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Added statistics utility class
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‎CHANGELOG.md

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### 11.1.0 <small>(2025-??-??)</small>
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#### New
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* Added a statistics utility class with the following methods:
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- `Statistics::mean()`
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- `Statistics::median()`
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- `Statistics::mode()`
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- `Statistics::midrange()`
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- `Statistics::sampleVariance()`
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- `Statistics::populationVariance()`
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#### Changes
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* Command argument aliases are now shown in a separate column.
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### 11.0.0 <small>(2025-01-03)</small>
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The major version bump is due to upping the required PHP version from `8.1` to `8.4` and a several breaking changes. Most applications built using Mako `10` should run on Mako `11` with just a few simple adjustments.

‎src/mako/utility/Statistics.php

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<?php
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/**
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* @copyright Frederic G. Østby
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* @license http://www.makoframework.com/license
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*/
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namespace mako\utility;
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use mako\utility\exceptions\StatisticsException;
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use function array_count_values;
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use function array_keys;
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use function array_sum;
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use function count;
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use function max;
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use function min;
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use function sort;
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/**
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* Class containing statistic helper methods.
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*/
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class Statistics
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{
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/**
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* Returns the mean of the numbers in the array.
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*/
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public static function mean(array $numbers): float|int
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{
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$count = count($numbers);
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if ($count === 0) {
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throw new StatisticsException('The array can not be empty.');
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}
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return array_sum($numbers) / $count;
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}
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/**
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* Returns the median of the numbers in the array.
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*/
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public static function median(array $numbers): float|int
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{
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$count = count($numbers);
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if ($count === 0) {
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throw new StatisticsException('The array can not be empty.');
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}
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sort($numbers);
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$middle = (int) ($count / 2);
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if ($count % 2 === 0) {
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return ($numbers[$middle - 1] + $numbers[$middle]) / 2;
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}
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return $numbers[$middle];
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}
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/**
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* Returns the mode of the values in the array.
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*/
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public static function mode(array $values): mixed
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{
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if (empty($values)) {
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throw new StatisticsException('The array can not be empty.');
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}
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$frequency = array_count_values($values);
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return array_keys($frequency, max($frequency))[0];
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}
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/**
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* Returns the midrange of the numbers in the array.
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*/
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public static function midrange(array $numbers): float|int
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{
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if (empty($numbers)) {
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throw new StatisticsException('The array can not be empty.');
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}
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return (min($numbers) + max($numbers)) / 2;
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}
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/**
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* Returns the variance of the numbers in the array.
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*/
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public static function sampleVariance(array $numbers): float|int
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{
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$count = count($numbers);
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if ($count === 0) {
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throw new StatisticsException('The array can not be empty.');
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}
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$mean = self::mean($numbers);
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$variance = 0;
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foreach ($numbers as $number) {
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$variance += ($number - $mean) ** 2;
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}
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return $variance / ($count - 1);
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}
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/**
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* Returns the variance of the numbers in the array.
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*/
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public static function populationVariance(array $numbers): float|int
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{
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$count = count($numbers);
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if ($count === 0) {
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throw new StatisticsException('The array can not be empty.');
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}
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$mean = self::mean($numbers);
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$variance = 0;
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foreach ($numbers as $number) {
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$variance += ($number - $mean) ** 2;
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}
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return $variance / $count;
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}
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}

‎src/mako/utility/exceptions/StatisticsException.php

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<?php
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/**
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* @copyright Frederic G. Østby
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* @license http://www.makoframework.com/license
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*/
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namespace mako\utility\exceptions;
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use RuntimeException;
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/**
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* Statistics exception.
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*/
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class StatisticsException extends RuntimeException
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{
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}

‎tests/unit/utility/StatisticsTest.php

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<?php
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/**
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* @copyright Frederic G. Østby
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* @license http://www.makoframework.com/license
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*/
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namespace mako\tests\unit\utility;
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use mako\tests\TestCase;
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use mako\utility\exceptions\StatisticsException;
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use mako\utility\Statistics;
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use PHPUnit\Framework\Attributes\Group;
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#[Group('unit')]
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class StatisticsTest extends TestCase
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{
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/**
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*
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*/
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public function testMean(): void
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{
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$this->assertSame(7, Statistics::mean([1, 3, 5, 7, 9, 11, 13]));
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$this->assertSame(6, Statistics::mean([1, 3, 5, 7, 9, 11]));
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$this->assertEqualsWithDelta(1.8666666666666665, Statistics::mean([-11, 5.5, -3.4, 7.1, -9, 22]), 0.000000000000001);
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}
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/**
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*
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*/
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public function testMeanWithEmptyArray(): void
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{
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$this->expectException(StatisticsException::class);
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Statistics::mean([]);
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}
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/**
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*
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*/
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public function testMedian(): void
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{
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$this->assertSame(7, Statistics::median([1, 3, 5, 7, 9, 11, 13]));
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$this->assertSame(6, Statistics::median([1, 3, 5, 7, 9, 11]));
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$this->assertSame(1.05, Statistics::median([-11, 5.5, -3.4, 7.1, -9, 22]));
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}
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/**
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*
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*/
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public function testMedianWithEmptyArray(): void
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{
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$this->expectException(StatisticsException::class);
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Statistics::median([]);
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}
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/**
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*
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*/
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public function testMode(): void
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{
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$this->assertSame(3, Statistics::mode([1, 3, 3, 3, 5, 7, 7, 9]));
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$this->assertSame(1, Statistics::mode([1, 1, -3, 3, 7, -9]));
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$this->assertSame('red', Statistics::mode(['red', 'green', 'blue', 'red']));
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}
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/**
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*
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*/
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public function testModeWithEmptyArray(): void
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{
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$this->expectException(StatisticsException::class);
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Statistics::mode([]);
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}
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/**
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*
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*/
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public function testMidrange(): void
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{
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$this->assertSame(7, Statistics::midrange([1, 3, 5, 7, 9, 11, 13]));
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$this->assertSame(6, Statistics::midrange([1, 3, 5, 7, 9, 11]));
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$this->assertSame(5.5, Statistics::midrange([-11, 5.5, -3.4, 7.1, -9, 22]));
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}
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/**
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*
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*/
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public function testMidrangeWithEmptyArray(): void
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{
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$this->expectException(StatisticsException::class);
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Statistics::midrange([]);
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}
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/**
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*
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*/
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public function testSampleVariance(): void
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{
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$this->assertSame(14, Statistics::sampleVariance([1, 3, 5, 7, 9, 11]));
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$this->assertEqualsWithDelta(0.4796666666666667, Statistics::sampleVariance([2, 2.5, 1.25, 3.1, 1.75, 2.8]), 0.000000000000001);
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$this->assertEqualsWithDelta(70.80333333333334, Statistics::sampleVariance([-11, 5.5, -3.4, 7.1]), 0.0000000000001);
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$this->assertEqualsWithDelta(1736.9166666666667, Statistics::sampleVariance([1, 30, 50, 100]), 0.000000000001);
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}
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/**
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*
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*/
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public function testSampleVarianceWithEmptyArray(): void
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{
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$this->expectException(StatisticsException::class);
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Statistics::sampleVariance([]);
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}
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/**
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*
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*/
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public function testPopulationVariance(): void
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{
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$this->assertEqualsWithDelta(11.666666666666666, Statistics::populationVariance([1, 3, 5, 7, 9, 11]), 0.000000000000001);
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$this->assertEqualsWithDelta(0.3997222222222222, Statistics::populationVariance([2, 2.5, 1.25, 3.1, 1.75, 2.8]), 0.000000000000001);
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$this->assertEqualsWithDelta(53.1025, Statistics::populationVariance([-11, 5.5, -3.4, 7.1]), 0.0001);
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$this->assertEqualsWithDelta(1302.6875, Statistics::populationVariance([1, 30, 50, 100]), 0.0001);
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}
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}

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