stats_stat_powersum
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.
stats_variance
(PECL stats >= 1.0.0)
stats_variance — Retourne la variance d'une population
Description
float stats_variance
( array $a
[, bool $sample = false
] )
Avertissement
Cette fonction n'est pas documentée et seule la liste des arguments est disponible.
Liste de paramètres
- a
-
- sample
-
Valeurs de retour
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User Contributed Notes
stats_variance
Anonymous
27-Feb-2009 01:43