Merge pull request #66 from keatis/main

Fixed median() to handle unsorted data. Minor text changes for consistency

src/Stat.php

@@ -56,6 +56,7 @@ public static function mean(array $data): int|float|null
      */
     public static function median(array $data, string $medianType = self::MEDIAN_TYPE_MIDDLE): mixed
     {
+        sort($data);
         $count = self::count($data);
         if ($count === 0) {
             throw new InvalidDataInputException('The data must not be empty.');
@@ -170,7 +171,7 @@ public static function multimode(array $data): array|null
      */
     public static function quantiles(array $data, int $n = 4, ?int $round = null): array
     {
-        $count = Stat::count($data);
+        $count = self::count($data);
         if ($count < 2 || $n < 1) {
             throw new InvalidDataInputException(
                 'The size of the data must be greater than 2 and the number of quantiles must be greater than 1.'

tests/StatTest.php

@@ -3,7 +3,7 @@
 use HiFolks\Statistics\Exception\InvalidDataInputException;
 use HiFolks\Statistics\Stat;
 
-it('can calculate mean (static)', function () {
+it('calculates mean (static)', function () {
     expect(
         Stat::mean([1, 2, 3, 4, 4])
     )->toEqual(2.8);
@@ -15,35 +15,47 @@
     )->toThrow(InvalidDataInputException::class);
 });
 
-it('can calculate median (static)', function () {
+it('calculates median (static)', function () {
     expect(
         Stat::median([1, 3, 5])
     )->toEqual(3);
     expect(
         Stat::median([1, 3, 5, 7])
     )->toEqual(4);
+    expect(
+        Stat::median([1001, 999, 998, 1001, 1002])
+    )->toEqual(1001);
+    expect(
+        Stat::median([1001, 999, 998, 1003, 1002, 1003])
+    )->toEqual(1001.5);
     expect(
         fn() => Stat::median([])
     )->toThrow(InvalidDataInputException::class);
 });
-it('can calculate median low (static)', function () {
+it('calculates median low (static)', function () {
     expect(
         Stat::medianLow([1, 3, 5])
     )->toEqual(3);
     expect(
         Stat::medianLow([1, 3, 5, 7])
     )->toEqual(3);
+    expect(
+        Stat::medianLow([1001, 999, 998, 1003, 1002, 1003])
+    )->toEqual(1001);
     expect(
         fn() => Stat::medianLow([])
     )->toThrow(InvalidDataInputException::class);
 });
-it('can calculate median high (static)', function () {
+it('calculates median high (static)', function () {
     expect(
         Stat::medianHigh([1, 3, 5])
     )->toEqual(3);
     expect(
         Stat::medianHigh([1, 3, 5, 7])
     )->toEqual(5);
+    expect(
+        Stat::medianHigh([1001, 999, 998, 1003, 1002, 1003])
+    )->toEqual(1002);
     expect(
         fn() => Stat::medianHigh([])
     )->toThrow(InvalidDataInputException::class);