Initial commit

polynomial/math.php

@@ -0,0 +1,91 @@
+<?php
+require_once('regression.php');
+/* function zc_math_autoloader($class) {
+	require_once($class . ".php");
+}
+
+spl_autoload_register('zc_math_autoloader'); */
+
+/**
+ * Math class
+ *
+ * Math helper functions
+ * -- INDEX --
+ * matrix_multiply
+ * matrix_transpose
+ *
+ * @author Han Lin Yap < http://zencodez.net/ >
+ * @copyright 2010 zencodez.net
+ * @license http://creativecommons.org/licenses/by-sa/3.0/
+ * @package math
+ * @version 1.0 - 2010-08-13
+ */
+class zc_math {
+	/**
+	 * Factory
+	 * @param string $classname optional math class to initialize
+	 * @param mixed $args optional arguments of the class constructor
+	 * @return instance of math class
+	 * @since 1.0
+	 */
+	public static function factory() {
+		$args = func_get_args();
+		$class = array_shift($args);
+		$reflection = new ReflectionClass(__CLASS__ . '_' . $class);
+		return $reflection->newInstanceArgs($args);
+	}
+
+	/**
+	 * Matrix multiplication
+	 * @link http://en.wikipedia.org/wiki/Matrix_multiplication Wikipedia
+	 * @param matrix $left Left matrix
+	 * @param matrix $right Right matrix
+	 * @return matrix
+	 * @since 1.0
+	 */
+	public static function matrix_multiply($left, $right) {
+		$m = array_fill(0, count($left), array());
+
+		foreach ($right[0] as $r_col => $v) {
+			foreach ($left as $l_row => $l_col) {
+				$z = 0;
+				foreach ($l_col as $col => $l_value) {
+					$z += $l_value * $right[$col][$r_col];
+				}
+				$m[$l_row][$r_col] = $z;
+			}
+		}
+		
+		return $m;
+	}
+	/**
+	 * Matrix transpose
+	 *
+	 * Eg.
+	 * [1,2,3]
+	 * [4,5,6]
+	 * becomes
+	 * [1,4]
+	 * [2,5]
+	 * [3,6]
+	 * @link http://en.wikipedia.org/wiki/Transpose Wikipedia
+	 * @link http://stackoverflow.com/questions/797251/transposing-multidimensional-arrays-in-php/797268#797268
+	 * @param matrix $transpose matrix to transpose
+	 * @return matrix Transposed matrix
+	 * @since 1.0
+	 */
+	public static function matrix_transpose($transpose) {
+		/* array_unshift($transpose, null);
+		return call_user_func_array('array_map', $transpose); */
+	
+		$out = array();
+		foreach ($transpose as $key => $subarr) {
+			foreach ($subarr as $subkey => $subvalue) {
+					$out[$subkey][$key] = $subvalue;
+			}
+		}
+		return $out;
+	}
+}
+
+?>