- Fixed matrices to use parameter order <row>, <column>

- Added dataset which builds polygon of defined order for set of points
  # Using least squares algorithm
- Added method to solve a subset of nonlinear equatations to matrix class
  # Using Gauss-Newton algorithm

1 files changed, 78 insertions, 1 deletions

diff --git a/src/datasets/average.php b/src/datasets/average.php
index 3af2094..a964f57 100644
--- a/src/datasets/average.php
+++ b/src/datasets/average.php
@@ -9,11 +9,88 @@
  */
 /**
  * Extension of basic dataset to represent averation.
+ * Algorithm: http://en.wikipedia.org/wiki/Least_squares
  *
  * @package Graph
  */
-class ezcGraphDataSetAverage extends ezcGraphDataSet 
+class ezcGraphDataSetAveragePolynom extends ezcGraphDataSet 
 {
+    protected $polynomOrder = 3;
 
+    protected $source;
+
+    protected $resolution = 5;
+
+    protected $polynom = false;
+
+    public function __construct( ezcGraphDataSet $dataset )
+    {
+        $this->source = $dataset;
+    }
+
+    /**
+     * Options write access
+     * 
+     * @throws ezcBasePropertyNotFoundException
+     *          If Option could not be found
+     * @throws ezcBaseValueException
+     *          If value is out of range
+     * @param mixed $propertyName   Option name
+     * @param mixed $propertyValue  Option value;
+     * @return mixed
+     */
+    public function __set( $propertyName, $propertyValue ) 
+    {
+        switch ( $propertyName ) {
+            case 'polynomOrder':
+                $this->polynomOrder = (int) $propertyValue;
+                $this->polynom = false;
+                break;
+            default:
+                throw new ezcBasePropertyNotFoundException( $propertyName );
+                break;
+        }
+    }
+    
+    protected function buildPolynom()
+    {
+        $points = array();
+
+        foreach ( $this->source as $key => $value )
+        {
+            $points[] = new ezcGraphCoordinate( (float) $key, (float) $value );
+        }
+
+        // Build transposed and normal Matrix out of coordiantes
+        $a = new ezcGraphMatrix( count( $points ), $this->polynomOrder + 1 );
+        $b = new ezcGraphMatrix( count( $points ), 1 );
+
+        for ( $i = 0; $i <= $this->polynomOrder; ++$i )
+        {
+            foreach ( $points as $nr => $point )
+            {
+                $a->set( $nr, $i, pow( $point->x, $i ) );
+                $b->set( $nr, 0, $point->y );
+            }
+        }
+
+        $at = clone $a;
+        $at->transpose();
+        
+        $left = $at->multiply( $a );
+        $right = $at->multiply( $b );
+
+        $this->polynom = $left->solveNonlinearEquatation( $right );
+    }
+
+    public function getPolynom()
+    {
+        if ( $this->polynom === false )
+        {
+            $this->buildPolynom();
+        }
+
+        return $this->polynom;
+    }
 }
 ?>