Example usage for java.lang Math cos

Introduction

In this page you can find the example usage for java.lang Math cos.

Prototype

@HotSpotIntrinsicCandidate
public static double cos(double a) 

Source Link

Document

Returns the trigonometric cosine of an angle.

Usage

From source file:Main.java

static double distanceFromPointOnArc(double dA, double dB, double dAB) {
    // In spherical trinagle ABC
    // a is length of arc BC, that is dB
    // b is length of arc AC, that is dA
    // c is length of arc AB, that is dAB
    // We rename parameters so following formulas are more clear:
    double a = dB;
    double b = dA;
    double c = dAB;

    // First, we calculate angles alpha and beta in spherical triangle ABC
    // and based on them we decide how to calculate the distance:
    if (Math.sin(b) * Math.sin(c) == 0.0 || Math.sin(c) * Math.sin(a) == 0.0) {
        // It probably means that one of distance is n*pi, which gives around 20000km for n = 1,
        // unlikely for Denmark, so we should be fine.
        return -1.0;
    }//from  ww  w.  ja  v a 2s  .  com

    double alpha = Math.acos((Math.cos(a) - Math.cos(b) * Math.cos(c)) / (Math.sin(b) * Math.sin(c)));
    double beta = Math.acos((Math.cos(b) - Math.cos(c) * Math.cos(a)) / (Math.sin(c) * Math.sin(a)));

    // It is possible that both sinuses are too small so we can get nan when dividing with them
    if (Double.isNaN(alpha) || Double.isNaN(beta)) {
        return -1.0;
    }

    // If alpha or beta are zero or pi, it means that C is on the same circle as arc AB,
    // we just need to figure out if it is between AB:
    if (alpha == 0.0 || beta == 0.0) {
        return (dA + dB > dAB) ? Math.min(dA, dB) : 0.0;
    }

    // If alpha is obtuse and beta is acute angle, then
    // distance is equal to dA:
    if (alpha > Math.PI / 2 && beta < Math.PI / 2)
        return -1;

    // Analogously, if beta is obtuse and alpha is acute angle, then
    // distance is equal to dB:
    if (beta > Math.PI / 2 && alpha < Math.PI / 2)
        return -1;

    // Again, unlikely, since it would render at least pi/2*EARTH_RADIUS_IN_METERS, which is too much.
    if (Math.cos(a) == 0.0)
        return -1;

    double x = Math.atan(-1.0 / Math.tan(c) + (Math.cos(b) / (Math.cos(a) * Math.sin(c))));

    return x;
}

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From source file:Main.java

public static PointF[] getIntersectionPoints(PointF pMiddle, float radius, Double lineK) {
    PointF[] points = new PointF[2];

    float radian, xOffset = 0, yOffset = 0;
    if (lineK != null) {
        radian = (float) Math.atan(lineK);
        xOffset = (float) (Math.sin(radian) * radius);
        yOffset = (float) (Math.cos(radian) * radius);
    } else {// w  w  w . j av  a2s .co m
        xOffset = radius;
        yOffset = 0;
    }
    points[0] = new PointF(pMiddle.x + xOffset, pMiddle.y - yOffset);
    points[1] = new PointF(pMiddle.x - xOffset, pMiddle.y + yOffset);

    return points;
}

---

From source file:Main.java

public static double getDistance(double lat1, double lng1, double lat2, double lng2) {
    double radLat1 = rad(lat1);
    double radLat2 = rad(lat2);
    double a = radLat1 - radLat2;
    double b = rad(lng1) - rad(lng2);
    double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
            + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
    s = s * EARTH_RADIUS;/*from w  w  w  .j a va2 s  .  co  m*/
    s = Math.round(s * 10000d) / 10000d;
    s = s * 1000;
    return s;
}

---

From source file:Main.java

/***
 * Fetch the raw estimated time enroute given the input parameters
 * @param distance - how far to the target
 * @param speed - how fast we are moving
 * @param bearing - direction to target/*from   w w w.  j  a  va  2s . c om*/
 * @param heading - direction of movement
 * @return int value of HR * 100 + MIN for the ete, -1 if not applicable
 */
private static int fetchRawEte(double distance, double speed, double bearing, double heading) {
    // We can't assume that we are heading DIRECTLY for the destination, so 
    // we need to figure out the multiply factor by taking the COS of the difference
    // between the bearing and the heading.
    double angDif = angularDifference(heading, bearing);

    // If the difference is 90 or greater, then ETE means nothing as we are not
    // closing on the target
    if (angDif >= 90)
        return -1;

    // Calculate the actual relative speed closing on the target
    double xFactor = Math.cos(angDif * Math.PI / 180);
    double eteTotal = distance / (speed * xFactor);

    // Break that down into hours and minutes
    int eteHr = (int) eteTotal;
    int eteMin = (int) Math.round((eteTotal - (double) eteHr) * 60);

    // account for the minutes being 60
    if (eteMin >= 60) {
        eteHr++;
        eteMin -= 60;
    }

    // Return with our estimate
    return eteHr * 100 + eteMin;
}

---

From source file:Main.java

public static Bitmap rotateAndFrame(Bitmap bitmap) {
    final boolean positive = sRandom.nextFloat() >= 0.5f;
    final float angle = (ROTATION_ANGLE_MIN + sRandom.nextFloat() * ROTATION_ANGLE_EXTRA)
            * (positive ? 1.0f : -1.0f);
    final double radAngle = Math.toRadians(angle);

    final int bitmapWidth = bitmap.getWidth();
    final int bitmapHeight = bitmap.getHeight();

    final double cosAngle = Math.abs(Math.cos(radAngle));
    final double sinAngle = Math.abs(Math.sin(radAngle));

    final int strokedWidth = (int) (bitmapWidth + 2 * PHOTO_BORDER_WIDTH);
    final int strokedHeight = (int) (bitmapHeight + 2 * PHOTO_BORDER_WIDTH);

    final int width = (int) (strokedHeight * sinAngle + strokedWidth * cosAngle);
    final int height = (int) (strokedWidth * sinAngle + strokedHeight * cosAngle);

    final float x = (width - bitmapWidth) / 2.0f;
    final float y = (height - bitmapHeight) / 2.0f;

    final Bitmap decored = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    final Canvas canvas = new Canvas(decored);

    canvas.rotate(angle, width / 2.0f, height / 2.0f);
    canvas.drawBitmap(bitmap, x, y, sPaint);
    canvas.drawRect(x, y, x + bitmapWidth, y + bitmapHeight, sStrokePaint);

    return decored;
}

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From source file:Main.java

private static float transformAngle(Matrix m, float angleRadians) {
    // Construct and transform a vector oriented at the specified clockwise
    // angle from vertical.  Coordinate system: down is increasing Y, right is
    // increasing X.
    float[] v = new float[2];
    v[0] = (float) Math.sin(angleRadians);
    v[1] = (float) Math.cos(angleRadians);
    m.mapVectors(v);/*from   w w  w  .  j  a v a 2 s.c o m*/
    // Derive the transformed vector's clockwise angle from vertical.
    float result = (float) Math.atan2(v[0], -v[1]);
    if (result < -Math.PI / 2) {
        result += Math.PI;
    } else if (result > Math.PI / 2) {
        result -= Math.PI;
    }
    return result;
}

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From source file:Main.java

/**
 * Returns the correction factor for the solar irradiance due to the elliptical
 * orbit of the Sun.//  ww  w.jav  a 2s .c o  m
 *
 * @param day the day (of year) of interest.
 *
 * @return the correction factor.
 */
public static double getSolarIrradianceCorrectionFactor(int day) {
    final double d = 1.0 - 0.01673 * Math.cos(Math.toRadians(0.9856 * (day - 4)));

    return 1.0 / (d * d);
}

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From source file:Main.java

/**
 * Get the coordinates of a point on the line by cut length.
 *
 * @param A         Point A//from w w  w . j av  a  2 s .  c  o  m
 * @param B         Point B
 * @param cutLength cut length
 * @return the point.
 */
public static Point getPointByCutLength(Point A, Point B, int cutLength) {
    float radian = getRadian(A, B);
    return new Point(A.x + (int) (cutLength * Math.cos(radian)), A.y + (int) (cutLength * Math.sin(radian)));
}

---

From source file:Main.java

public static double getGeoDistance(double longitude1, double latitude1, double longitude2, double latitude2) {
    double EARTH_RADIUS = 6378137;
    double radLat1 = rad(latitude1);
    double radLat2 = rad(latitude2);
    double a = radLat1 - radLat2;
    double b = rad(longitude1) - rad(longitude2);
    double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
            + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
    s = s * EARTH_RADIUS;/*from   www .jav  a  2  s . com*/
    s = Math.round(s * 10000) / 10000;
    return s;
}

---

From source file:graticules2wld.Main.java

/**
 * @param args/* w w w. j  av a2 s  .c o  m*/
 * @throws Exception
 */
public static void main(String[] args) throws Exception {

    /* parse the command line arguments */
    // create the command line parser
    CommandLineParser parser = new PosixParser();

    // create the Options
    Options options = new Options();
    options.addOption("x", "originx", true, "x component of projected coordinates of upper left pixel");
    options.addOption("y", "originy", true, "y component of projected coordinates of upper left pixel");
    options.addOption("u", "tometers", true, "multiplication factor to get source units into meters");
    options.addOption("h", "help", false, "prints this usage page");
    options.addOption("d", "debug", false, "prints debugging information to stdout");

    double originNorthing = 0;
    double originEasting = 0;

    String inputFileName = null;
    String outputFileName = null;

    try {
        // parse the command line arguments
        CommandLine line = parser.parse(options, args);

        if (line.hasOption("help"))
            printUsage(0); // print usage then exit using a non error exit status

        if (line.hasOption("debug"))
            debug = true;

        // these arguments are required
        if (!line.hasOption("originy") || !line.hasOption("originx"))
            printUsage(1);

        originNorthing = Double.parseDouble(line.getOptionValue("originy"));
        originEasting = Double.parseDouble(line.getOptionValue("originx"));

        if (line.hasOption("tometers"))
            unitsToMeters = Double.parseDouble(line.getOptionValue("tometers"));

        // two args should be left. the input csv file name and the output wld file name.
        String[] iofiles = line.getArgs();
        if (iofiles.length < 2) {
            printUsage(1);
        }

        inputFileName = iofiles[0];
        outputFileName = iofiles[1];
    } catch (ParseException exp) {
        System.err.println("Unexpected exception:" + exp.getMessage());
        System.exit(1);
    }

    // try to open the input file for reading and the output file for writing
    File graticulesCsvFile;
    BufferedReader csvReader = null;

    File wldFile;
    BufferedWriter wldWriter = null;

    try {
        graticulesCsvFile = new File(inputFileName);
        csvReader = new BufferedReader(new FileReader(graticulesCsvFile));
    } catch (IOException exp) {
        System.err.println("Could not open input file for reading: " + inputFileName);
        System.exit(1);
    }

    try {
        wldFile = new File(outputFileName);
        wldWriter = new BufferedWriter(new FileWriter(wldFile));
    } catch (IOException exp) {
        System.err.println("Could not open output file for writing: " + outputFileName);
        System.exit(1);
    }

    // list of lon graticules and lat graticules
    ArrayList<Graticule> lonGrats = new ArrayList<Graticule>();
    ArrayList<Graticule> latGrats = new ArrayList<Graticule>();

    // read the source CSV and convert its information into the two ArrayList<Graticule> data structures
    readCSV(csvReader, lonGrats, latGrats);

    // we now need to start finding the world file paramaters
    DescriptiveStatistics stats = new DescriptiveStatistics();

    // find theta and phi
    for (Graticule g : latGrats) {
        stats.addValue(g.angle());
    }

    double theta = stats.getMean(); // we use the mean of the lat angles as theta
    if (debug)
        System.out.println("theta range = " + Math.toDegrees(stats.getMax() - stats.getMin()));
    stats.clear();

    for (Graticule g : lonGrats) {
        stats.addValue(g.angle());
    }

    double phi = stats.getMean(); // ... and the mean of the lon angles for phi
    if (debug)
        System.out.println("phi range = " + Math.toDegrees(stats.getMax() - stats.getMin()));
    stats.clear();

    // print these if in debug mode
    if (debug) {
        System.out.println("theta = " + Math.toDegrees(theta) + "deg");
        System.out.println("phi = " + Math.toDegrees(phi) + "deg");
    }

    // find x and y (distance beteen pixels in map units)
    Collections.sort(latGrats);
    Collections.sort(lonGrats);
    int prevMapValue = 0; //fixme: how to stop warning about not being initilised?
    Line2D prevGratPixelSys = new Line2D.Double();

    boolean first = true;
    for (Graticule g : latGrats) {
        if (!first) {
            int deltaMapValue = Math.abs(g.realValue() - prevMapValue);
            double deltaPixelValue = (g.l.ptLineDist(prevGratPixelSys.getP1())
                    + (g.l.ptLineDist(prevGratPixelSys.getP2()))) / 2;

            double delta = deltaMapValue / deltaPixelValue;
            stats.addValue(delta);
        } else {
            first = false;
            prevMapValue = g.realValue();
            prevGratPixelSys = (Line2D) g.l.clone();
        }
    }

    double y = stats.getMean();
    if (debug)
        System.out.println("y range = " + (stats.getMax() - stats.getMin()));
    stats.clear();

    first = true;
    for (Graticule g : lonGrats) {
        if (!first) {
            int deltaMapValue = g.realValue() - prevMapValue;
            double deltaPixelValue = (g.l.ptLineDist(prevGratPixelSys.getP1())
                    + (g.l.ptLineDist(prevGratPixelSys.getP2()))) / 2;

            double delta = deltaMapValue / deltaPixelValue;
            stats.addValue(delta);
        } else {
            first = false;
            prevMapValue = g.realValue();
            prevGratPixelSys = (Line2D) g.l.clone();
        }
    }

    double x = stats.getMean();
    if (debug)
        System.out.println("x range = " + (stats.getMax() - stats.getMin()));
    stats.clear();

    if (debug) {
        System.out.println("x = " + x);
        System.out.println("y = " + y);
    }

    SimpleRegression regression = new SimpleRegression();

    // C, F are translation terms: x, y map coordinates of the center of the upper-left pixel
    for (Graticule g : latGrats) {
        // find perp dist to pixel space 0,0
        Double perpPixelDist = g.l.ptLineDist(new Point2D.Double(0, 0));

        // find the map space distance from this graticule to the center of the 0,0 pixel
        Double perpMapDist = perpPixelDist * y; // perpMapDist / perpPixelDist = y

        regression.addData(perpMapDist, g.realValue());
    }

    double F = regression.getIntercept();
    regression.clear();

    for (Graticule g : lonGrats) {
        // find perp dist to pixel space 0,0
        Double perpPixelDist = g.l.ptLineDist(new Point2D.Double(0, 0));

        // find the map space distance from this graticule to the center of the 0,0 pixel
        Double perpMapDist = perpPixelDist * x; // perpMapDist / perpPixelDist = x

        regression.addData(perpMapDist, g.realValue());
    }

    double C = regression.getIntercept();
    regression.clear();

    if (debug) {
        System.out.println("Upper Left pixel has coordinates " + C + ", " + F);
    }

    // convert to meters
    C *= unitsToMeters;
    F *= unitsToMeters;

    // C,F store the projected (in map units) coordinates of the upper left pixel.
    // originNorthing,originEasting is the offset we need to apply to 0,0 to push the offsets into our global coordinate system 
    C = originEasting + C;
    F = originNorthing + F;

    // calculate the affine transformation matrix elements
    double D = -1 * x * unitsToMeters * Math.sin(theta);
    double A = x * unitsToMeters * Math.cos(theta);
    double B = y * unitsToMeters * Math.sin(phi); // if should be negative, it'll formed by negative sin
    double E = -1 * y * unitsToMeters * Math.cos(phi);

    /*
     * Line 1: A: pixel size in the x-direction in map units/pixel
     * Line 2: D: rotation about y-axis
     * Line 3: B: rotation about x-axis
     * Line 4: E: pixel size in the y-direction in map units, almost always negative[3]
     * Line 5: C: x-coordinate of the center of the upper left pixel
     * Line 6: F: y-coordinate of the center of the upper left pixel
     */
    if (debug) {
        System.out.println("A = " + A);
        System.out.println("D = " + D);
        System.out.println("B = " + B);
        System.out.println("E = " + E);
        System.out.println("C = " + C);
        System.out.println("F = " + F);

        // write the world file
        System.out.println();
        System.out.println("World File:");
        System.out.println(A);
        System.out.println(D);
        System.out.println(B);
        System.out.println(E);
        System.out.println(C);
        System.out.println(F);
    }

    // write to the .wld file
    wldWriter.write(A + "\n");
    wldWriter.write(D + "\n");
    wldWriter.write(B + "\n");
    wldWriter.write(E + "\n");
    wldWriter.write(C + "\n");
    wldWriter.write(F + "\n");

    wldWriter.close();
}

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