parameter(param.getName().getCode());
}
/**
* Converts a DMS value into degrees
*/
double dmsToDegree(double degrees, double minutes, double seconds) {
return degrees + (minutes + seconds / 60) / 60;
}
}