FieldFixedNumberInterpolationGrid.java
/* Copyright 2002-2022 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,
* 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.propagation.semianalytical.dsst.utilities;
import org.hipparchus.Field;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.util.MathArrays;
/** Interpolation grid where a fixed number of points are
* evenly spaced between the start and the end of the integration step.
* <p>
* The grid is adapted to the step considered,
* meaning that for short steps, the grid will be dense,
* while for long steps the points will be far away one from each other
* </p>
*/
public class FieldFixedNumberInterpolationGrid<T extends CalculusFieldElement<T>> implements FieldInterpolationGrid<T> {
/** Number of points in the grid per step. */
private final int pointsPerStep;
/** Field used by default. */
private final Field<T> field;
/** Constructor.
* @param field field used by default
* @param pointsPerStep number of points in the grid per step
*/
public FieldFixedNumberInterpolationGrid(final Field<T> field, final int pointsPerStep) {
this.field = field;
this.pointsPerStep = pointsPerStep;
}
/** {@inheritDoc} */
@Override
public T[] getGridPoints(final T stepStart, final T stepEnd) {
final T[] grid = MathArrays.buildArray(field, pointsPerStep);
final T stepSize = (stepEnd.subtract(stepStart)).divide(pointsPerStep - 1);
for (int i = 0; i < pointsPerStep; i++) {
grid[i] = stepSize.multiply(i).add(stepStart);
}
return grid;
}
}