lcsim/sandbox/RobKutschke

diff -N cyl_int.java
--- cyl_int.java	30 Aug 2007 14:13:09 -0000	1.1
+++ /dev/null	1 Jan 1970 00:00:00 -0000
@@ -1,124 +0,0 @@

-import java.lang.Math;
-
-/**
- * 
- * Find the interesection of a track, specified by the CLEO paramters
- * with the a cylinder of radius r, centered on the origin.
- *
- *@author $Author: kutschke $
- *@version $Id: cyl_int.java,v 1.1 2007/08/30 14:13:09 kutschke Exp $
- *
- * Date $Date: 2007/08/30 14:13:09 $
- *
- */
-
-public class cyl_int{
-
-    private double x;
-    private double y;
-    private double psi;
-
-    private double k;
-    private double d0;
-    private double phi;
-    private double z;
-    private double t;
-
-    private double q;
-    private double rho;
-
-    public cyl_int( double k, 
-		    double d0, 
-		    double phi, 
-		    double z, 
-		    double t, 
-		    double r
-		    ){
-
-	this.k   = k;
-	this.d0  = d0;
-	this.phi = phi;
-	this.z   = z;
-	this.t   = t;
-
-	// Some other quantities derived from the track parameters.
-
-	q   =  (k > 0 ) ? 1.0 : -1.0;
-	rho = Math.abs( 0.5/k );
-
-
-	double u0   =  Math.cos(phi);
-	double v0   =  Math.sin(phi);
-	double x0   = -d0 * v0;
-	double y0   =  d0 * u0;
-
-	double x0t  = x0-q*rho*v0;
-	double y0t  = y0+q*rho*u0;
-
-	double dpsi = Math.atan2(-y0t,x0t);
-	
-	double sang = (r*r-x0t*x0t-y0t*y0t-rho*rho)/
-	    (2.*q*rho*Math.sqrt(x0t*x0t+y0t*y0t));
-	if ( sang > 1.0 ){
-	    sang = 1.0; 
-	}else if ( sang < -1.0 ){
-	    sang = -1.0;
-	}
-
-	double psi1=(Math.asin(sang)-phi-dpsi);
-	double psi2=(Math.PI-Math.asin(sang)-phi-dpsi);
-
-	double twopi = 2.*Math.PI;
-
-	// Put angles in the correct quadrant.
-	if (psi1 > twopi){
-	    psi1 -= twopi;
-	}
-	if (psi1 < 0.0) {
-	    psi1 += twopi;
-	}
-	if (psi1 < 0.0) {
-	    psi1 += twopi;
-	}
-	
-	if (psi2 > twopi) {
-	    psi2 -= twopi;
-	}
-	if (psi2 < 0.0) {
-	    psi2 += twopi;
-	}
-	if (psi2 < 0.0) {
-	    psi2 += twopi;
-	}
-
-	psi = ( psi2 < psi1) ? psi2 : psi1;
-	
-	x = x0t + q*rho*Math.sin(phi+q*psi);
-	y = y0t - q*rho*Math.cos(phi+q*psi);
-    }
-    
-    double getX(){
-	return x;
-    }
-
-    double getY(){
-	return y;
-    }
-
-    double getZ(){
-	double cz = t / Math.sqrt( 1. + t*t );
-	return z + rho*psi*t;
-    }
-
-
-    double getPsi(){
-	return psi;
-    }
-
-
-}
-
-
-
-
-