From 2952557028dba99afac9c9dd5425b6665fb0634f Mon Sep 17 00:00:00 2001
From: Arkadiusz Kondas <arkadiusz.kondas@gmail.com>
Date: Sat, 30 Apr 2016 23:47:35 +0200
Subject: [PATCH] improve matrix inverse

---
 src/Phpml/Math/Matrix.php | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/Phpml/Math/Matrix.php b/src/Phpml/Math/Matrix.php
index aeab3bc..ee8fd3c 100644
--- a/src/Phpml/Math/Matrix.php
+++ b/src/Phpml/Math/Matrix.php
@@ -53,7 +53,7 @@ class Matrix
 
     /**
      * @param array $array
-     * 
+     *
      * @return Matrix
      */
     public static function fromFlatArray(array $array)
@@ -225,12 +225,8 @@ class Matrix
         $newMatrix = array();
         for ($i = 0; $i < $this->rows; ++$i) {
             for ($j = 0; $j < $this->columns; ++$j) {
-                $subMatrix = $this->crossOut($i, $j);
-                if (fmod($i + $j, 2) == 0) {
-                    $newMatrix[$i][$j] = ($subMatrix->getDeterminant());
-                } else {
-                    $newMatrix[$i][$j] = -($subMatrix->getDeterminant());
-                }
+                $minor = $this->crossOut($i, $j)->getDeterminant();
+                $newMatrix[$i][$j] = fmod($i + $j, 2) == 0 ? $minor : -$minor;
             }
         }