/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2011, Open Source Geospatial Foundation (OSGeo)
* (C) 2005 Open Geospatial Consortium Inc.
*
* All Rights Reserved. http://www.opengis.org/legal/
*/
package org.opengis.coverage;
import java.util.List;
import java.util.ArrayList;
import org.opengis.util.CodeList;
import org.opengis.annotation.UML;
import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;
/**
* A list of codes that identify interpolation methods that may be used for evaluating
* {@linkplain ContinuousCoverage continuous coverages}. Evaluation of a continuous coverage
* involves interpolation between known feature attribute values associated with geometric
* objects in the domain of the {@linkplain DiscreteCoverage discrete coverage} that is provided
* as control for the continuous coverage. This code list includes 9 interpolation methods. Each
* is used in the context of specified geometric configurations (table below). Since
* {@code InterpolationMethod} is a {@code CodeList}, it may be extended in an application
* schema that specifies additional interpolation methods.
* <p>
* <table border="1">
* <tr><th>Method</th> <th>Coverage Type</th> <th>Value object dimension</th></tr>
* <tr><td>Nearest Neighbour</td><td>Any</td> <td>Any</td></tr>
* <tr><td>Linear</td> <td>Segmented Curve</td> <td>1</td></tr>
* <tr><td>Quadratic</td> <td>Segmented Curve</td> <td>1</td></tr>
* <tr><td>Cubic</td> <td>Segmented Curve</td> <td>1</td></tr>
* <tr><td>Bilinear</td> <td>Quadrilateral Grid</td> <td>2</td></tr>
* <tr><td>Biquadratic</td> <td>Quadrilateral Grid</td> <td>2</td></tr>
* <tr><td>Bicubic</td> <td>Quadrilateral Grid</td> <td>2</td></tr>
* <tr><td>Lost Area</td> <td>Thiessen Polygon, Hexagonal Grid</td><td>2</td></tr>
* <tr><td>Barycentric</td> <td>TIN</td> <td>2</td></tr>
* </table>
*
*
* @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/opengis/src/main/java/org/opengis/coverage/InterpolationMethod.java $
* @version ISO 19123:2004
* @author Martin Desruisseaux (IRD)
* @since GeoAPI 2.1
*/
@UML(identifier="CV_InterpolationMethod", specification=ISO_19123)
public class InterpolationMethod extends CodeList<InterpolationMethod> {
/**
* Serial number for compatibility with different versions.
*/
private static final long serialVersionUID = -4289541167757079847L;
/**
* List of all enumerations of this type.
* Must be declared before any enum declaration.
*/
private static final List<InterpolationMethod> VALUES = new ArrayList<InterpolationMethod>(9);
/**
* Generates a feature attribute value at a direct position by assigning it the feature attribute
* value associated with the nearest domain object in the domain of the coverage. Nearest neighbour
* interpolation extends a discrete coverage to a step function defined on the convex hull of the
* domain objects in the domain of the coverage. Nearest neighbour interpolation is the only interpolation
* method described in ISO 19123 that can be used to interpolate attributes that have nominal or
* ordinal values.
* <p>
* <B>NOTE:</B> In the case of a discrete point coverage, the "steps" of the step function are
* the Thiessen polygons generated by the set of points in the domain of the coverage.
*/
@UML(identifier="Nearest neighbour", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod NEAREST_NEIGHBOUR = new InterpolationMethod("NEAREST_NEIGHBOUR");
/**
* Interpolation based on the assumption that feature attribute values vary in proportion to
* distance along a value segment.
* <p>
* <blockquote>
* <var>v</var> = <var>a</var> + <var>b</var><var>x</var>
* </blockquote>
* <p>
* Linear interpolation may be used to interpolate feature attribute values along a line segment
* connecting any two point value pairs. It may also be used to interpolate feature attribute values
* at positions along a curve of any form, if the positions are described by values of an arc-length
* parameter.
* <p>
* Given two point value pairs (<var>p</var><sub>s</sub>, </var>v</var><sub>s</sub>) and
* (<var>p</var><sub>t</sub>, <var>v</var><sub>t</sub>), where <var>p</var><sub>s</sub> is
* the start point and <var>p</var><sub>t</sub> is the end point of a value segment,
* and <var>v</var><sub>s</sub> and <var>v</var><sub>t</sub> are the feature attribute
* values associated with those points, the feature attribute value <var>v</var><sub>i</sub>
* associated with the direct position <var>p</var><sub>i</sub> is:
* <p>
* <blockquote>
* <var>v</var><sub>i</sub> = <var>v</var><sub>s</sub> + (<var>v</var><sub>t</sub> - <var>v</var><sub>s</sub>)
* ((<var>p</var><sub>i</sub> - <var>p</var><sub>s</sub>)/(<var>p</var><sub>t</sub> - <var>p<var><sub>s</sub>))
* </blockquote>
*/
@UML(identifier="Linear interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod LINEAR = new InterpolationMethod("LINEAR");
/**
* Interpolation based on the assumption that feature attribute values vary as a quadratic
* function of distance along a value segment.
* <p>
* <blockquote>
* <var>v</var> = <var>a</var>
* + <var>b</var><var>x</var>
* + <var>c</var><var>x</var><sup>2</sup>
* </blockquote>
* <p>
* where <var>a</var> is the value of a feature attribute at the start of a value segment and
* <var>v</var> is the value of a feature attribute at distance <var>x</var> along the curve
* from the start. Three point value pairs are needed to provide control values for calculating
* the coefficients of the function.
*/
@UML(identifier="Quadratic interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod QUADRATIC = new InterpolationMethod("QUADRATIC");
/**
* Interpolation based on the assumption that feature attribute values vary as a cubic function
* of distance along a value segment.
* <p>
* <blockquote>
* <var>v</var> = <var>a</var>
* + <var>b</var><var>x</var>
* + <var>c</var><var>x</var><sup>2</sup>
* + <var>d</var><var>x</var><sup>3</sup>
* </blockquote>
* <p>
* where <var>a</var> is the value of a feature attribute at the start of a value segment and
* <var>v</var> is the value of a feature attribute at distance <var>x</var> along the curve
* from the start. Four point value pairs are needed to provide control values for calculating
* the coefficients of the function.
*/
@UML(identifier="Cubic interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod CUBIC = new InterpolationMethod("CUBIC");
/**
* Interpolation based on the assumption that feature attribute values vary as a bilinear function
* of position within the grid cell.
*/
@UML(identifier="Bilinear interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod BILINEAR = new InterpolationMethod("BILINEAR");
/**
* Interpolation based on the assumption that feature attribute values vary as a biquadratic function
* of position within the grid cell.
*/
@UML(identifier="Biquadratic interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod BIQUADRATIC = new InterpolationMethod("BIQUADRATIC");
/**
* Interpolation based on the assumption that feature attribute values vary as a bicubic function
* of position within the grid cell.
*/
@UML(identifier="Bicubic interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod BICUBIC = new InterpolationMethod("BICUBIC");
/**
* Lost area interpolation.
*/
@UML(identifier="Lost area interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod LOST_AREA = new InterpolationMethod("LOST_AREA");
/**
* Barycentric interpolation.
*/
@UML(identifier="Barycentric interpolation", obligation=CONDITIONAL, specification=ISO_19123)
public static final InterpolationMethod BARYCENTRIC = new InterpolationMethod("BARYCENTRIC");
/**
* Constructs an enum with the given name. The new enum is
* automatically added to the list returned by {@link #values}.
*
* @param name The enum name. This name must not be in use by an other enum of this type.
*/
private InterpolationMethod(final String name) {
super(name, VALUES);
}
/**
* Returns the list of {@code InterpolationMethod}s.
*
* @return The list of codes declared in the current JVM.
*/
public static InterpolationMethod[] values() {
synchronized (VALUES) {
return VALUES.toArray(new InterpolationMethod[VALUES.size()]);
}
}
/**
* Returns the list of enumerations of the same kind than this enum.
*/
public InterpolationMethod[] family() {
return values();
}
/**
* Returns the interpolation method that matches the given string, or returns a
* new one if none match it.
*
* @param code The name of the code to fetch or to create.
* @return A code matching the given name.
*/
public static InterpolationMethod valueOf(String code) {
return valueOf(InterpolationMethod.class, code);
}
}