GridCell.java
/* Copyright 2002-2024 Thales Alenia Space
* Licensed to CS Communication & Systèmes (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.orekit.models.earth.troposphere.iturp834;
/** Holder for one cell of grid data surrounding one point.
* @author Luc Maisonobe
* @since 13.0
*/
class GridCell {
/** Latitude difference with respect to South cell edge. */
private final double deltaSouth;
/** Longitude difference with respect to West cell edge. */
private final double deltaWest;
/** Cell size in latitude. */
private final double sizeLat;
/** Cell size in longitude. */
private final double sizeLon;
/** North-West value. */
private final double nw;
/** South-West value. */
private final double sw;
/** South-East value. */
private final double se;
/** North-East value. */
private final double ne;
/**
* Build a grid cell from corner data.
*
* @param deltaSouth point latitude minus South cell edge latitude
* @param deltaWest point longitude minus West cell edge longitude
* @param sizeLat cell size in latitude
* @param sizeLon cell size in longitude
* @param nw North-West value
* @param sw South-West value
* @param se South-East value
* @param ne North-East value
*/
GridCell(final double deltaSouth, final double deltaWest, final double sizeLat, final double sizeLon,
final double nw, final double sw, final double se, final double ne) {
this.deltaSouth = deltaSouth;
this.deltaWest = deltaWest;
this.sizeLat = sizeLat;
this.sizeLon = sizeLon;
this.nw = nw;
this.sw = sw;
this.se = se;
this.ne = ne;
}
/** Build a grid cell by applying a function to two existing cells.
* <p>
* The cells are expected to be consistent (i.e. same locations,
* same sizes), but no verification is done here. It works in
* the context of ITR-R P.834 because the grids have similar
* samplings, it would not work fro general and inconsistent grids.
* </p>
* @param function function to apply to all cells corners
* @param cell1 first cell
* @param cell2 second cell
*/
GridCell(final BiFunction function,
final GridCell cell1, final GridCell cell2) {
this.deltaSouth = cell1.deltaSouth;
this.deltaWest = cell1.deltaWest;
this.sizeLat = cell1.sizeLat;
this.sizeLon = cell1.sizeLon;
this.nw = function.apply(cell1.nw, cell2.nw);
this.sw = function.apply(cell1.sw, cell2.sw);
this.se = function.apply(cell1.se, cell2.se);
this.ne = function.apply(cell1.ne, cell2.ne);
}
/** Build a grid cell by applying a function to three existing cells.
* <p>
* The cells are expected to be consistent (i.e. same locations,
* same sizes), but no verification is done here. It works in
* the context of ITR-R P.834 because the grids have similar
* samplings, it would not work fro general and inconsistent grids.
* </p>
* @param function function to apply to all cells corners
* @param cell1 first cell
* @param cell2 second cell
* @param cell3 third cell
*/
GridCell(final TriFunction function,
final GridCell cell1, final GridCell cell2, final GridCell cell3) {
this.deltaSouth = cell1.deltaSouth;
this.deltaWest = cell1.deltaWest;
this.sizeLat = cell1.sizeLat;
this.sizeLon = cell1.sizeLon;
this.nw = function.apply(cell1.nw, cell2.nw, cell3.nw);
this.sw = function.apply(cell1.sw, cell2.sw, cell3.sw);
this.se = function.apply(cell1.se, cell2.se, cell3.se);
this.ne = function.apply(cell1.ne, cell2.ne, cell3.ne);
}
/** Build a grid cell by applying a function to four existing cells.
* <p>
* The cells are expected to be consistent (i.e. same locations,
* same sizes), but no verification is done here. It works in
* the context of ITR-R P.834 because the grids have similar
* samplings, it would not work fro general and inconsistent grids.
* </p>
* @param function function to apply to all cells corners
* @param cell1 first cell
* @param cell2 second cell
* @param cell3 third cell
* @param cell4 fourth cell
*/
GridCell(final QuarticFunction function,
final GridCell cell1, final GridCell cell2,
final GridCell cell3, final GridCell cell4) {
this.deltaSouth = cell1.deltaSouth;
this.deltaWest = cell1.deltaWest;
this.sizeLat = cell1.sizeLat;
this.sizeLon = cell1.sizeLon;
this.nw = function.apply(cell1.nw, cell2.nw, cell3.nw, cell4.nw);
this.sw = function.apply(cell1.sw, cell2.sw, cell3.sw, cell4.sw);
this.se = function.apply(cell1.se, cell2.se, cell3.se, cell4.se);
this.ne = function.apply(cell1.ne, cell2.ne, cell3.ne, cell4.ne);
}
/** Build a grid cell by applying a function to five existing cells.
* <p>
* The cells are expected to be consistent (i.e. same locations,
* same sizes), but no verification is done here. It works in
* the context of ITR-R P.834 because the grids have similar
* samplings, it would not work fro general and inconsistent grids.
* </p>
* @param function function to apply to all cells corners
* @param cell1 first cell
* @param cell2 second cell
* @param cell3 third cell
* @param cell4 fourth cell
* @param cell5 fifth cell
*/
GridCell(final QuinticFunction function,
final GridCell cell1, final GridCell cell2, final GridCell cell3,
final GridCell cell4, final GridCell cell5) {
this.deltaSouth = cell1.deltaSouth;
this.deltaWest = cell1.deltaWest;
this.sizeLat = cell1.sizeLat;
this.sizeLon = cell1.sizeLon;
this.nw = function.apply(cell1.nw, cell2.nw, cell3.nw, cell4.nw, cell5.nw);
this.sw = function.apply(cell1.sw, cell2.sw, cell3.sw, cell4.sw, cell5.sw);
this.se = function.apply(cell1.se, cell2.se, cell3.se, cell4.se, cell5.se);
this.ne = function.apply(cell1.ne, cell2.ne, cell3.ne, cell4.ne, cell5.ne);
}
/** Evaluate cell value at point location using bi-linear interpolation.
* @return cell value at point location
*/
public double evaluate() {
final double deltaNorth = sizeLat - deltaSouth;
final double deltaEast = sizeLon - deltaWest;
return (deltaSouth * (deltaWest * ne + deltaEast * nw) +
deltaNorth * (deltaWest * se + deltaEast * sw)) /
(sizeLat * sizeLon);
}
/** Interface for function that can be applied to the corners of two cells. */
@FunctionalInterface
public interface BiFunction {
/** Apply function to similar corners coming from two cells.
* @param corner1 value at corner of first cell
* @param corner2 value at corner of second cell
* @return function evaluated at similar corners of two cells
*/
double apply(double corner1, double corner2);
}
/** Interface for function that can be applied to the corners of three cells. */
@FunctionalInterface
public interface TriFunction {
/** Apply function to similar corners coming from three cells.
* @param corner1 value at corner of first cell
* @param corner2 value at corner of second cell
* @param corner3 value at corner of third cell
* @return function evaluated at similar corners of three cells
*/
double apply(double corner1, double corner2, double corner3);
}
/** Interface for function that can be applied to the corners of four cells. */
@FunctionalInterface
public interface QuarticFunction {
/** Apply function to similar corners coming from four cells.
* @param corner1 value at corner of first cell
* @param corner2 value at corner of second cell
* @param corner3 value at corner of third cell
* @param corner4 value at corner of fourth cell
* @return function evaluated at similar corners of four cells
*/
double apply(double corner1, double corner2, double corner3, double corner4);
}
/** Interface for function that can be applied to the corners of five cells. */
@FunctionalInterface
public interface QuinticFunction {
/** Apply function to similar corners coming from five cells.
* @param corner1 value at corner of first cell
* @param corner2 value at corner of second cell
* @param corner3 value at corner of third cell
* @param corner4 value at corner of fourth cell
* @param corner5 value at corner of fifth cell
* @return function evaluated at similar corners of five cells
*/
double apply(double corner1, double corner2, double corner3, double corner4, double corner5);
}
}