/*
* $RCSfile$
*
* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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*/
package com.android.droidgraph.vecmath;
import java.lang.Math;
/**
* A double precision, general, dynamically-resizable,
* one-dimensional vector class. Index numbering begins with zero.
*/
public class GVector implements java.io.Serializable, Cloneable {
private int length;
double[] values;
// Compatible with 1.1
static final long serialVersionUID = 1398850036893875112L;
/**
* Constructs a new GVector of the specified
* length with all vector elements initialized to 0.
* @param length the number of elements in this GVector.
*/
public GVector(int length)
{
int i;
this.length = length;
values = new double[length];
for(i = 0; i < length; i++) values[i] = 0.0;
}
/**
* Constructs a new GVector from the specified array elements.
* The length of this GVector is set to the length of the
* specified array. The array elements are copied into this new
* GVector.
* @param vector the values for the new GVector.
*/
public GVector(double[] vector)
{
int i;
length = vector.length;
values = new double[vector.length];
for(i = 0; i < length; i++) values[i] = vector[i];
}
/**
* Constructs a new GVector from the specified vector.
* The vector elements are copied into this new GVector.
* @param vector the source GVector for this new GVector.
*/
public GVector(GVector vector)
{
int i;
values = new double[vector.length];
length = vector.length;
for(i = 0; i < length; i++) values[i] = vector.values[i];
}
/**
* Constructs a new GVector and copies the initial values
* from the specified tuple.
* @param tuple the source for the new GVector's initial values
*/
public GVector(Tuple2f tuple)
{
values = new double[2];
values[0] = (double)tuple.x;
values[1] = (double)tuple.y;
length = 2;
}
/**
* Constructs a new GVector and copies the initial values
* from the specified tuple.
* @param tuple the source for the new GVector's initial values
*/
public GVector(Tuple3f tuple)
{
values = new double[3];
values[0] = (double)tuple.x;
values[1] = (double)tuple.y;
values[2] = (double)tuple.z;
length = 3;
}
/**
* Constructs a new GVector and copies the initial values
* from the specified tuple.
* @param tuple the source for the new GVector's initial values
*/
public GVector(Tuple3d tuple)
{
values = new double[3];
values[0] = tuple.x;
values[1] = tuple.y;
values[2] = tuple.z;
length = 3;
}
/**
* Constructs a new GVector and copies the initial values
* from the specified tuple.
* @param tuple the source for the new GVector's initial values
*/
public GVector(Tuple4f tuple)
{
values = new double[4];
values[0] = (double)tuple.x;
values[1] = (double)tuple.y;
values[2] = (double)tuple.z;
values[3] = (double)tuple.w;
length = 4;
}
/**
* Constructs a new GVector and copies the initial values
* from the specified tuple.
* @param tuple the source for the new GVector's initial values
*/
public GVector(Tuple4d tuple)
{
values = new double[4];
values[0] = tuple.x;
values[1] = tuple.y;
values[2] = tuple.z;
values[3] = tuple.w;
length = 4;
}
/**
* Constructs a new GVector of the specified length and
* initializes it by copying the specified number of elements from
* the specified array. The array must contain at least
* <code>length</code> elements (i.e., <code>vector.length</code> >=
* <code>length</code>. The length of this new GVector is set to
* the specified length.
* @param vector The array from which the values will be copied.
* @param length The number of values copied from the array.
*/
public GVector(double vector[], int length) {
int i;
this.length = length;
values = new double [length];
for(i=0;i<length;i++) {
values[i] = vector[i];
}
}
/**
* Returns the square root of the sum of the squares of this
* vector (its length in n-dimensional space).
* @return length of this vector
*/
public final double norm()
{
double sq = 0.0;
int i;
for(i=0;i<length;i++) {
sq += values[i]*values[i];
}
return(Math.sqrt(sq));
}
/**
* Returns the sum of the squares of this
* vector (its length squared in n-dimensional space).
* @return length squared of this vector
*/
public final double normSquared()
{
double sq = 0.0;
int i;
for(i=0;i<length;i++) {
sq += values[i]*values[i];
}
return(sq);
}
/**
* Sets the value of this vector to the normalization of vector v1.
* @param v1 the un-normalized vector
*/
public final void normalize(GVector v1)
{
double sq = 0.0;
int i;
if( length != v1.length)
throw new MismatchedSizeException(VecMathI18N.getString("GVector0"));
for(i=0;i<length;i++) {
sq += v1.values[i]*v1.values[i];
}
double invMag;
invMag = 1.0/Math.sqrt(sq);
for(i=0;i<length;i++) {
values[i] = v1.values[i]*invMag;
}
}
/**
* Normalizes this vector in place.
*/
public final void normalize()
{
double sq = 0.0;
int i;
for(i=0;i<length;i++) {
sq += values[i]*values[i];
}
double invMag;
invMag = 1.0/Math.sqrt(sq);
for(i=0;i<length;i++) {
values[i] = values[i]*invMag;
}
}
/**
* Sets the value of this vector to the scalar multiplication
* of the scale factor with the vector v1.
* @param s the scalar value
* @param v1 the source vector
*/
public final void scale(double s, GVector v1)
{
int i;
if( length != v1.length)
throw new MismatchedSizeException(VecMathI18N.getString("GVector1"));
for(i=0;i<length;i++) {
values[i] = v1.values[i]*s;
}
}
/**
* Scales this vector by the scale factor s.
* @param s the scalar value
*/
public final void scale(double s)
{
int i;
for(i=0;i<length;i++) {
values[i] = values[i]*s;
}
}
/**
* Sets the value of this vector to the scalar multiplication by s
* of vector v1 plus vector v2 (this = s*v1 + v2).
* @param s the scalar value
* @param v1 the vector to be multiplied
* @param v2 the vector to be added
*/
public final void scaleAdd(double s, GVector v1, GVector v2)
{
int i;
if( v2.length != v1.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector2"));
if( length != v1.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector3"));
for(i=0;i<length;i++) {
values[i] = v1.values[i]*s + v2.values[i];
}
}
/**
* Sets the value of this vector to sum of itself and the specified
* vector
* @param vector the second vector
*/
public final void add(GVector vector)
{
int i;
if( length != vector.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector4"));
for(i = 0; i < length; i++) {
this.values[i] += vector.values[i];
}
}
/**
* Sets the value of this vector to the vector sum of vectors vector1
* and vector2.
* @param vector1 the first vector
* @param vector2 the second vector
*/
public final void add(GVector vector1, GVector vector2)
{
int i;
if( vector1.length != vector2.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector5"));
if( length != vector1.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector6"));
for(i = 0; i < length; i++)
this.values[i] = vector1.values[i] + vector2.values[i];
}
/**
* Sets the value of this vector to the vector difference of itself
* and vector (this = this - vector).
* @param vector the other vector
*/
public final void sub(GVector vector)
{
int i;
if( length != vector.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector7"));
for(i = 0; i < length; i++) {
this.values[i] -= vector.values[i];
}
}
/**
* Sets the value of this vector to the vector difference
* of vectors vector1 and vector2 (this = vector1 - vector2).
* @param vector1 the first vector
* @param vector2 the second vector
*/
public final void sub(GVector vector1, GVector vector2)
{
int i,l;
if( vector1.length != vector2.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector8"));
if( length != vector1.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector9"));
for(i = 0; i < length; i++)
this.values[i] = vector1.values[i] - vector2.values[i];
}
/**
* Multiplies matrix m1 times Vector v1 and places the result
* into this vector (this = m1*v1).
* @param m1 The matrix in the multiplication
* @param v1 The vector that is multiplied
*/
public final void mul(GMatrix m1, GVector v1) {
if (m1.getNumCol() != v1.length)
throw new MismatchedSizeException(VecMathI18N.getString("GVector10"));
if (length != m1.getNumRow())
throw new MismatchedSizeException(VecMathI18N.getString("GVector11"));
double v[];
if (v1 != this) {
v = v1.values;
} else {
v = (double []) values.clone();
}
for(int j=length-1; j>=0; j--){
values[j] = 0.0;
for(int i=v1.length-1;i>=0; i--){
values[j] += m1.values[j][i] * v[i];
}
}
}
/**
* Multiplies the transpose of vector v1 (ie, v1 becomes a row
* vector with respect to the multiplication) times matrix m1
* and places the result into this vector
* (this = transpose(v1)*m1). The result is technically a
* row vector, but the GVector class only knows about column
* vectors, and so the result is stored as a column vector.
* @param m1 The matrix in the multiplication
* @param v1 The vector that is temporarily transposed
*/
public final void mul(GVector v1, GMatrix m1) {
if (m1.getNumRow() != v1.length)
throw new MismatchedSizeException(VecMathI18N.getString("GVector12"));
if (length != m1.getNumCol())
throw new MismatchedSizeException(VecMathI18N.getString("GVector13"));
double v[];
if (v1 != this) {
v = v1.values;
} else {
v = (double []) values.clone();
}
for (int j=length-1; j>=0; j--){
values[j] = 0.0;
for(int i=v1.length-1; i>=0; i--){
values[j] += m1.values[i][j] * v[i];
}
}
}
/**
* Negates the value of this vector: this = -this.
*/
public final void negate() {
for(int i=length-1; i>=0; i--) {
this.values[i] *= -1.0;
}
}
/**
* Sets all the values in this vector to zero.
*/
public final void zero() {
for (int i=0; i < this.length; i++) {
this.values[i] = 0.0;
}
}
/**
* Changes the size of this vector dynamically. If the size is increased
* no data values will be lost. If the size is decreased, only those data
* values whose vector positions were eliminated will be lost.
* @param length number of desired elements in this vector
*/
public final void setSize(int length) {
double[] tmp = new double[length];
int i,max;
if( this.length < length)
max = this.length;
else
max = length;
for(i=0;i<max;i++) {
tmp[i] = values[i];
}
this.length = length;
values = tmp;
}
/**
* Sets the value of this vector to the values found in the array
* parameter. The array should be at least equal in length to
* the number of elements in the vector.
* @param vector the source array
*/
public final void set(double[] vector) {
for(int i = length-1; i >=0; i--)
values[i] = vector[i];
}
/**
* Sets the value of this vector to the values found in vector vector.
* @param vector the source vector
*/
public final void set(GVector vector) {
int i;
if (length < vector.length) {
length = vector.length;
values = new double[length];
for(i = 0; i < length; i++)
values[i] = vector.values[i];
}else {
for(i = 0; i < vector.length; i++)
values[i] = vector.values[i];
for(i = vector.length; i < length; i++)
values[i] = 0.0;
}
}
/**
* Sets the value of this vector to the values in tuple
* @param tuple the source for the new GVector's new values
*/
public final void set(Tuple2f tuple)
{
if (length < 2) {
length = 2;
values = new double[2];
}
values[0] = (double)tuple.x;
values[1] = (double)tuple.y;
for(int i = 2; i < length; i++) values[i] = 0.0;
}
/**
* Sets the value of this vector to the values in tuple
* @param tuple the source for the new GVector's new values
*/
public final void set(Tuple3f tuple)
{
if (length < 3) {
length = 3;
values = new double[3];
}
values[0] = (double)tuple.x;
values[1] = (double)tuple.y;
values[2] = (double)tuple.z;
for(int i = 3; i < length; i++) values[i] = 0.0;
}
/**
* Sets the value of this vector to the values in tuple
* @param tuple the source for the new GVector's new values
*/
public final void set(Tuple3d tuple)
{
if (length < 3) {
length = 3;
values = new double[3];
}
values[0] = tuple.x;
values[1] = tuple.y;
values[2] = tuple.z;
for(int i = 3; i < length; i++) values[i] = 0.0;
}
/**
* Sets the value of this vector to the values in tuple
* @param tuple the source for the new GVector's new values
*/
public final void set(Tuple4f tuple)
{
if (length < 4) {
length = 4;
values = new double[4];
}
values[0] = (double)tuple.x;
values[1] = (double)tuple.y;
values[2] = (double)tuple.z;
values[3] = (double)tuple.w;
for(int i = 4; i < length; i++) values[i] = 0.0;
}
/**
* Sets the value of this vector to the values in tuple
* @param tuple the source for the new GVector's new values
*/
public final void set(Tuple4d tuple)
{
if (length < 4) {
length = 4;
values = new double[4];
}
values[0] = tuple.x;
values[1] = tuple.y;
values[2] = tuple.z;
values[3] = tuple.w;
for(int i = 4; i < length; i++) values[i] = 0.0;
}
/**
* Returns the number of elements in this vector.
* @return number of elements in this vector
*/
public final int getSize()
{
return values.length;
}
/**
* Retrieves the value at the specified index value of this vector.
* @param index the index of the element to retrieve (zero indexed)
* @return the value at the indexed element
*/
public final double getElement(int index)
{
return values[index];
}
/**
* Modifies the value at the specified index of this vector.
* @param index the index if the element to modify (zero indexed)
* @param value the new vector element value
*/
public final void setElement(int index, double value)
{
values[index] = value;
}
/**
* Returns a string that contains the values of this GVector.
* @return the String representation
*/
public String toString() {
StringBuffer buffer = new StringBuffer(length*8);
int i;
for(i=0;i<length;i++) {
buffer.append(values[i]).append(" ");
}
return buffer.toString();
}
/**
* Returns a hash code value based on the data values in this
* object. Two different GVector objects with identical data
* values (i.e., GVector.equals returns true) will return the
* same hash number. Two GVector objects with different data
* members may return the same hash value, although this is not
* likely.
* @return the integer hash code value
*/
public int hashCode() {
long bits = 1L;
for (int i = 0; i < length; i++) {
bits = 31L * bits + VecMathUtil.doubleToLongBits(values[i]);
}
return (int) (bits ^ (bits >> 32));
}
/**
* Returns true if all of the data members of GVector vector1 are
* equal to the corresponding data members in this GVector.
* @param vector1 The vector with which the comparison is made.
* @return true or false
*/
public boolean equals(GVector vector1)
{
try {
if( length != vector1.length) return false;
for(int i = 0;i<length;i++) {
if( values[i] != vector1.values[i]) return false;
}
return true;
}
catch (NullPointerException e2) { return false; }
}
/**
* Returns true if the Object o1 is of type GMatrix and all of the
* data members of o1 are equal to the corresponding data members in
* this GMatrix.
* @param o1 The object with which the comparison is made.
* @return true or false
*/
public boolean equals(Object o1)
{
try {
GVector v2 = (GVector) o1;
if( length != v2.length) return false;
for(int i = 0;i<length;i++) {
if( values[i] != v2.values[i]) return false;
}
return true;
}
catch (ClassCastException e1) { return false; }
catch (NullPointerException e2) { return false; }
}
/**
* Returns true if the L-infinite distance between this vector
* and vector v1 is less than or equal to the epsilon parameter,
* otherwise returns false. The L-infinite
* distance is equal to
* MAX[abs(x1-x2), abs(y1-y2), . . . ].
* @param v1 The vector to be compared to this vector
* @param epsilon the threshold value
*/
public boolean epsilonEquals(GVector v1, double epsilon)
{
double diff;
if( length != v1.length) return false;
for(int i = 0;i<length;i++) {
diff = values[i] - v1.values[i];
if( (diff<0?-diff:diff) > epsilon) return false;
}
return true;
}
/**
* Returns the dot product of this vector and vector v1.
* @param v1 the other vector
* @return the dot product of this and v1
*/
public final double dot(GVector v1)
{
if( length != v1.length)
throw new MismatchedSizeException(VecMathI18N.getString("GVector14"));
double result = 0.0;
for(int i = 0;i<length;i++) {
result += values[i] * v1.values[i];
}
return result;
}
/**
* Solves for x in Ax = b, where x is this vector (nx1), A is mxn,
* b is mx1, and A = U*W*transpose(V); U,W,V must
* be precomputed and can be found by taking the singular value
* decomposition (SVD) of A using the method SVD found in the
* GMatrix class.
* @param U The U matrix produced by the GMatrix method SVD
* @param W The W matrix produced by the GMatrix method SVD
* @param V The V matrix produced by the GMatrix method SVD
* @param b The b vector in the linear equation Ax = b
*/
public final void SVDBackSolve(GMatrix U, GMatrix W, GMatrix V, GVector b)
{
if( !(U.nRow == b.getSize() &&
U.nRow == U.nCol &&
U.nRow == W.nRow ) ) {
throw new MismatchedSizeException(VecMathI18N.getString("GVector15"));
}
if( !(W.nCol == values.length &&
W.nCol == V.nCol &&
W.nCol == V.nRow ) ) {
throw new MismatchedSizeException(VecMathI18N.getString("GVector23"));
}
GMatrix tmp = new GMatrix( U.nRow, W.nCol);
tmp.mul( U, V);
tmp.mulTransposeRight( U, W);
tmp.invert();
mul(tmp, b);
}
/**
* LU Decomposition Back Solve; this method takes the LU matrix
* and the permutation vector produced by the GMatrix method LUD
* and solves the equation (LU)*x = b by placing the solution vector
* x into this vector. This vector should be the same length or
* longer than b.
* @param LU The matrix into which the lower and upper decompostions
* have been placed
* @param b The b vector in the equation (LU)*x = b
* @param permutation The row permuations that were necessary to
* produce the LU matrix parameter
*/
public final void LUDBackSolve(GMatrix LU, GVector b, GVector permutation)
{
int size = LU.nRow*LU.nCol;
double[] temp = new double[size];
double[] result = new double[size];
int[] row_perm = new int[b.getSize()];
int i,j;
if( LU.nRow != b.getSize() ) {
throw new MismatchedSizeException(VecMathI18N.getString("GVector16"));
}
if( LU.nRow != permutation.getSize() ) {
throw new MismatchedSizeException(VecMathI18N.getString("GVector24"));
}
if (LU.nRow != LU.nCol) {
throw new MismatchedSizeException(VecMathI18N.getString("GVector25"));
}
for(i=0;i<LU.nRow;i++) {
for(j=0;j<LU.nCol;j++) {
temp[i*LU.nCol+j] = LU.values[i][j];
}
}
for(i=0;i<size;i++) result[i] = 0.0;
for(i=0;i<LU.nRow;i++) result[i*LU.nCol] = b.values[i];
for(i=0;i<LU.nCol;i++) row_perm[i] = (int)permutation.values[i];
GMatrix.luBacksubstitution(LU.nRow, temp, row_perm, result);
for(i=0;i<LU.nRow;i++) this.values[i] = result[i*LU.nCol];
}
/**
* Returns the (n-space) angle in radians between this vector and
* the vector parameter; the return value is constrained to the
* range [0,PI].
* @param v1 The other vector
* @return The angle in radians in the range [0,PI]
*/
public final double angle(GVector v1)
{
return( Math.acos( this.dot(v1) / ( this.norm()*v1.norm() ) ) );
}
/**
* @deprecated Use interpolate(GVector, GVector, double) instead
*/
public final void interpolate(GVector v1, GVector v2, float alpha) {
interpolate(v1, v2, (double)alpha);
}
/**
* @deprecated Use interpolate(GVector, double) instead
*/
public final void interpolate(GVector v1, float alpha) {
interpolate(v1, (double)alpha);
}
/**
* Linearly interpolates between vectors v1 and v2 and places the
* result into this tuple: this = (1-alpha)*v1 + alpha*v2.
* @param v1 the first vector
* @param v2 the second vector
* @param alpha the alpha interpolation parameter
*/
public final void interpolate(GVector v1, GVector v2, double alpha)
{
if( v2.length != v1.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector20"));
if( length != v1.length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector21"));
for(int i=0;i<length;i++) {
values[i] = (1-alpha)*v1.values[i] + alpha*v2.values[i];
}
}
/**
* Linearly interpolates between this vector and vector v1 and
* places the result into this tuple: this = (1-alpha)*this + alpha*v1.
* @param v1 the first vector
* @param alpha the alpha interpolation parameter
*/
public final void interpolate(GVector v1, double alpha)
{
if( v1.length != length )
throw new MismatchedSizeException(VecMathI18N.getString("GVector22"));
for(int i=0;i<length;i++) {
values[i] = (1-alpha)*values[i] + alpha*v1.values[i];
}
}
/**
* Creates a new object of the same class as this object.
*
* @return a clone of this instance.
* @exception OutOfMemoryError if there is not enough memory.
* @see java.lang.Cloneable
* @since vecmath 1.3
*/
public Object clone() {
GVector v1 = null;
try {
v1 = (GVector)super.clone();
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
// Also need to clone array of values
v1.values = new double[length];
for (int i = 0; i < length; i++) {
v1.values[i] = values[i];
}
return v1;
}
}