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

[Kevin O. <rko...@gm...>]

On Tue, Jul 31, 2018 at 8:49 PM, Kevin Oberman <rko...@gm...> wrote:

> On Tue, Jul 31, 2018 at 12:38 PM, Ethan Merritt <eam...@gm...>
> wrote:
>
>> 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
>>
>
> The 5.2 manual does not seem to mention "smooth Whittaker". Any idea where
> I might find some information on it, especially as used in gnuplot?
>

Never mind. DuckDuckGo found lots!
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rko...@gm...
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683