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{{alias}}( W[, mx, my] )
Returns an accumulator function which incrementally computes a moving
sample Pearson product-moment correlation coefficient.
The `W` parameter defines the number of values over which to compute the
moving sample correlation coefficient.
If provided values, the accumulator function returns an updated moving
sample correlation coefficient. If not provided values, the accumulator
function returns the current moving sample correlation coefficient.
As `W` (x,y) pairs are needed to fill the window buffer, the first `W-1`
returned values are calculated from smaller sample sizes. Until the window
is full, each returned value is calculated from all provided values.
Parameters
----------
W: integer
Window size.
mx: number (optional)
Known mean.
my: number (optional)
Known mean.
Returns
-------
acc: Function
Accumulator function.
Examples
--------
> var accumulator = {{alias}}( 3 );
> var r = accumulator()
null
> r = accumulator( 2.0, 1.0 )
0.0
> r = accumulator( -5.0, 3.14 )
~-1.0
> r = accumulator( 3.0, -1.0 )
~-0.925
> r = accumulator( 5.0, -9.5 )
~-0.863
> r = accumulator()
~-0.863
See Also
--------
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