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stats_variance

(PECL stats >= 1.0.0)

stats_variance — Returns the population variance

说明

float stats_variance ( array $a [, bool $sample = false ] )

Warning

本函数还未编写文档，仅有参数列表。

参数

a
sample

返回值

在线手册：中文英文

PHP手册 - N: Returns the population variance

用户评论:

Anonymous (27-Feb-2009 09:43)

This will return surprising values for most users, since the default of sample=false is rather unusual when speaking about variance. Point is: When using stats_variance($foo,TRUE) the sum is divided by n-1 while the default just divides it by n. So when you expect your variance to be lower you probable wanted to divide by n-1, therefore should set the second parameter =TRUE.