[marf-cvs] marf/src/marf/math Vector.java,NONE,1.1

[<mo...@us...>]

Update of /cvsroot/marf/marf/src/marf/math
In directory sc8-pr-cvs1:/tmp/cvs-serv18837

Added Files:
	Vector.java 
Log Message:
Add initial version of marf.math.Vector. Like Matrix, was conversted
from the same C++ code. So far remains unused (except test.java), but
eventually we might need it.


--- NEW FILE: Vector.java ---
package marf.math;

import marf.MARF;

/**
 * <p>Algebraic operations on vectors. Adapted from my graphics project written in C++.</p>
 * <p>$Header: /cvsroot/marf/marf/src/marf/math/Vector.java,v 1.1 2003/05/04 20:32:45 mokhov Exp $</p>
 * <p><b>NOTE:</b> this class has the same issues as marf.math.Matrix</p>
 *
 * @author Serguei A. Mokhov, mo...@cs...
 * @since 0.3.0
 * @see marf.math.Matrix
 */
public class Vector extends Matrix
{
	public static final int DEFAULT_VECTOR_LENGTH = 3;

	// Object Live Cycle
	public Vector()
	{
		this(DEFAULT_VECTOR_LENGTH);
	}

	public Vector(final int piVectorLength)
	{
		super(piVectorLength, 1);
	}

	public Vector(final Vector p_oVector)
	{
		super(p_oVector);
	}

	public Vector(final Matrix p_oMatrix)
	{
		super(p_oMatrix);
	}

	public Vector(final double[] padVectorData)
	{
		super(padVectorData);
	}

	// Vector Specific Operations

	public final double getElement(final int p_iPosition)
	{
		return m_iRows == 1 ?
			super.getElement(0, p_iPosition) :
			super.getElement(p_iPosition, 0);
	}

	public void setElement(final int p_iPosition, final double p_dValue)
	{
		if(m_iRows == 1)
		{
			super.setElement(0, p_iPosition, p_dValue);
		}
		else
		{
			super.setElement(p_iPosition, 0, p_dValue);
		}
	}

	public double getLength()
	{
		double l_dSqSum = 0.0;

		for(int i = 0; i < getElements(); i++)
		{
			l_dSqSum += m_pdMatrix[i] * m_pdMatrix[i];
		}

		return Math.sqrt(l_dSqSum);
	}

	public final Vector getUnitVector()
	{
		Vector l_oUnitVector = (Vector)this.clone();

		double l_dThisLength = l_oUnitVector.getLength();

		for(int i = 0; i < getElements(); i++)
		{
			l_oUnitVector.setElement(i, getElement(i) / l_dThisLength);
		}

		return l_oUnitVector;
	}

	public Vector getInnerProduct(final Vector p_oLHSVector, final Vector p_oRHSVector)
	{
		Vector l_oXVector = new Vector();

		l_oXVector.setElement(0, (p_oLHSVector.getElement(1) * p_oRHSVector.getElement(2) - p_oLHSVector.getElement(2) * p_oRHSVector.getElement(1)));
		l_oXVector.setElement(1, (p_oLHSVector.getElement(2) * p_oRHSVector.getElement(0) - p_oLHSVector.getElement(0) * p_oRHSVector.getElement(2)));
		l_oXVector.setElement(2, (p_oLHSVector.getElement(0) * p_oRHSVector.getElement(1) - p_oLHSVector.getElement(1) * p_oRHSVector.getElement(0)));

		return l_oXVector;
	}

	public Vector getCrossProduct(final Vector p_oLHSVector, final Vector p_oRHSVector)
	{
		MARF.debug("Vector.getInnerProduct() - WARNING: Implementation is incomplete!\n");

		if(p_oLHSVector.getElements() != p_oRHSVector.getElements())
		{
			return new Vector(0);
		}

		Vector l_oVectorIP = new Vector(p_oLHSVector.getElements());

		for(int i = 0; i < l_oVectorIP.getElements(); i++)
		{
			l_oVectorIP.setElement(i, p_oLHSVector.getElement(i) * p_oRHSVector.getElement(i));
		}

		return l_oVectorIP;
	}

	public double getDotProduct(final Vector p_oLHSVector, final Vector p_oRHSVector)
	{
		double l_dDotProduct = 0.0;

		if(p_oLHSVector.getElements() != p_oRHSVector.getElements())
		{
			MARF.debug("Vector.getDotProduct() - WARNING: Number of elements in vectors do not match: lhs="+p_oLHSVector.getElements()+", rhs="+p_oRHSVector.getElements()+"\n");
			return -1.0;
		}

		for(int i = 0; i < p_oLHSVector.getElements(); i++)
		{
			l_dDotProduct += p_oLHSVector.getElement(i) * p_oRHSVector.getElement(i);
		}

		return l_dDotProduct;
	}

	public boolean isOrthogonal(final Vector p_oVector)
	{
		return (getDotProduct(this, p_oVector) == 0);
	}

	public void normalize()
	{
		double l_dLength = getLength();

		// If fraction is too small
		// avoid division by zero
		// and just set all elements
		// to zero...
		if(Math.abs(l_dLength) < Double.MIN_VALUE)
		{
			setAll();
		}

		// ... or devide by length otherwise
		else
		{
			for(int i = 0; i < m_iCols * m_iRows; i++)
			{
				m_pdMatrix[i] /= l_dLength;
			}
		}
	}

	public final Vector i()
	{
		return new Vector(new double[] {1, 0, 0});
	}

	public final Vector j()
	{
		return new Vector(new double[] {0, 1, 0});
	}

	public final Vector k()
	{
		return new Vector(new double[] {0, 0, 1});
	}
}

// EOF