protected double computeMaxYAxisValueLogScale(double maxValue){
  double v=0;
  int mantisse=0;
  int exponent=0;
  while (v < maxValue) {
    if (mantisse < 9)     mantisse++;
 else {
      mantisse=1;
      exponent++;
    }
    v=mantisse * Math.pow(10,exponent);
  }
  return Math.log10(v);
}

protected double computeMaxYAxisValueLogScale ( double maxValue ) { double v = 0 ; int mantisse = 0 ; int exponent = 0 ; while ( v < maxValue ) { if ( mantisse < 9 ) mantisse ++ ; else { mantisse = 1 ; exponent ++ ; } v = mantisse * Math . pow ( 10 , exponent ) ; } return Math . log10 ( v ) ; }
compute the maximum value on a log scale
