protected double calculateSeriesWidth(double space,CategoryAxis axis,int categories,int series){
  double factor=1.0 - getItemMargin() - axis.getLowerMargin()- axis.getUpperMargin();
  if (categories > 1) {
    factor=factor - axis.getCategoryMargin();
  }
  return (space * factor) / (categories * series);
}

protected double calculateSeriesWidth ( double space , CategoryAxis axis , int categories , int series ) { double factor = 1.0 - getItemMargin ( ) - axis . getLowerMargin ( ) - axis . getUpperMargin ( ) ; if ( categories > 1 ) { factor = factor - axis . getCategoryMargin ( ) ; } return ( space * factor ) / ( categories * series ) ; }
calculates the available space for each series .
