Added constants file

Author: andrewdalpino

composer.json

@@ -28,7 +28,10 @@
         "psr-4": {
             "Rubix\\Tensor\\": "src/",
             "JAMA\\": "lib/JAMA"
-        }
+        },
+        "files": [
+            "src/Constants.php"
+        ]
     },
     "autoload-dev": {
         "psr-4": {

src/Constants.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Rubix\Tensor
+{
+    /**
+     * A small number used in substitution of 0.
+     */
+    const EPSILON = 1e-8;
+
+    /**
+     * Two multiplied by pi.
+     */
+    const TWO_PI = 2. * M_PI;
+}

src/Matrix.php

@@ -10,6 +10,9 @@
 use Exception;
 use Closure;
 
+use const Rubix\Tensor\EPSILON;
+use const Rubix\Tensor\TWO_PI;
+
 /**
  * Matrix
  *
@@ -262,8 +265,8 @@ public static function gaussian(int $m, int $n) : self
 
                 $r = sqrt(-2. * log($r1));
 
-                $row[] = $r * sin($r2 * self::TWO_PI);
-                $row[] = $r * cos($r2 * self::TWO_PI);
+                $row[] = $r * sin($r2 * TWO_PI);
+                $row[] = $r * cos($r2 * TWO_PI);
             }
 
             if (count($row) > $n) {
@@ -1134,7 +1137,7 @@ public function lu() : array
                 }
 
                 $l[$j][$i] = ($pa[$j][$i] - $sigma)
-                    / ($u[$i][$i] ?: self::EPSILON);
+                    / ($u[$i][$i] ?: EPSILON);
             }
         }
 
@@ -1166,8 +1169,7 @@ public function eig(bool $normalize = true) : array
         $eigenvalues = $decomp->getRealEigenvalues();
         $eigenvectors = $decomp->getV()->getArray();
 
-        $eigenvectors = self::quick($eigenvectors)
-            ->transpose();
+        $eigenvectors = self::quick($eigenvectors)->transpose();
 
         if ($normalize === true) {
             $norm = $eigenvectors->transpose()
@@ -1198,7 +1200,7 @@ public function solve(Vector $b) : ColumnVector
 
         $pb = $p->dot($b);
 
-        $y = [$pb[0] / ($l[0][0] ?: self::EPSILON)];
+        $y = [$pb[0] / ($l[0][0] ?: EPSILON)];
 
         for ($i = 1; $i < $this->m; $i++) {
             $sigma = 0;
@@ -1212,7 +1214,7 @@ public function solve(Vector $b) : ColumnVector
 
         $x = [];
 
-        $x = [$k => $y[$k] / ($l[$k][$k] ?: self::EPSILON)];
+        $x = [$k => $y[$k] / ($l[$k][$k] ?: EPSILON)];
 
         for ($i = $this->m - 2; $i >= 0; $i--) {
             $sigma = 0;
@@ -3888,7 +3890,7 @@ public function offsetUnset($index) : void
      */
     public function offsetGet($index) : array
     {
-        if (!isset($this->a[$index])) {
+        if (empty($this->a[$index])) {
             throw new InvalidArgumentException('Element not found at'
                 . " offset $index.");
         }

src/Tensor.php

@@ -8,10 +8,6 @@
 
 interface Tensor extends ArrayAccess, IteratorAggregate, Countable
 {
-    const TWO_PI = 2. * M_PI;
-
-    const EPSILON = 1e-8;
-
     /**
      * Return a tuple with the dimensionality of the tensor.
      *

src/Vector.php

@@ -9,6 +9,9 @@
 use Exception;
 use Closure;
 
+use const Rubix\Tensor\EPSILON;
+use const Rubix\Tensor\TWO_PI;
+
 /**
  * Vector
  *
@@ -160,8 +163,8 @@ public static function gaussian(int $n) : self
 
             $r = sqrt(-2. * log($r1));
 
-            $a[] = $r * sin($r2 * self::TWO_PI);
-            $a[] = $r * cos($r2 * self::TWO_PI);
+            $a[] = $r * sin($r2 * TWO_PI);
+            $a[] = $r * cos($r2 * TWO_PI);
         }
 
         if (count($a) > $n) {
@@ -231,7 +234,7 @@ public static function linspace(float $start, float $end, int $n) : self
 
         $range = abs($end - $start);
 
-        $interval = ($range / ($n - 1)) - (self::EPSILON * $range);
+        $interval = ($range / ($n - 1)) - (EPSILON * $range);
 
         return static::range($start, $end, $interval);
     }