<?php namespace PhpOffice\PhpSpreadsheet\Calculation\Statistical; class StandardDeviations { /** * STDEV. * * Estimates standard deviation based on a sample. The standard deviation is a measure of how * widely values are dispersed from the average value (the mean). * * Excel Function: * STDEV(value1[,value2[, ...]]) * * @param mixed ...$args Data values * * @return float|string The result, or a string containing an error */ public static function STDEV(...$args) { $result = Variances::VAR(...$args); if (!is_numeric($result)) { return $result; } return sqrt((float) $result); } /** * STDEVA. * * Estimates standard deviation based on a sample, including numbers, text, and logical values * * Excel Function: * STDEVA(value1[,value2[, ...]]) * * @param mixed ...$args Data values * * @return float|string */ public static function STDEVA(...$args) { $result = Variances::VARA(...$args); if (!is_numeric($result)) { return $result; } return sqrt((float) $result); } /** * STDEVP. * * Calculates standard deviation based on the entire population * * Excel Function: * STDEVP(value1[,value2[, ...]]) * * @param mixed ...$args Data values * * @return float|string */ public static function STDEVP(...$args) { $result = Variances::VARP(...$args); if (!is_numeric($result)) { return $result; } return sqrt((float) $result); } /** * STDEVPA. * * Calculates standard deviation based on the entire population, including numbers, text, and logical values * * Excel Function: * STDEVPA(value1[,value2[, ...]]) * * @param mixed ...$args Data values * * @return float|string */ public static function STDEVPA(...$args) { $result = Variances::VARPA(...$args); if (!is_numeric($result)) { return $result; } return sqrt((float) $result); } }