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 toFALSE
.
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
.