Example usage for java.lang Math sqrt

Introduction

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

Prototype

@HotSpotIntrinsicCandidate
public static double sqrt(double a)

Source Link

Document

Returns the correctly rounded positive square root of a double value.

Usage

From source file:Main.java

public static Bitmap resizeDownToPixels(Bitmap bitmap, int targetPixels, boolean recycle) {
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();
    float scale = (float) Math.sqrt((double) targetPixels / (width * height));
    if (scale >= 1.0f)
        return bitmap;
    return resizeBitmapByScale(bitmap, scale, recycle);
}

From source file:Main.java

public static boolean isTablet(Context ctx) {
    try {//from  ww  w. j a v a 2 s .c  om
        DisplayMetrics dm = ctx.getResources().getDisplayMetrics();
        float screenWidth = dm.widthPixels / dm.xdpi;
        float screenHeight = dm.heightPixels / dm.ydpi;
        double size = Math.sqrt(Math.pow(screenWidth, 2) + Math.pow(screenHeight, 2));
        return size >= 6;
    } catch (Throwable t) {
        return false;
    }
}

From source file:Main.java

private static int computeInitialSampleSize(BitmapFactory.Options options, int minSideLength,
        int maxNumOfPixels) {
    double w = options.outWidth;
    double h = options.outHeight;

    int lowerBound = (maxNumOfPixels < 0) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
    int upperBound = (minSideLength < 0) ? 128
            : (int) Math.min(Math.floor(w / minSideLength), Math.floor(h / minSideLength));

    if (upperBound < lowerBound) {
        // return the larger one when there is no overlapping zone.
        return lowerBound;
    }/* www .  j  a v  a2  s.  c  om*/

    if (maxNumOfPixels < 0 && minSideLength < 0) {
        return 1;
    } else if (minSideLength < 0) {
        return lowerBound;
    } else {
        return upperBound;
    }
}

From source file:Main.java

public static void transform(double wgLat, double wgLon, double[] latlng) {
    if (outOfChina(wgLat, wgLon)) {
        latlng[0] = wgLat;/*w  w w  .  ja va2 s. c  o m*/
        latlng[1] = wgLon;
        return;
    }
    double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
    double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
    double radLat = wgLat / 180.0 * pi;
    double magic = Math.sin(radLat);
    magic = 1 - ee * magic * magic;
    double sqrtMagic = Math.sqrt(magic);
    dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
    dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
    latlng[0] = wgLat + dLat;
    latlng[1] = wgLon + dLon;
}

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 v  a 2s  .  c o m
    s = Math.round(s * 10000d) / 10000d;
    s = s * 1000;
    return s;
}

From source file:IsPrimeOld.java

private static void initPrimeList() {

    long start = System.currentTimeMillis();
    if (maxNumber == 3) {
        primeList.add(2L);/*from w w  w.  j  av a  2  s .c om*/
        primeList.add(3L);
    }
    for (long i = maxNumber; i < newMaxNumber; i += 2) {
        long j = 1;
        double temp = Math.sqrt(i);
        for (j = 2; j < temp; j++) {
            if (i % j == 0)
                break;
        }
        if (j == (long) temp + 1) {
            primeList.add(i);
        }
    }
    long end = System.currentTimeMillis();
    maxNumber = newMaxNumber;
}

From source file:Main.java

private static int computeInitialSampleSize(int w, int h, int minSideLength, int maxNumOfPixels) {
    if (maxNumOfPixels == UNCONSTRAINED && minSideLength == UNCONSTRAINED)
        return 1;

    int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1
            : (int) Math.ceil(Math.sqrt((double) (w * h) / maxNumOfPixels));

    if (minSideLength == UNCONSTRAINED) {
        return lowerBound;
    } else {/*w w  w. j  a  v a  2s .  c  o  m*/
        int sampleSize = Math.min(w / minSideLength, h / minSideLength);
        return Math.max(sampleSize, lowerBound);
    }
}

From source file:Main.java

private static int computeInitialSampleSize(int w, int h, int minSideLength, int maxNumOfPixels) {
    if (maxNumOfPixels == UNCONSTRAINED && minSideLength == UNCONSTRAINED)
        return 1;

    int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1
            : (int) Math.ceil(Math.sqrt((float) (w * h) / maxNumOfPixels));

    if (minSideLength == UNCONSTRAINED) {
        return lowerBound;
    } else {//from  w  w w.j a  va 2  s .  com
        int sampleSize = Math.min(w / minSideLength, h / minSideLength);
        return Math.max(sampleSize, lowerBound);
    }
}

From source file:Main.java

public static double confval(int N, double alfa, double std) {
    return zn(alfa) * (std / Math.sqrt((double) N));
}

From source file:Main.java

static public String whyNotPrimeNumber(int num) {
    if (num <= 0) {
        return "0 and negative numbers are not Prime";
    }//from   www . j  a  v a 2s .  c  om
    if (num == 1) {
        return "1 is not prime number";
    }

    for (int i = (int) Math.sqrt(num); i > 1; i--) {
        if (num % i == 0) {
            return num + " = " + i + " X " + num / i;
        }
    }
    return null;
}