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<?php
//
// +----------------------------------------------------------------------+
// | PHP Version 4 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Jesus M. Castagnetto <jmcastagnetto@php.net> |
// +----------------------------------------------------------------------+
//
// $Id: VectorOp.php 304045 2010-10-05 00:16:53Z clockwerx $
//
/**
* Vector operation class.
* A static class implementing methods to operate on Vector objects.
* Originally this class was part of NumPHP (Numeric PHP package)
*
* @author Jesus M. Castagnetto <jmcastagnetto@php.net>
* @version 1.0
* @access public
* @package Math_Vector
*/
class Math_VectorOp {
/**
* Checks if object is of Math_Vector class (or a subclass of Math_Vector)
*
* @access public
* @param object $obj
* @return boolean true on success
*/
function isVector($obj) /*{{{*/
{
if (function_exists("is_a"))
return (is_object($obj) && is_a($obj, "Math_Vector"));
else
return (is_object($obj) && (strtolower(get_class($obj)) == "math_vector" ||
is_subclass_of($obj, "Math_Vector")));
}/*}}}*/
/**
* Checks if object is of Math_Vector2 class (or a subclass of Math_Vector2)
*
* @access public
* @param object $obj
* @return boolean true on success
*/
function isVector2($obj) /*{{{*/
{
if (function_exists("is_a"))
return (is_object($obj) && is_a($obj, "Math_Vector2"));
else
return (is_object($obj) && (strtolower(get_class($obj)) == "math_vector2" ||
is_subclass_of($obj, "Math_Vector2")));
}/*}}}*/
/**
* Checks if object is of Math_Vector3 class (or a subclass of Math_Vector3)
*
* @access public
* @param object $obj
* @return boolean true on success
*/
function isVector3($obj) /*{{{*/
{
if (function_exists("is_a"))
return (is_object($obj) && is_a($obj, "Math_Vector3"));
else
return (is_object($obj) && (strtolower(get_class($obj)) == "math_vector3" ||
is_subclass_of($obj, "Math_Vector3")) );
}/*}}}*/
/**
* Creates a vector of a given size in which all elements have the same value
*
* @access public
* @param int $size vector size
* @param numeric $value value to assign to the elements
* @return object if ($size == 2) Math_Vector2 elseif ($size == 3) Math_Vector3 else Math_Vector
*/
function create ($size, $value) /*{{{*/
{
if ($size == 2)
$VClass = "Math_Vector2";
elseif ($size == 3)
$VClass = "Math_Vector3";
else
$VClass = "Math_Vector";
return new $VClass(Math_VectorOp::_fill(0, $size, $value));
}/*}}}*/
/**
* Creates a zero-filled vector of the given size
*
* @access public
* @param int $size vector size
* @return object if ($size == 2) Math_Vector2 elseif ($size == 3) Math_Vector3 else Math_Vector
*
* @see create()
*/
function createZero ($size)
{
return Math_VectorOp::create ($size, 0);
}
/**
* Creates a one-filled vector of the given size
*
* @access public
* @param int $size vector size
* @return object if ($size == 2) Math_Vector2 elseif ($size == 3) Math_Vector3 else Math_Vector
*
* @see create()
*/
function createOne ($size) /*{{{*/
{
return Math_VectorOp::create ($size, 1);
}/*}}}*/
/**
* Creates a basis vector of the given size
* A basis vector of size n, has n - 1 elements equal to 0
* and one element equal to 1
*
* @access public
* @param int $size vector size
* @param int $index element to be set at 1
* @return object if ($size == 2) Math_Vector2 elseif ($size == 3) Math_Vector3 else Math_Vector, on error PEAR_Error
*
* @see createZero()
*/
function createBasis ($size, $index) /*{{{*/
{
if ($index >= $size)
return PEAR::raiseError("Incorrect index for size: $index >= $size");
$v = Math_VectorOp::createZero($size);
$res =$v->set($index, 1);
if (PEAR::isError($res))
return $res;
else
return $v;
}/*}}}*/
/**
* Vector addition
* v + w = <v1 + w1, v2 + w2, ..., vk + wk>
*
* @access public
* @param object Math_Vector (or subclass) $v1
* @param object Math_Vector (or subclass) $v2
* @return object Math_Vector (or subclass) on success, PEAR_Error otherwise
*
* @see isVector()
*/
function add ($v1, $v2) /*{{{*/
{
if (Math_VectorOp::isVector($v1) && Math_VectorOp::isVector($v2)) {
$n = $v1->size();
if ($v2->size() != $n)
return PEAR::raiseError("Vectors must of the same size");
for ($i=0; $i < $n; $i++)
$arr[$i] = $v1->get($i) + $v2->get($i);
return new Math_Vector($arr);
} else {
return PEAR::raiseError("V1 and V2 must be Math_Vector objects");
}
}/*}}}*/
/**
* Vector substraction
* v - w = <v1 - w1, v2 - w2, ..., vk - wk>
*
* @access public
* @param object Math_Vector (or subclass) $v1
* @param object Math_Vector (or subclass) $v2
* @return object Math_Vector (or subclass) on success, PEAR_Error otherwise
*
* @see isVector()
*/
function substract ($v1, $v2) /*{{{*/
{
if (Math_VectorOp::isVector($v1) && Math_VectorOp::isVector($v2)) {
$n = $v1->size();
if ($v2->size() != $n)
return PEAR::raiseError("Vectors must of the same size");
for ($i=0; $i < $n; $i++)
$arr[$i] = $v1->get($i) - $v2->get($i);
return new Math_Vector($arr);
} else {
return PEAR::raiseError("V1 and V2 must be Math_Vector objects");
}
}/*}}}*/
/**
* Vector multiplication
* v * w = <v1 * w1, v2 * w2, ..., vk * wk>
*
* @access public
* @param object Math_Vector (or subclass) $v1
* @param object Math_Vector (or subclass) $v2
* @return object Math_Vector (or subclass) on success, PEAR_Error otherwise
*
* @see isVector()
*/
function multiply ($v1, $v2) /*{{{*/
{
if (Math_VectorOp::isVector($v1) && Math_VectorOp::isVector($v2)) {
$n = $v1->size();
if ($v2->size() != $n)
return PEAR::raiseError("Vectors must of the same size");
for ($i=0; $i < $n; $i++)
$arr[$i] = $v1->get($i) * $v2->get($i);
return new Math_Vector($arr);
} else {
return PEAR::raiseError("V1 and V2 must be Math_Vector objects");
}
}/*}}}*/
/**
* Vector scaling
* f * w = <f * w1, f * w2, ..., f * wk>
*
* @access public
* @param numeric $f scaling factor
* @param object Math_Vector (or subclass) $v
* @return object Math_Vector (or subclass) on success, PEAR_Error otherwise
*
* @see isVector()
*/
function scale ($f, $v) /*{{{*/
{
if (is_numeric($f) && Math_VectorOp::isVector($v)) {
$n = $v->size();
for ($i=0; $i < $n; $i++)
$arr[$i] = $v->get($i) * $f;
return new Math_Vector($arr);
} else {
return PEAR::raiseError("Requires a numeric factor and a Math_Vector object");
}
}/*}}}*/
/**
* Vector division
* v / w = <v1 / w1, v2 / w2, ..., vk / wk>
*
* @access public
* @param object Math_Vector (or subclass) $v1
* @param object Math_Vector (or subclass) $v2
* @return object Math_Vector (or subclass) on success, PEAR_Error otherwise
*
* @see isVector()
*/
function divide ($v1, $v2) /*{{{*/
{
if (Math_VectorOp::isVector($v1) && Math_VectorOp::isVector($v2)) {
$n = $v1->size();
if ($v2->size() != $n)
return PEAR::raiseError("Vectors must of the same size");
for ($i=0; $i < $n; $i++) {
$d = $v2->get($i);
if ($d == 0)
return PEAR::raiseError("Division by zero: Element $i in V2 is zero");
$arr[$i] = $v1->get($i) / $d;
}
return new Math_Vector($arr);
} else {
return PEAR::raiseError("V1 and V2 must be Math_Vector objects");
}
}/*}}}*/
/**
* Vector dot product = v . w = |v| |w| cos(theta)
*
* @access public
* @param object Math_Vector2 or MathVector3 (or subclass) $v1
* @param object Math_Vector2 or MathVector3 (or subclass) $v2
* @return mixed the dot product (float) on success, a PEAR_Error object otherwise
*
* @see isVector2()
* @see isVector3()
*/
function dotProduct ($v1, $v2)/*{{{*/
{
if (Math_VectorOp::isVector2($v1) && Math_VectorOp::isVector2($v2))
return ( $v1->getX() * $v2->getX() +
$v1->getY() * $v2->getY() );
elseif (Math_VectorOp::isVector3($v1) && Math_VectorOp::isVector3($v2))
return ( $v1->getX() * $v2->getX() +
$v1->getY() * $v2->getY() +
$v1->getZ() * $v2->getZ() );
else
return PEAR::raiseError("Vectors must be both of the same type");
}/*}}}*/
/**
* Vector cross product = v x w
*
* @access public
* @param object Math_Vector3 (or subclass) $v1
* @param object Math_Vector3 (or subclass) $v2
* @return object the cross product vector (Math_Vector3) on success, a PEAR_Error object otherwise
*
* @see isVector3()
*/
function crossProduct ($v1, $v2)
{
if (Math_VectorOp::isVector3($v1) && Math_VectorOp::isVector3($v2)) {
$arr[0] = $v1->getY() * $v2->getZ() - $v1->getZ() * $v2->getY();
$arr[1] = $v1->getZ() * $v2->getX() - $v1->getX() * $v2->getZ();
$arr[2] = $v1->getX() * $v2->getY() - $v1->getY() * $v2->getX();
return new Math_Vector3($arr);
} else {
return PEAR::raiseError("Vectors must be both of the same type");
}
}
/**
* Vector triple scalar product = v1 . (v2 x v3)
*
* @access public
* @param object Math_Vector3 (or subclass) $v1
* @param object Math_Vector3 (or subclass) $v2
* @param object Math_Vector3 (or subclass) $v3
* @return mixed the triple scalar product (float) on success, a PEAR_Error object otherwise
*
* @see isVector3()
* @see dotProduct()
* @see crossProduct()
*/
function tripleScalarProduct ($v1, $v2, $v3) /*{{{*/
{
if (Math_VectorOp::isVector3($v1)
&& Math_VectorOp::isVector3($v2)
&& Math_VectorOp::isVector3($v3))
return Math_VectorOp::dotProduct($v1,Math_VectorOp::crossProduct($v2, $v3));
else
return PEAR_Error("All three vectors must be of the same type");
}/*}}}*/
/**
* Angle between vectors, using the equation: v . w = |v| |w| cos(theta)
*
* @access public
* @param object Math_Vector2 or MathVector3 (or subclass) $v1
* @param object Math_Vector2 or MathVector3 (or subclass) $v2
* @return mixed the angle between vectors (float, in radians) on success, a PEAR_Error object otherwise
*
* @see isVector2()
* @see isVector3()
* @see dotProduct()
*/
function angleBetween($v1, $v2) /*{{{*/
{
if ( (Math_VectorOp::isVector2($v1) && Math_VectorOp::isVector2($v2)) ||
(Math_VectorOp::isVector3($v1) && Math_VectorOp::isVector3($v2)) ) {
$v1->normalize();
$v2->normalize();
return acos( Math_VectorOp::dotProduct($v1,$v2) );
} else {
return PEAR::raiseError("Vectors must be both of the same type");
}
}/*}}}*/
/**
* To generate an array of a given size filled with a single value
* If available uses array_fill()
*
* @access private
* @param int $index starting index
* @param int $size size of the array
* @param numeric $value value to use for filling the array
* @return array
*/
function _fill($index, $size, $value)/*{{{*/
{
if (function_exists("array_fill"))
return array_fill($index, $size, $value);
for ($i=$index; $i < ($index + $size); $i++)
$arr[$i] = $value;
return $arr;
}/*}}}*/
}
?>
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