Tools.java

package ij.util;
import java.awt.Color;

 public class Tools {
    public static final char[] hexDigits = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    
    public static String c2hex(Color c) {
        int i = c.getRGB();
        char[] buf7 = new char[7];
        buf7[0] = '#';
        for (int pos=6; pos>=1; pos--) {
            buf7[pos] = hexDigits[i&0xf];
            i >>>= 4;
        }
        return new String(buf7);
    }
        
    public static String f2hex(float f) {
        int i = Float.floatToIntBits(f);
        char[] buf9 = new char[9];
        buf9[0] = '#';
        for (int pos=8; pos>=1; pos--) {
            buf9[pos] = hexDigits[i&0xf];
            i >>>= 4;
        }
        return new String(buf9);
    }
        
    public static double[] getMinMax(double[] a) {
        double min = Double.MAX_VALUE;
        double max = -Double.MAX_VALUE;
        double value;
        for (int i=0; i<a.length; i++) {
            value = a[i];
            if (value<min)
                min = value;
            if (value>max)
                max = value;
        }
        double[] minAndMax = new double[2];
        minAndMax[0] = min;
        minAndMax[1] = max;
        return minAndMax;
    }

    public static double[] getMinMax(float[] a) {
        double min = Double.MAX_VALUE;
        double max = -Double.MAX_VALUE;
        double value;
        for (int i=0; i<a.length; i++) {
            value = a[i];
            if (value<min)
                min = value;
            if (value>max)
                max = value;
        }
        double[] minAndMax = new double[2];
        minAndMax[0] = min;
        minAndMax[1] = max;
        return minAndMax;
    }
    
    public static double[] toDouble(float[] a) {
        int len = a.length;
        double[] d = new double[len];
        for (int i=0; i<len; i++)
            d[i] = a[i];
        return d;
    }
    
    public static float[] toFloat(double[] a) {
        int len = a.length;
        float[] f = new float[len];
        for (int i=0; i<len; i++)
            f[i] = (float)a[i];
        return f;
    }
    
    public static String fixNewLines(String s) {
        char[] chars = s.toCharArray();
        for (int i=0; i<chars.length; i++)
            {if (chars[i]=='\r') chars[i] = '\n';}
        return new String(chars);
    }

    public static double parseDouble(String s, double defaultValue) {
        try {
            Double d = new Double(s);
            defaultValue = d.doubleValue();
        } catch (NumberFormatException e) {}
        return defaultValue;            
    }

    public static double parseDouble(String s) {
        return parseDouble(s, Double.NaN);
    }
    
    public static int getDecimalPlaces(double n1, double n2) {
        if (Math.round(n1)==n1 && Math.round(n2)==n2)
            return 0;
        else {
            n1 = Math.abs(n1);
            n2 = Math.abs(n2);
            double n = n1<n2&&n1>0.0?n1:n2;
            double diff = Math.abs(n2-n1);
            if (diff>0.0 && diff<n) n = diff;           
            int digits = 2;
            if (n<100.0) digits = 3;
            if (n<0.1) digits = 4;
            if (n<0.01) digits = 5;
            if (n<0.001) digits = 6;
            if (n<0.0001) digits = 7;
            return digits;
        }
    }

}