/**
 *  Computes altitude and azimuth from latitude, hour angle and declination.
 *  Glen Cowan, RHUL Physics
 *  16 October, 2003
 */

import java.io.*;

public class CoordCalc{
  public static void main (String[] args) throws IOException {

// Get phi, delta and h from console and convert from degrees to radians

    BufferedReader b = new BufferedReader(
                       new InputStreamReader(System.in));

    System.out.println("Enter latitude phi (degrees): ");
    double phi = Double.parseDouble ( b.readLine() ) * Math.PI / 180 ;

    System.out.println("Enter declination delta (degrees): ");
    double delta = Double.parseDouble ( b.readLine() ) * Math.PI / 180 ;

    System.out.println("Enter hour angle h (degrees): ");
    double h = Double.parseDouble ( b.readLine() ) * Math.PI / 180 ;

// Compute altitude

    double alt = Math.asin ( Math.cos(delta) * Math.cos(h) * Math.cos(phi) +
                           Math.sin(delta) * Math.sin(phi) );

// Now get sine and cosine of azimuth and use atan2 to figure out quadrant

    double sinAz =  - Math.cos(delta) * Math.sin(h) / Math.cos(alt) ;
    double cosAz = ( - Math.cos(delta) * Math.cos(h) * Math.sin(phi)
                     + Math.sin(delta) * Math.cos(phi) ) / Math.cos(alt) ;
    double Az = Math.atan2(sinAz, cosAz);

// Convert to degrees and output to screen

    System.out.println("altitude = " + alt*180/Math.PI + " degrees");
    System.out.println("Azimuth  = " + Az*180/Math.PI + " degrees");

  }
}