src/main/java/de/javagl/geom/Lines.java
/**
     * Computes the angle, in radians, between the given lines, as a value
     * between 0 and 2PI.
     * 
     * @param s0 The start point of the first line
     * @param e0 The end point of the first line 
     * @param s1 The start point of the second line
     * @param e1 The end point of the second line
     * @return The angle, in radians, between the given lines
     */
Computes the angle, in radians, between the given lines, as a value
between 0 and 2PI.


Computes the angle in radians between the given lines as a value between 0 and 2PI .
public static double angle(
        Point2D s0, Point2D e0, Point2D s1, Point2D e1)
    {
        return normalizeAngle(angleToX(s1, e1) - angleToX(s0, e0));
    }
public static double angle ( Point2D s0 , Point2D e0 , Point2D s1 , Point2D e1 ) { return normalizeAngle ( angleToX ( s1 , e1 ) - angleToX ( s0 , e0 ) ) ; }
Computes the angle, in radians, between the given lines, as a value
 between 0 and 2PI.
Computes the angle in radians between the given lines as a value between 0 and 2PI .