Example usage for java.lang Math log

Introduction

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

Prototype

@HotSpotIntrinsicCandidate
public static double log(double a)

Source Link

Document

Returns the natural logarithm (base e) of a double value.

Usage

From source file:Main.java

public static String ReadableByteCount(long bytes) {
    int unit = 1024;
    if (bytes < unit)
        return bytes + " B";
    int exp = (int) (Math.log(bytes) / Math.log(unit));
    String pre = String.valueOf("KMGTPE".charAt(exp - 1));
    return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
}

From source file:Main.java

public static String formatBits(long bytes) {
    int unit = 1024;
    if (bytes < unit)
        return bytes + " B";
    int exp = (int) (Math.log(bytes) / Math.log(unit));
    String pre = ("KMGTPE").charAt(exp - 1) + "";
    return String.format(Locale.ENGLISH, "%.1f %sb", bytes / Math.pow(unit, exp), pre);
}

From source file:Main.java

public static BitmapFactory.Options createBitmapScaledOptions(int targetResolution, int actualResolution) {
    double scaleFactor = Math.log((double) actualResolution / (double) targetResolution) / Math.log(2);

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize = Math.max(1, (int) Math.floor(scaleFactor));

    return options;
}

From source file:Main.java

public static String formatBytes(long bytes) {
    int unit = 1024;
    if (bytes < unit)
        return bytes + " B";
    int exp = (int) (Math.log(bytes) / Math.log(unit));
    String pre = ("KMGTPE").charAt(exp - 1) + "";
    return String.format(Locale.ENGLISH, "%.1f %sB", bytes / Math.pow(unit, exp), pre);
}

From source file:Main.java

public static String humanReadableByteCount(long bytes, boolean si) {
    int unit = si ? 1000 : 1024;
    if (bytes < unit)
        return bytes + " B";
    int exp = (int) (Math.log(bytes) / Math.log(unit));
    String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp - 1) + (si ? "" : "i");
    return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
}

From source file:Main.java

private static String humanReadableByteCount(long bytes, boolean si) {
    int unit = si ? 1000 : 1024;
    if (bytes < unit)
        return bytes + " B";
    int exp = (int) (Math.log(bytes) / Math.log(unit));
    String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp - 1) + (si ? "" : "i");
    return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
}

From source file:Main.java

public static double calculateMinZoomLevel(int width, int height, int tileSize) {
    int max = Math.max(width, height);
    int tilesCount = (int) Math.ceil(1d * max / tileSize);
    return Math.ceil(Math.log(tilesCount) / Math.log(2d));
}

From source file:Main.java

public static String humanReadableByteCount(long bytes, boolean si) {
    int unit = si ? 1000 : 1024;
    if (bytes < unit) {
        return bytes + " B";
    }//from  w w  w.ja va 2 s.  c  o  m
    final int exp = (int) (Math.log(bytes) / Math.log(unit));
    final String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp - 1) + (si ? "" : "i");
    return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
}

From source file:Main.java

public static Bitmap createPOT(Bitmap bmp) {
    Bitmap potBmp = null;// www. j a v a2 s  .  c om
    int potWidth = (int) Math.ceil(Math.log(bmp.getWidth()) / Math.log(2));
    int potHeight = (int) Math.ceil(Math.log(bmp.getHeight()) / Math.log(2));
    potHeight = (int) Math.pow(2, potHeight);
    potWidth = (int) Math.pow(2, potWidth);

    if (potWidth == 1) {
        potWidth = 2;
    }
    if (potHeight == 1) {
        potHeight = 2;
    }

    if (potHeight != bmp.getHeight() || potWidth != bmp.getWidth()) {
        int[] colors = new int[potWidth * potHeight];
        int index = 0;

        int offset = potHeight - bmp.getHeight();
        for (int i = 0; i < potHeight; i++) {
            for (int j = 0; j < potWidth; j++) {
                if (i > offset - 1) {
                    if (j < bmp.getWidth() && i < bmp.getHeight()) {
                        colors[index] = bmp.getPixel(j, i);
                    } else {
                        colors[index] = 0;
                    }
                }
                index++;
            }
        }

        potBmp = Bitmap.createBitmap(colors, potWidth, potHeight, bmp.getConfig());
    } else {
        potBmp = bmp;
    }

    System.gc();

    return potBmp;
}

From source file:Main.java

public static String getSigFig(double value, int n) {
    String result = String.format("%.10f", value);
    int k = (int) (Math.log(Math.abs(value)) / Math.log(10));
    if ((k + 1) >= n) {
        // Assume value > 0
        result = result.substring(0, n);
    } else {//from   www. j av  a  2  s.  c o m
        if (value < 0) {
            n = n + 1;
        }
        if (0 < Math.abs(value) && Math.abs(value) < 1) {
            n = n + 1;
        }
        if (value != 0) {
            result = result.substring(0, n + 1);
        } else {
            n = n + 2;
            result = "0.0";
        }
        // Add trailing zeros
        while (result.length() < n) {
            result = result + "0";
        }
    }
    return result;
}