fix variable init

1 files changed, 3 insertions, 1 deletions

diff --git a/tests/Unit/Entropy/EntropyTest.php b/tests/Unit/Entropy/EntropyTest.php
index 0b3266f..c4f515d 100644
--- a/tests/Unit/Entropy/EntropyTest.php
+++ b/tests/Unit/Entropy/EntropyTest.php
@@ -77,7 +77,9 @@ class EntropyTest extends TestCase
     public function testSd($data, $sd)
     {
         $this->assertEquals(number_format($this->invokePrivate($this->entropy, 'sd', [$data]), 6), $sd);
-        $sum = 0.0, $mean = 0.0, $standardDeviation = 0.0;
+        $sum = 0.0;
+        $mean = 0.0;
+        $standardDeviation = 0.0;
         foreach($data as $key => $value) {
             $sum = $sum + pow($value, 2);
             $mean = $this->invokePrivate($this->entropy, 'streamMean', [$mean, $value, $key + 1]);