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Saída de MIME Não-Texto> <stats_stat_powersum
Last updated: Fri, 13 Nov 2009

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stats_variance

(PECL stats >= 1.0.0)

stats_varianceReturns the population variance

Descrição

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

Esta função não está documentada; somente a lista de argumentos está disponível.

Parâmetros

a

sample

Valor Retornado



add a note add a note User Contributed Notes
stats_variance
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.

Saída de MIME Não-Texto> <stats_stat_powersum
Last updated: Fri, 13 Nov 2009
 
 
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