samer@0: /*
samer@0:  *	DoubleFormat.java	
samer@0:  *
samer@0:  *	Copyright (c) 2000, Samer Abdallah, King's College London.
samer@0:  *	All rights reserved.
samer@0:  *
samer@0:  *	This software is provided AS iS and WITHOUT ANY WARRANTY; 
samer@0:  *	without even the implied warranty of MERCHANTABILITY or 
samer@0:  *	FITNESS FOR A PARTICULAR PURPOSE.
samer@0:  */
samer@0: 
samer@0: package samer.core;
samer@0: import  java.text.*;
samer@0: 
samer@0: public class DoubleFormat extends NumberFormat
samer@0: {
samer@0: 	int nfix=2;
samer@0: 
samer@0: 	public DoubleFormat(int n) { setDecimals(n); }
samer@0: 
samer@0: 	public void   setDecimals(int n) { nfix=n; }
samer@0: 	public String _format(double x) { return format(x,nfix); }
samer@0: 	public double _parse(String s) { return Double.valueOf(s).doubleValue(); }
samer@0: 
samer@0: 
samer@0: 	public StringBuffer format( long n, StringBuffer buf, FieldPosition fp) {
samer@0: 		buf.append(n);
samer@0: 		return buf;
samer@0: 	}
samer@0: 	public StringBuffer format( double x, StringBuffer buf, FieldPosition fp) {
samer@0: 		buf.append(x);
samer@0: 		return buf;
samer@0: 	}
samer@0: 
samer@0: 	public Number parse(String s, java.text.ParsePosition pp) {
samer@0: 		return Double.valueOf(s);
samer@0: 	}
samer@0: 	// ...............................................
samer@0: 
samer@0: 	public static String format( double x, int nfix)
samer@0: 	{
samer@0: 		int nfixPlus1=nfix+1;
samer@0: 		// quick and dirty hack!
samer@0: 		String s=Double.toString(x);
samer@0: 		int	point = s.indexOf('.');
samer@0: 
samer@0: 		// no decimals: return as is
samer@0: 		if (point==-1) return s;
samer@0: 
samer@0: 		// look for exponent
samer@0: 		int	exp = s.indexOf('E',point);
samer@0: 
samer@0: 		if (exp==-1) {
samer@0: 			// no exponent: count decimals
samer@0: 			if (s.length()-point <= nfixPlus1) return s;
samer@0: 			else {
samer@0: 				// chop off excess precision
samer@0: 				return s.substring(0,point+nfixPlus1);
samer@0: 			}
samer@0: 		} else {
samer@0: 			// count digits up to exponent
samer@0: 			if (exp-point < nfixPlus1) return s;
samer@0: 			else {
samer@0: 				// return truncated mantissa and exponent
samer@0: 				return s.substring(0,point+nfixPlus1) + s.substring(exp);
samer@0: 			}
samer@0: 		}
samer@0: 	}
samer@0: }