import java.lang.Math;

/**===========================================================<BR>
* Determines tick values:<P>
* (First tick value, Last Tick value, distance between two tick)<BR>
* such that the given intervalle has about 10 ticks
*============================================================*/
public class Scale {
 private static double rap[]={10.0, 5.0, 2.0, 1.0, 0.5, 0.2, 0.1};
 private final double loga10 = 2.302585093;
 private double Decc;
 private double expo;
 private int NX1, NX2;
 
 /** First tick value */
 public double getMin() {return(NX1 * Decc);}
 
 /** Last tick value */
 public double getMax() {return(NX2 * Decc);}
 
 /** Intervalle between two ticks*/
 public double getStep() {return(Decc);}

 /** Specify entire intervalle*/
 public void setMinMax(double m, double M)
	{double Xmin = m; 
	double Xmax = M;
  
	if(Xmax == Xmin) Xmax += 1.0;
	int mult = (int)Math.floor(Math.log(Xmax - Xmin) / loga10);

	Decc = (Xmax - Xmin) / Math.pow(10.0, mult);
 
	double n;
	int i = 0;
	do
		n = Decc / rap[i++];
	while (n <= 8 && i<7);
	i -= 2;
	Decc = rap[i] * Math.pow(10.0, mult);
	
	NX2 = (int)Math.floor(Xmax / Decc);
	NX1 = (int)Math.floor(Xmin / Decc) + 1;
	if(Math.abs(Xmin - (double)(NX1 - 1) * Decc) < .01 * Decc) NX1 -= 1;
	if(Math.abs(Xmax - (double)(NX2 + 1) * Decc) < .01 * Decc) NX2 += 1;
	 
	if(NX1 == 0 || NX2 == 0) {expo = 0; return;}
	
	expo = (int)Math.floor(Math.log(Math.abs((double)NX2) * Decc)/loga10);
	int b = (int)Math.floor(Math.log(Math.abs((double)NX1) * Decc)/loga10);
	if( b < expo) expo = b;
	int c = (int)Math.floor(Math.log((double)(NX2-NX1) * Decc)/loga10) + 1;
	if( c < expo) expo = c;
	}

/** Constructor specifies default entire intervalle*/
 public Scale(double m, double M)
	{setMinMax(m,M);}
}