/**************************************************************************
 *   Copyright (C) 2008, Paul Lutus                                        *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

import java.io.*;

public class TankVolume {
  
  static double horizontal_tank_volume(double L,double R,double r,double y) {
    double v = -1.0;
    if(y >= 0.0 && y <= 2.0*R) {
      double a = (Math.PI * r * (3.0 * R - y)*y*y)/(3.0 * R);
      double q = 1.0 / Math.sqrt((2.0 * R / y)-1.0);
      double b = 2.0 * Math.atan(q) * R * R;
      double c = Math.sqrt((2.0 * R-y) * y) * (y-R);
      v = a + L * (b + c);
    }
    return v;
  }
  
  static double vertical_tank_volume(double L,double R,double r,double y) {
    double v = -1.0;
    if(0.0 <= y && y < r) {
      v = (Math.PI*R*R*(3.0*r-y)*y*y)/(3.0*r*r);
    }
    else if(r <= y && y < r+L) {
      v = -(Math.PI*R*R/3.0)*(r-3.0*y);
    }
    else if (r+L <= y && y <= 2.0*r+L) {
      v = (Math.PI*R*R/3.0)*((((L+3.0*r-y)*(L-y)*(L-y))/(r*r))+3.0*L);
    }
    return v;
  }
  
  static void compute_volume(double L,double R,double r,boolean vert,double y) {
    double v;
    if(vert) {
      v = vertical_tank_volume(L,R,r,y);
    }
    else {
      v = horizontal_tank_volume(L,R,r,y);
    }
    System.out.println(y + "," + v);
  }
  
  static public void main(String[] args) throws Exception {
    if(args.length < 4 || (!args[0].equals("h") && !args[0].equals("v"))) {
      System.out.println("Usage: (h/v) (horizontal/vertical)");
      System.out.println("       L (cylinder length)");
      System.out.println("       R (cylinder radius/ellipse major radius)");
      System.out.println("       r (ellipse minor radius)");
      System.out.println("       [optional step size, default 1.0]");
      System.out.println("       All consistent units.");
      System.out.println("Result:  data table of tank content heights and volumes in units^3.");
    }
    else {
      boolean vert = (args[0].equals("v"));
      double L = Double.parseDouble(args[1]);
      double R = Double.parseDouble(args[2]);
      double r = Double.parseDouble(args[3]);
      double step = (args.length > 4)?Double.parseDouble(args[4]):1.0;
      double y;
      double top = (vert)?L+(2*r):2*R;
      int i = 1;
      System.out.println("Height,Volume");
      while((y = i * step) < top) {
        compute_volume(L,R,r,vert,y);
        i++;
      }
      compute_volume(L,R,r,vert,top);
    }
  }
};