Fix #29

Math/Number/Complex.php

@@ -148,7 +148,9 @@ class Complex
 
     public function pow($value) : Complex
     {
-        if (is_numeric($value)) {
+        if (is_int($value)) {
+            return $this->powInteger($value);
+        } elseif (is_numeric($value)) {
             return $this->powScalar($value);
         } elseif ($value instanceof Complex) {
             return $this->powComplex($value);
@@ -162,6 +164,28 @@ class Complex
 
     }
 
+    /**
+     * Power with integer
+     * 
+     * @param int $value Power
+     * 
+     * @return Complex
+     * 
+     * @since  1.0.0
+     */
+    public function powInteger(int $value) : Complex
+    {
+        if ($value === 0) {
+            return new self(1, 0);
+        } elseif ($value === 1) {
+            return $this;
+        }
+
+        for ($i = $value; $i > 0; --$i) {
+            return $this->multComplex($this->powInteger($i));
+        }
+    }
+
     public function powScalar() : Complex
     {
 

tests/Math/Number/ComplexTest.php

@@ -58,6 +58,9 @@ class ComplexTest extends \PHPUnit\Framework\TestCase
         self::assertEquals('0.16 - 0.12i', $cpl->reciprocal()->render(2));
 
         self::assertEquals('7.00 + 24.00i', $cpl->square()->render());
+        self::assertEquals('7.00 + 24.00i', $cpl->pow(2)->render());
+        self::assertEquals('-44.00 - 117.00i', $cpl->pow(3)->render());
+
         self::assertEquals(5, $cpl->abs(), '', 0.01);
 
         self::assertEquals('2.12 + 0.71i', $cpl->sqrt()->render());