Example usage for org.apache.commons.math3.geometry.euclidean.threed FieldVector3D getNormSq

Introduction

In this page you can find the example usage for org.apache.commons.math3.geometry.euclidean.threed FieldVector3D getNormSq.

Prototype

public T getNormSq() 

Source Link

Document

Get the square of the norm for the vector.

Usage

From source file:org.orekit.forces.BoxAndSolarArraySpacecraft.java

/** {@inheritDoc} */
public FieldVector3D<DerivativeStructure> radiationPressureAcceleration(final AbsoluteDate date,
        final Frame frame, final FieldVector3D<DerivativeStructure> position,
        final FieldRotation<DerivativeStructure> rotation, final DerivativeStructure mass,
        final FieldVector3D<DerivativeStructure> flux) throws OrekitException {

    if (flux.getNormSq().getValue() < Precision.SAFE_MIN) {
        // null illumination (we are probably in umbra)
        return new FieldVector3D<DerivativeStructure>(0.0, flux);
    }// ww  w .  j a  v a2  s  . c  o m

    // radiation flux in spacecraft frame
    final FieldVector3D<DerivativeStructure> fluxSat = rotation.applyTo(flux);

    // solar array contribution
    FieldVector3D<DerivativeStructure> normal = getNormal(date, frame, position, rotation);
    DerivativeStructure dot = FieldVector3D.dotProduct(normal, fluxSat);
    if (dot.getValue() > 0) {
        // the solar array is illuminated backward,
        // fix signs to compute contribution correctly
        dot = dot.negate();
        normal = normal.negate();
    }
    FieldVector3D<DerivativeStructure> force = facetRadiationAcceleration(normal, solarArrayArea, fluxSat, dot);

    // body facets contribution
    for (final Facet bodyFacet : facets) {
        normal = new FieldVector3D<DerivativeStructure>(mass.getField().getOne(), bodyFacet.getNormal());
        dot = FieldVector3D.dotProduct(normal, fluxSat);
        if (dot.getValue() < 0) {
            // the facet intercepts the incoming flux
            force = force.add(facetRadiationAcceleration(normal, bodyFacet.getArea(), fluxSat, dot));
        }
    }

    // convert to inertial frame
    return rotation.applyInverseTo(new FieldVector3D<DerivativeStructure>(mass.reciprocal(), force));

}

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From source file:org.orekit.forces.gravity.NewtonianAttraction.java

/** {@inheritDoc} */
public FieldVector3D<DerivativeStructure> accelerationDerivatives(final AbsoluteDate date, final Frame frame,
        final FieldVector3D<DerivativeStructure> position, final FieldVector3D<DerivativeStructure> velocity,
        final FieldRotation<DerivativeStructure> rotation, final DerivativeStructure mass)
        throws OrekitException {

    final DerivativeStructure r2 = position.getNormSq();
    return new FieldVector3D<DerivativeStructure>(r2.sqrt().multiply(r2).reciprocal().multiply(-mu), position);

}

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From source file:org.orekit.forces.gravity.Relativity.java

@Override
public FieldVector3D<DerivativeStructure> accelerationDerivatives(final AbsoluteDate date, final Frame frame,
        final FieldVector3D<DerivativeStructure> position, final FieldVector3D<DerivativeStructure> velocity,
        final FieldRotation<DerivativeStructure> rotation, final DerivativeStructure mass) {

    //radius/* w w w . j a  v  a2  s  .  c  om*/
    final DerivativeStructure r2 = position.getNormSq();
    final DerivativeStructure r = r2.sqrt();
    //speed squared
    final DerivativeStructure s2 = velocity.getNormSq();
    final double c2 = Constants.SPEED_OF_LIGHT * Constants.SPEED_OF_LIGHT;
    //eq. 3.146
    return new FieldVector3D<DerivativeStructure>(r.reciprocal().multiply(4 * this.gm).subtract(s2), position,
            position.dotProduct(velocity).multiply(4), velocity)
                    .scalarMultiply(r2.multiply(r).multiply(c2).reciprocal().multiply(this.gm));

}

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From source file:org.orekit.forces.gravity.ThirdBodyAttraction.java

/** {@inheritDoc} */
public FieldVector3D<DerivativeStructure> accelerationDerivatives(final AbsoluteDate date, final Frame frame,
        final FieldVector3D<DerivativeStructure> position, final FieldVector3D<DerivativeStructure> velocity,
        final FieldRotation<DerivativeStructure> rotation, final DerivativeStructure mass)
        throws OrekitException {

    // compute bodies separation vectors and squared norm
    final Vector3D centralToBody = body.getPVCoordinates(date, frame).getPosition();
    final double r2Central = centralToBody.getNormSq();
    final FieldVector3D<DerivativeStructure> satToBody = position.subtract(centralToBody).negate();
    final DerivativeStructure r2Sat = satToBody.getNormSq();

    // compute relative acceleration
    final FieldVector3D<DerivativeStructure> satAcc = new FieldVector3D<DerivativeStructure>(
            r2Sat.sqrt().multiply(r2Sat).reciprocal().multiply(gm), satToBody);
    final Vector3D centralAcc = new Vector3D(gm / (r2Central * FastMath.sqrt(r2Central)), centralToBody);
    return satAcc.subtract(centralAcc);

}

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From source file:org.orekit.forces.radiation.SolarRadiationPressure.java

/** {@inheritDoc} */
public FieldVector3D<DerivativeStructure> accelerationDerivatives(final AbsoluteDate date, final Frame frame,
        final FieldVector3D<DerivativeStructure> position, final FieldVector3D<DerivativeStructure> velocity,
        final FieldRotation<DerivativeStructure> rotation, final DerivativeStructure mass)
        throws OrekitException {

    final FieldVector3D<DerivativeStructure> sunSatVector = position
            .subtract(sun.getPVCoordinates(date, frame).getPosition());
    final DerivativeStructure r2 = sunSatVector.getNormSq();

    // compute flux
    final double ratio = getLightningRatio(position.toVector3D(), frame, date);
    final DerivativeStructure rawP = r2.reciprocal().multiply(kRef * ratio);
    final FieldVector3D<DerivativeStructure> flux = new FieldVector3D<DerivativeStructure>(
            rawP.divide(r2.sqrt()), sunSatVector);

    // compute acceleration with all its partial derivatives
    return spacecraft.radiationPressureAcceleration(date, frame, position, rotation, mass, flux);

}

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From source file:org.orekit.utils.FieldPVCoordinatesTest.java

@Test
public void testGetAngularVelocity() {
    //setup// w w  w . j  av a  2  s.  co m
    DerivativeStructure oneDS = new DerivativeStructure(1, 1, 1);
    DerivativeStructure zeroDS = new DerivativeStructure(1, 1, 0);
    FieldVector3D<DerivativeStructure> zero = new FieldVector3D<DerivativeStructure>(zeroDS, zeroDS, zeroDS);
    FieldVector3D<DerivativeStructure> i = new FieldVector3D<DerivativeStructure>(oneDS, zeroDS, zeroDS);
    FieldVector3D<DerivativeStructure> j = new FieldVector3D<DerivativeStructure>(zeroDS, oneDS, zeroDS);
    FieldVector3D<DerivativeStructure> k = new FieldVector3D<DerivativeStructure>(zeroDS, zeroDS, oneDS);
    FieldVector3D<DerivativeStructure> p = new FieldVector3D<DerivativeStructure>(oneDS,
            new DerivativeStructure(1, 1, -2), new DerivativeStructure(1, 1, 3));
    FieldVector3D<DerivativeStructure> v = new FieldVector3D<DerivativeStructure>(
            new DerivativeStructure(1, 1, -9), new DerivativeStructure(1, 1, 8),
            new DerivativeStructure(1, 1, -7));

    //action + verify
    Assert.assertEquals(new FieldPVCoordinates<DerivativeStructure>(p, v).getAngularVelocity(),
            p.crossProduct(v).scalarMultiply(p.getNormSq().reciprocal()));
    //check extra simple cases
    Assert.assertEquals(
            new FieldPVCoordinates<DerivativeStructure>(i, i.scalarMultiply(-1)).getAngularVelocity(), zero);
    Assert.assertEquals(
            new FieldPVCoordinates<DerivativeStructure>(i.scalarMultiply(2), j).getAngularVelocity(),
            k.scalarMultiply(0.5));
}

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