List of usage examples for org.apache.commons.math3.analysis.differentiation DerivativeStructure sqrt
public DerivativeStructure sqrt()
From source file:org.orekit.bodies.OneAxisEllipsoid.java
/** Transform a Cartesian point to a surface-relative point. * @param point Cartesian point// w w w.j a v a 2s . co m * @param frame frame in which Cartesian point is expressed * @param date date of the computation (used for frames conversions) * @return point at the same location but as a surface-relative point, * using time as the single derivation parameter * @exception OrekitException if point cannot be converted to body frame */ public FieldGeodeticPoint<DerivativeStructure> transform(final PVCoordinates point, final Frame frame, final AbsoluteDate date) throws OrekitException { // transform point to body frame final Transform toBody = frame.getTransformTo(bodyFrame, date); final PVCoordinates pointInBodyFrame = toBody.transformPVCoordinates(point); final FieldVector3D<DerivativeStructure> p = pointInBodyFrame.toDerivativeStructureVector(2); final DerivativeStructure pr2 = p.getX().multiply(p.getX()).add(p.getY().multiply(p.getY())); final DerivativeStructure pr = pr2.sqrt(); final DerivativeStructure pz = p.getZ(); // project point on the ellipsoid surface final TimeStampedPVCoordinates groundPoint = projectToGround( new TimeStampedPVCoordinates(date, pointInBodyFrame), bodyFrame); final FieldVector3D<DerivativeStructure> gp = groundPoint.toDerivativeStructureVector(2); final DerivativeStructure gpr2 = gp.getX().multiply(gp.getX()).add(gp.getY().multiply(gp.getY())); final DerivativeStructure gpr = gpr2.sqrt(); final DerivativeStructure gpz = gp.getZ(); // relative position of test point with respect to its ellipse sub-point final DerivativeStructure dr = pr.subtract(gpr); final DerivativeStructure dz = pz.subtract(gpz); final double insideIfNegative = g2 * (pr2.getReal() - ae2) + pz.getReal() * pz.getReal(); return new FieldGeodeticPoint<DerivativeStructure>(DerivativeStructure.atan2(gpz, gpr.multiply(g2)), DerivativeStructure.atan2(p.getY(), p.getX()), DerivativeStructure.hypot(dr, dz).copySign(insideIfNegative)); }
From source file:org.orekit.forces.BoxAndSolarArraySpacecraft.java
/** Get solar array normal in spacecraft frame. * @param date current date//from w w w. j av a 2 s.c o m * @param frame inertial reference frame for state (both orbit and attitude) * @param position position of spacecraft in reference frame * @param rotation orientation (attitude) of the spacecraft with respect to reference frame * @return solar array normal in spacecraft frame * @exception OrekitException if sun direction cannot be computed in best lightning * configuration */ public synchronized FieldVector3D<DerivativeStructure> getNormal(final AbsoluteDate date, final Frame frame, final FieldVector3D<DerivativeStructure> position, final FieldRotation<DerivativeStructure> rotation) throws OrekitException { final DerivativeStructure one = position.getX().getField().getOne(); if (referenceDate != null) { // use a simple rotation at fixed rate final DerivativeStructure alpha = one.multiply(rotationRate * date.durationFrom(referenceDate)); return new FieldVector3D<DerivativeStructure>(alpha.cos(), saX, alpha.sin(), saY); } // compute orientation for best lightning final FieldVector3D<DerivativeStructure> sunInert = position .subtract(sun.getPVCoordinates(date, frame).getPosition()).negate().normalize(); final FieldVector3D<DerivativeStructure> sunSpacecraft = rotation.applyTo(sunInert); final DerivativeStructure d = FieldVector3D.dotProduct(sunSpacecraft, saZ); final DerivativeStructure f = d.multiply(d).subtract(1).negate(); if (f.getValue() < Precision.EPSILON) { // extremely rare case: the sun is along solar array rotation axis // (there will not be much output power ...) // we set up an arbitrary normal return new FieldVector3D<DerivativeStructure>(one, saZ.orthogonal()); } final DerivativeStructure s = f.sqrt().reciprocal(); return new FieldVector3D<DerivativeStructure>(s, sunSpacecraft) .subtract(new FieldVector3D<DerivativeStructure>(s.multiply(d), saZ)); }
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); }
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//from w ww .j a v a 2s . co m 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)); }
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); }
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); }