Statistic functions created (maybe will get moved to stochastics)

Math/Statistic/Average.php

@@ -0,0 +1,148 @@
+<?php
+namespace phpOMS\Math\Statistic;
+
+class Average
+{
+
+    public static function weightedAverage(array $value, array $weight)
+    {
+        if (($count = count($value)) !== count($weight)) {
+            throw new \Exception('Dimension');
+        }
+
+        $avg = 0.0;
+
+        for ($i = 0; $i < $count; $i++) {
+            $avg += $value[$i] * $weight[$i];
+        }
+
+        return $avg;
+    }
+
+    public static function mode($values)
+    {
+        $count = array_count_values($values);
+        $best  = max($count);
+
+        return array_keys($count, $best);
+    }
+
+    public static function median(array $values)
+    {
+        sort($values);
+        $count     = count($values);
+        $middleval = (int) floor(($count - 1) / 2);
+
+        if ($count % 2) {
+            $median = $values[$middleval];
+        } else {
+            $low    = $values[$middleval];
+            $high   = $values[$middleval + 1];
+            $median = (($low + $high) / 2);
+        }
+
+        return $median;
+    }
+
+    public static function arithmeticMean(array $values, \int $offset = 0)
+    {
+        sort($values);
+
+        if ($offset > 0) {
+            $values = array_slice($values, $offset, -$offset);
+        }
+
+        $count = count($values);
+
+        if ($count === 0) {
+            throw new \Exception('Division zero');
+        }
+
+        return array_sum($values) / $count;
+    }
+
+    public static function geometricMean(array $values)
+    {
+        $count = count($values);
+
+        if ($count === 0) {
+            throw new \Exception('Division zero');
+        }
+
+        return pow(array_product($values), 1 / $count);
+    }
+
+    public static function harmonicMean(array $values)
+    {
+        $count = count($values);
+        $sum   = 0.0;
+
+        foreach ($values as $value) {
+            if ($value === 0) {
+                throw new \Exception('Division zero');
+            }
+
+            $sum += 1 / $value;
+        }
+
+        return 1 / ($sum / $count);
+    }
+
+    public static function angleMean($angles)
+    {
+        $y    = $x = 0;
+        $size = count($angles);
+
+        for ($i = 0; $i < $size; $i++) {
+            $x += cos(deg2rad($angles[$i]));
+            $y += sin(deg2rad($angles[$i]));
+        }
+
+        $x /= $size;
+        $y /= $size;
+
+        return rad2deg(atan2($y, $x));
+    }
+
+    public static function timeToAngle(\string $time)
+    {
+        $parts = explode(':', $time);
+
+        if (count($parts) !== 3) {
+            throw new \Exception('Wrong time format');
+        }
+
+        $sec   = ($parts[0] * 3600) + ($parts[1] * 60) + $parts[2];
+        $angle = 360.0 * ($sec / 86400.0);
+
+        return $angle;
+    }
+
+    public static function angleToTime(\float $angle)
+    {
+        $sec   = 86400.0 * $angle / 360.0;
+        $parts = [floor($sec / 3600), floor(($sec % 3600) / 60), $sec % 60];
+        $time  = sprintf('%02d:%02d:%02d', $parts[0], $parts[1], $parts[2]);
+
+        return $time;
+    }
+
+    public static function angleMean2(array $angle)
+    {
+        $sins = 0.0;
+        $coss = 0.0;
+
+        foreach ($angle as $a) {
+            $sins += sin(deg2rad($a));
+            $coss += cos(deg2rad($a));
+        }
+
+        $avgsin = $sins / (0.0 + count($angle));
+        $avgcos = $coss / (0.0 + count($angle));
+        $avgang = rad2deg(atan2($avgsin, $avgcos));
+
+        while ($avgang < 0.0) $avgang += 360.0;
+
+        return $avgang;
+    }
+}

Math/Statistic/Basic.php

@@ -0,0 +1,24 @@
+<?php
+namespace phpOMS\Math\Statistic;
+
+class Basic
+{
+    public static function freaquency(array $values) : \float
+    {
+        $freaquency = [];
+
+        if (!($isArray = is_array(reset($values)))) {
+            $sum = array_sum($values);
+        }
+
+        foreach ($values as $value) {
+            if ($isArray) {
+                $freaquency[] = self::freaquency($value);
+            } else {
+                $freaquency[] = $value / $sum;
+            }
+        }
+
+        return $freaquency;
+    }
+}

Math/Statistic/MeasureOfDispersion.php

@@ -0,0 +1,87 @@
+<?php
+namespace phpOMS\Math\Statistic;
+
+class MeasureOfDispersion
+{
+    public static function range($values)
+    {
+        $end   = end($values);
+        $start = reset($values);
+
+        return $start - $end;
+    }
+
+    public static function empiricalVariance($values)
+    {
+        $count = count($values);
+
+        if ($count === 0) {
+            throw new \Exception('Division zero');
+        }
+
+        $mean = Average::arithmeticMean($values);
+        $sum  = 0;
+
+        foreach ($values as $value) {
+            $sum += $value - $mean;
+        }
+
+        return $sum / $count;
+    }
+
+    public static function sampleVariance($values)
+    {
+        $count = count($values);
+
+        if ($count < 2) {
+            throw new \Exception('Division zero');
+        }
+
+        return $count * self::empiricalVariance($values) / ($count - 1);
+    }
+
+    public static function standardDeviation($values)
+    {
+        return sqrt(self::sampleVariance($values));
+    }
+
+    public static function empiricalVariationcofficient($values)
+    {
+        $mean = Average::arithmeticMean($values);
+
+        if ($mean === 0) {
+            throw new \Exception('Division zero');
+        }
+
+        return self::standardDeviation($values) / $mean;
+    }
+
+    public static function empiricalCovariance($x, $y)
+    {
+        $count = count($x);
+
+        if ($count < 2) {
+            throw new \Exception('Division zero');
+        }
+
+        if ($count !== count($y)) {
+            throw new \Exception('Dimensions');
+        }
+
+        $xMean = Average::arithmeticMean($x);
+        $yMean = Average::arithmeticMean($y);
+
+        $sum = 0.0;
+
+        for ($i = 0; $i < $count; $i++) {
+            $sum += ($x[$i] - $xMean) * ($y[$i] - $yMean);
+        }
+
+        return $sum / ($count - 1);
+    }
+
+    public static function bravaisPersonCorrelationcoefficient($x, $y)
+    {
+        return self::empiricalCovariance($x, $y) / sqrt(self::empiricalCovariance($x, $x) * self::empiricalCovariance($y, $y));
+    }
+}