|
/*
* This file is part of JGAP.
*
* JGAP offers a dual license model containing the LGPL as well as the MPL.
*
* For licensing information please see the file license.txt included with JGAP
* or have a look at the top of class org.jgap.Chromosome which representatively
* includes the JGAP license policy applicable for any file delivered with JGAP.
*/
/**
* Utility routines related to numbers.
*
* @author Klaus Meffert
* @since 3.2
*/
public class NumberKit {
/**
* Returns the hex value of "c" or -1 if there is no corresponding hex value.
*
* @param a_c hex character to convert
* @return integer value of the character
*
* @author unknown
* @since 3.2
*/
public static int hexValue(char a_c) {
if ('0' <= a_c && a_c <= '9') {
return a_c - '0';
}
if ('A' <= a_c && a_c <= 'F') {
return a_c - 'A' + 10;
}
if ('a' <= a_c && a_c <= 'f') {
return a_c - 'a' + 10;
}
return -1;
}
private static final char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
/**
* Transforms a byte to a character array of hex octets.
* Taken from UUID.
*
* @param a_in the byte
* @return the hex byte array
*/
public static char[] asChars(byte a_in) {
return asChars(a_in, 2);
}
/**
* Transforms a byte to a character array of hex octets.
* Taken from UUID.
*
* @param a_in the byte
* @param a_length the number of octets to produce
* @return the hex byte array
*/
public static char[] asChars(byte a_in, int a_length) {
char[] out = new char[a_length--];
for (int i = a_length; i > -1; i--) {
out[i] = DIGITS[ (byte) (a_in & 0x0F)];
a_in >>= 4;
}
return out;
}
/**
* Parses a short from a hex encoded number. This method will skip
* all characters that are not 0-9 and a-f (the String is lower cased first).
*
* @param s the String to extract a short from, may not be null
* @return 0 if the String does not contain any interesting characters
* @throws NullPointerException if the String is null
*
* @since 3.3.3
*/
public static short parseShort(String s)
throws NullPointerException {
s = s.toLowerCase();
short out = 0;
byte shifts = 0;
char c;
for (int i = 0; i < s.length() && shifts < 4; i++) {
c = s.charAt(i);
if ( (c > 47) && (c < 58)) {
out <<= 4;
++shifts;
out |= c - 48;
}
else if ( (c > 96) && (c < 103)) {
++shifts;
out <<= 4;
out |= c - 87;
}
}
return out;
}
/**
* Formats a number as a string having the total length of a_places, filling
* up needed characters with a_filler.
*
* @param a_number the number to format
* @param a_places total length of output string
* @param a_filler fill character
* @return formatted number
*
* @author Klaus Meffert
* @since 3.3.3
*/
public static String niceNumber(int a_number, int a_places, char a_filler) {
String s = a_number + "";
while (s.length() < a_places) {
s = a_filler + s;
}
return s;
}
/**
* Removes decimal places if there are more than a_decimals.
*
* @param a_number the number to convert to a string
* @param a_decimals maximum number of decimal places allowed
*
* @return nicified string
*
* @author Klaus Meffert
* @since 3.3.3
*/
public static String niceDecimalNumber(double a_number, int a_decimals) {
String s = a_number + "";
int index = s.indexOf('.');
if (index > 0) {
// Do not remove anything if "E" is contained in the number string.
// ----------------------------------------------------------------
if (s.indexOf('E',index) > 0) {
return s;
}
if (index + a_decimals >= s.length()) {
a_decimals = s.length() - index - 1;
}
s = s.substring(0, index + a_decimals + 1);
if (s.lastIndexOf('.') == s.length() - 1) {
if (a_decimals < 1) {
s = s.substring(0, s.length() - 1);
}
else {
for (int i = 0; i < a_decimals; i++) {
s += "0";
}
}
}
}
return s;
}
}
|