stats_standard_deviation

(PECL stats >= 1.0.0)

stats_standard_deviation — Returns the standard deviation

说明

stats_standard_deviation ( array $a [, bool $sample = FALSE ] ) : float

Returns the standard deviation of the values in a.

参数

a

The array of data to find the standard deviation for. Note that all values of the array will be cast to float.

sample

Indicates if a represents a sample of the population; defaults to FALSE.

返回值

Returns the standard deviation on success; FALSE on failure.

错误／异常

Raises an E_WARNING when there are fewer than 2 values in a.