ChartDirector 7.0 (PHP Edition)

ArrayMath.movStdDev


Usage

movStdDev(interval)

Description

Replaces each element of the ArrayMath object by its moving standard deviation.

The interval parameter specifies the window size for computing moving average. The moving average is computed as the standard deviation of the current element with the previous (interval - 1) elements. No moving standard deviation can be computed for the first (interval - 1) elements, because there are insufficient previous elements. So the first (interval - 1) elements will be replaced with NoValue.

Arguments

ArgumentDefaultDescription
interval(Mandatory)The window size.

Return Value

The current ArrayMath object.