Re: [Gnuplot-info] sin(x)/x smoothing option?

[Ethan M. <eam...@gm...>]

On Mon, Jul 30, 2018 at 5:10 PM, Reginald Beardsley via gnuplot-info <
gnu...@li...> wrote:

> Is there an option to apply a sin(x)/x aka Whittaker interpolator to the
> points when plotting?  I'm working on a digital signal processing tutorial
> and it would be helpful to be able to apply a sinc interpolator to the data
> points.
>
> If there is not, I'd like to suggest considering that as an enhancement as
> it is widely used in DSP applications.
>

Not my field, so I'm working with the assistance of Wikipedia.
Do I understand correctly that the idea would be to plot the function

      f(x) = Summation_over_all_data { yn * sinc( (x - nT)/T )}

where the original data points were [xn, yn] and T = 1/(2*bandwidth) is a
constant specified by the user?
Analogous to the kdensity smoothing option, the plot command would be

     plot $DATA smooth Whittaker {bandwidth <value>}

In the case of kernel density smoothing there is an obvious default for the
bandwidth.
Is there something similar for this formula or would the bandwidth always
be required?
Would it be more natural to provide T or to provide bandwidth?

    Ethan