src/test/java/org/apache/commons/math3/ode/nonstiff/MidpointFieldStepInterpolatorTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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
 *
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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package org.apache.commons.math3.ode.nonstiff;


import org.apache.commons.math3.Field;
import org.apache.commons.math3.RealFieldElement;
import org.apache.commons.math3.ode.FieldEquationsMapper;
import org.apache.commons.math3.ode.FieldODEStateAndDerivative;
import org.apache.commons.math3.util.Decimal64Field;
import org.junit.Test;

public class MidpointFieldStepInterpolatorTest extends RungeKuttaFieldStepInterpolatorAbstractTest {

    protected <T extends RealFieldElement<T>> RungeKuttaFieldStepInterpolator<T>
    createInterpolator(Field<T> field, boolean forward, T[][] yDotK,
                       FieldODEStateAndDerivative<T> globalPreviousState,
                       FieldODEStateAndDerivative<T> globalCurrentState,
                       FieldODEStateAndDerivative<T> softPreviousState,
                       FieldODEStateAndDerivative<T> softCurrentState,
                       FieldEquationsMapper<T> mapper) {
        return new MidpointFieldStepInterpolator<T>(field, forward, yDotK,
                                                    globalPreviousState, globalCurrentState,
                                                    softPreviousState, softCurrentState,
                                                    mapper);
    }

    protected <T extends RealFieldElement<T>> FieldButcherArrayProvider<T>
    createButcherArrayProvider(final Field<T> field) {
        return new MidpointFieldIntegrator<T>(field, field.getOne());
    }

    @Test
    public void interpolationAtBounds() {
        doInterpolationAtBounds(Decimal64Field.getInstance(), 1.0e-15);
    }

    @Test
    public void interpolationInside() {
        doInterpolationInside(Decimal64Field.getInstance(), 3.3e-4, 1.1e-5);
    }

    @Test
    public void nonFieldInterpolatorConsistency() {
        doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 1.4e-17, 1.0e-50, 1.0e-50, 7.0e-18);
    }

}