tkremund98 wrote:
>> On Feb 26, 3:26=A0pm, "tkremund98" <tkremun...@hotmail.com> wrote:
>>>> On Feb 26, 2:54=3DA0pm, "tkremund98" <tkremun...@hotmail.com> wrote:
>>>>> This is just a question about Gibb's effect. Is Gibb's Effect is
>>> present =3D
>>>> in
>>>>> stationary data?
>>>> yes
>>> Do you believe that the Gibb's is significant in comparison with the
>>> general spread of the data?
>> I'm not trying to be glib, but if you try to make a very narrow
>> bandpass filter using a brickwall approach ( for example), the ringing
>> is very apparent. Will the ringing be a problem - maybe - depends on
>> the app.
>>
>> Which aspect of Gibb's is a concern for you? Are you interested in the
>> Wilbrahem constant? Are you concerned with trying to approximate a
>> piecewise continuous function with a sum of uniformly continuous
>> ones? The far field distribution of E-M radiation is the Fourier
>> transform of the near field illumination current - are the side lobes
>> an issue?
>>
>> If you can add some more detail to the question, I feel that I and
>> others can better answer your question. In optics you can see Gibb's
>> phenomina quite well. Look up Fresnel Integrals and their use in
>> Cornu's spiral to figure the strength of the diffracted (spread)
>> signal. This holds for radio waves as well.
>>
>> Clay
>>
>
> I'm actually somewhat crosstraining into DSP methods after receiving a
> degree in statistics. In other words, I'm somewhat wet behind the ears
> still. I notice that after having filtering data with a windowed-sinc
> filter I have the usual ring in the neighborhood of a step function but it
> dies out. Seeing this prodded some investigation. I tried some
> simulations using a signal simulated using user specified amplitudes for
> sine and cosine waves and combining using a synthesis equation. Then I
> superimposed this on a hard step function. When I vary the magnitude of
> the step function from large to small the ring disappears into the data and
> is seemingly indistiguishable from the data after having filtered it.
>
> I really appreciate the help, thanks!

The ringing amplitude is proportional to the step amplitude. If you
smack a bell with a hammer, there will be a much louder clang than if
you hit it with a water hose.

Jerry
--
Engineering is the art of making what you want from things you can get.
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