test fixes

Math/Geometry/ConvexHull/GrahamScan.php

@@ -45,16 +45,14 @@ final class GrahamScan
      */
     public static function createConvexHull(array $points) : array
     {
-        $count = \count($points);
+        if (($n = \count($points)) < 3) {
-
+            return $points;
-        if ($count < 3) {
-            return [];
         }
 
         $min    = 1;
         $points = \array_merge([null], $points);
 
-        for ($i = 2; $i < $count; ++$i) {
+        for ($i = 2; $i < $n; ++$i) {
             if ($points[$i]['y'] < $points[$min]['y']
                 || ($points[$i]['y'] === $points[$min]['y'] && $points[$i]['x'] < $points[$min]['x'])
             ) {
@@ -69,7 +67,7 @@ final class GrahamScan
         $c = $points[1];
 
         /** @var array<int, array{x:int|float, y:int|float}> $subpoints */
-        $subpoints = \array_slice($points, 2, $count);
+        $subpoints = \array_slice($points, 2, $n);
         \usort($subpoints, function (array $a, array $b) use ($c) : int {
             // @todo: Might be wrong order of comparison
             return \atan2($a['y'] - $c['y'], $a['x'] - $c['x']) <=> \atan2($b['y'] - $c['y'],  $b['x'] - $c['x']);
@@ -77,14 +75,14 @@ final class GrahamScan
 
         /** @var array<int, array{x:int|float, y:int|float}> $points */
         $points    = \array_merge([$points[0], $points[1]], $subpoints);
-        $points[0] = $points[$count];
+        $points[0] = $points[$n];
 
         $size = 1;
-        for ($i = 2; $i <= $count; ++$i) {
+        for ($i = 2; $i <= $n; ++$i) {
             while (self::ccw($points[$size - 1], $points[$size], $points[$i]) <= 0) {
                 if ($size > 1) {
                     --$size;
-                } elseif ($i === $count) {
+                } elseif ($i === $n) {
                     break;
                 } else {
                     ++$i;

Math/Geometry/ConvexHull/MonotoneChain.php

@@ -45,7 +45,7 @@ final class MonotoneChain
      */
     public static function createConvexHull(array $points) : array
     {
-        if (($n = \count($points)) < 2) {
+        if (($n = \count($points)) < 3) {
             return $points;
         }
 

Math/Matrix/Matrix.php

@@ -772,14 +772,14 @@ class Matrix implements \ArrayAccess, \Iterator
                 }
             }
 
-            return self::fromArray($sum);
+            return Vector::fromArray($sum);
         } elseif ($axis === 1) {
             $sum = [];
             foreach ($this->matrix as $idx => $row) {
                 $sum[$idx] = \array_sum($row);
             }
 
-            return self::fromArray($sum);
+            return Vector::fromArray($sum);
         }
 
         return new self();