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Copyright Tristan Aubrey-Jones December 2005.
package tajy;
public class Vector
{
double x, y;
public Vector(double x, double y)
{
this.x = x;
this.y = y;
}
public Vector(Vector v)
{
this.x = v.x;
this.y = v.y;
}
private static double getGoodDegrees(double angle)
{
return angle % 360;
}
public double getX()
{
return x;
}
public double getY()
{
return y;
}
public void setX(double x)
{
this.x = x;
}
public void setY(double y)
{
this.y = y;
}
public double getBearingRadians()
{
double angle = Math.atan(x / y);
// -x
if (x < 0)
{
// -y
if (y < 0)
{
return angle + Math.PI;
}
// +y
else
{
return angle + 2 * Math.PI;
}
}
// +x
else
{
// -y
if (y < 0)
{
return angle + Math.PI;
}
// +y
else
{
return angle;
}
}
}
public double getBearingDegrees()
{
double angle = Math.toDegrees(getBearingRadians());
if (angle < 0) return angle + 360;
else return angle;
}
public double getDistance()
{
// make sure are positive
double x = this.x; if (x < 0) x = -x;
double y = this.y; if (y < 0) y = -y;
// return magnitude |r| of vector
return Math.sqrt((x*x) + (y*y));
}
public Vector add(Vector v)
{
return new Vector(x + v.x, y + v.y);
}
/**
* @param angle - Angle in radians from the +ve y axis
* @param distance - distance along line to travel
* @return A vector representing that movement
*/
public static Vector fromAngleRadians(double angle, double distance)
{
Vector r = new Vector(0, 0);
r.x = distance * Math.sin(angle);
r.y = distance * Math.cos(angle);
return r;
}
/**
* @param angle - Angle in degrees from the +ve y axis
* @param distance - distance along line to travel
* @return A vector representing that movement
*/
public static Vector fromAngleDegrees(double angle, double distance)
{
angle = Vector.getGoodDegrees(angle);
return fromAngleRadians(Math.toRadians(angle), distance);
}
public Vector subtract(Vector v)
{
return new Vector(x - v.x, y - v.y);
}
public double dotProduct(Vector v)
{
return (x * v.x) + (y * v.y);
}
public String toString()
{
return '(' + Double.toString(x) + ", " + Double.toString(y) + ')';
}
public double distanceTo(Vector v)
{
Vector r = v.subtract(this);
return r.getDistance();
}
}