OrbitCovariance.java
/* Copyright 2002-2024 CS GROUP
* Licensed to CS GROUP (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,
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package org.orekit.files.ccsds.ndm.odm.ocm;
import java.util.List;
import org.hipparchus.linear.MatrixUtils;
import org.hipparchus.linear.RealMatrix;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.TimeStamped;
import org.orekit.utils.units.Unit;
/** Covariance entry.
* @author Luc Maisonobe
* @since 11.0
*/
public class OrbitCovariance implements TimeStamped {
/** Type of the elements. */
private final OrbitElementsType type;
/** Entry date. */
private final AbsoluteDate date;
/** Covariance matrix. */
private final RealMatrix matrix;
/** Simple constructor.
* @param type type of the elements
* @param ordering ordering to use
* @param date entry date
* @param fields matrix elements
* @param first index of first field to consider
*/
public OrbitCovariance(final OrbitElementsType type, final Ordering ordering, final AbsoluteDate date,
final String[] fields, final int first) {
final List<Unit> units = type.getUnits();
this.type = type;
this.date = date;
this.matrix = MatrixUtils.createRealMatrix(units.size(), units.size());
final CovarianceIndexer indexer = new CovarianceIndexer(units.size());
for (int k = 0; first + k < fields.length; ++k) {
if (!indexer.isCrossCorrelation()) {
final int i = indexer.getRow();
final int j = indexer.getColumn();
final double raw = Double.parseDouble(fields[first + k]);
final double converted = units.get(i).toSI(units.get(j).toSI(raw));
matrix.setEntry(i, j, converted);
if (i != j) {
matrix.setEntry(j, i, converted);
}
}
ordering.update(indexer);
}
}
/** {@inheritDoc} */
@Override
public AbsoluteDate getDate() {
return date;
}
/** Get the covariance matrix.
* @return covariance matrix
*/
public RealMatrix getMatrix() {
return matrix;
}
/** Get the type of the elements.
* @return type of the elements
*/
public OrbitElementsType getType() {
return type;
}
}