39 lines
931 B
Plaintext
39 lines
931 B
Plaintext
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{{alias}}( α )
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Returns an accumulator function which incrementally computes an
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exponentially weighted standard deviation, where α is a smoothing factor
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between 0 and 1.
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If provided a value, the accumulator function returns an updated standard
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deviation. If not provided a value, the accumulator function returns the
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current standard deviation.
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If provided `NaN` or a value which, when used in computations, results in
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`NaN`, the accumulated value is `NaN` for all future invocations.
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Parameters
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----------
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α: number
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Smoothing factor (value between 0 and 1).
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Returns
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-------
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acc: Function
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Accumulator function.
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Examples
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--------
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> var accumulator = {{alias}}( 0.5 );
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> var s = accumulator()
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null
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> s = accumulator( 2.0 )
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0.0
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> s = accumulator( -5.0 )
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3.5
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> s = accumulator()
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3.5
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See Also
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--------
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