Example usage for org.apache.commons.math.complex Complex sqrt

Introduction

In this page you can find the example usage for org.apache.commons.math.complex Complex sqrt.

Prototype

public Complex sqrt() 

Source Link

Document

Compute the <a href="http://mathworld.wolfram.com/SquareRoot.html" TARGET="_top"> square root</a> of this complex number.

Usage

From source file:geogebra.common.kernel.geos.GeoVec2D.java

/**
 * c = sqrt(a) Michael Borcherds 2010-02-07
 * /*from w  w  w .  j a v  a  2s .c o  m*/
 * @param a
 *            a
 * @param c
 *            c
 */
final public static void complexSqrt(GeoVec2D a, GeoVec2D c) {
    Complex out = new Complex(a.x, a.y);
    out = out.sqrt();
    c.x = out.getReal();
    c.y = out.getImaginary();
    c.setMode(Kernel.COORD_COMPLEX);
}

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From source file:org.eclipse.ice.reflectivity.ReflectivityCalculator.java

/**
 * This operation returns the value of the squared modulus of the specular
 * reflectivity for a single wave vector Q.
 *
 * @param waveVectorQ/*from   www.  ja va 2  s.com*/
 *            the value of the wave vector
 * @param wavelength
 *            the wavelength of the incident neutrons
 * @param tiles
 *            the list of Tiles that contains the physical parameters needed
 *            for the calculation, including the scattering densities,
 *            absorption parameters and thicknesses.
 * @return the squared modulus of the specular reflectivity
 */
public double getModSqrdSpecRef(double waveVectorQ, double wavelength, Tile[] tiles) {

    double modSqrdSpecRef = 0.0;

    if (wavelength > 0.0) {
        // Variables only needed if we are going to do the work, i.e. -
        // wavelength > 0.0.
        Tile tile;
        Complex aNm1Sq, fNm1N, rNm1N = new Complex(0.0, 0.0), one = new Complex(1.0, 0.0),
                qN = new Complex(0.0, 0.0), rNNp1 = new Complex(0.0, 0.0);
        // Get the bottom tile
        int nLayers = tiles.length;
        tile = tiles[nLayers - 1];
        // Starting point--no reflected beam in bottom-most (bulk) layer
        double qCSq = 16.0 * Math.PI * tile.scatteringLength;
        double muLAbs = tile.trueAbsLength;
        double mulInc = tile.incAbsLength;
        double thickness = tile.thickness;
        // Setup other values for the problem
        double betaNm1 = 4.0 * Math.PI * (muLAbs + mulInc / wavelength);
        Complex qNm1 = new Complex(waveVectorQ * waveVectorQ - qCSq, -2.0 * betaNm1);
        qNm1 = qNm1.sqrt();
        // Loop through to calculate recursion formula described in Parratt.
        // Start at the bottom and work up.
        for (int i = nLayers - 1; i > 0; i--) {
            // Get the tile above tile[i] (started at the bottom
            tile = tiles[i - 1];
            // Calculate the normal component of Q for layer and layer-1
            qN = qNm1;
            qCSq = 16.0 * Math.PI * tile.scatteringLength;
            muLAbs = tile.trueAbsLength;
            mulInc = tile.incAbsLength;
            thickness = tile.thickness;
            betaNm1 = 4.0 * Math.PI * (muLAbs + mulInc / wavelength);
            qNm1 = new Complex(waveVectorQ * waveVectorQ - qCSq, -2.0 * betaNm1);
            qNm1 = qNm1.sqrt();
            // Calculate phase factor, e^(-0.5*d*qNm1)
            aNm1Sq = (new Complex(qNm1.getImaginary(), qNm1.getReal()).multiply(-0.5 * thickness)).exp();
            // CDiv(qNm1-qN,qNm1+qN)
            fNm1N = qNm1.subtract(qN).divide(qNm1.add(qN));
            // Calculate the reflectivity amplitude.
            // CMult(aNm1Sq, CMult(aNm1Sq, CDiv(CAdd(rNNp1, fNm1N),
            // CAdd(CMult(rNNp1, fNm1N), CReal(1)))))
            Complex y = rNNp1.multiply(fNm1N).add(one);
            Complex z = rNNp1.add(fNm1N);
            rNm1N = aNm1Sq.multiply(aNm1Sq).multiply(z.divide((y)));
            // Carry over to the next iteration
            rNNp1 = rNm1N;
        }
        modSqrdSpecRef = rNm1N.getReal() * rNm1N.getReal() + rNm1N.getImaginary() * rNm1N.getImaginary();
    }

    return modSqrdSpecRef;
}

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