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devil
02/07/13 1:08pm

In Response To 'Re: Re: Re: derivative of amplitude-frequency c...'
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Yes, you are right.

I get the same output.

ampl = 2 \[Pi] Abs[f/(1000 + 2 I f \[Pi])]

and the derivation of it is the same you said

2 \[Pi] (-((2 I f \[Pi])/(1000 + 2 I f \[Pi])^2) + 1/(
1000 + 2 I f \[Pi])) Derivative[1][Abs][f/(1000 + 2 I f \[Pi])]


I figure out that ampl is a real function. Im[ampl] is 0!

So thats why Mathematica have no problem to plot it.

The derivation is in addition imaginary ... so Mathematica don't know how to plot. Like you said.

But I can't explain why the derivation of a function should not exist, when I can plot the original function. There are no bounds in my plot.

LogLogPlot[ampl, {f, 0.0000001, 10000000}]

And that's why I think the derivation should exist.

Could the problem are the bounce by f=0 ?

Plot[ampl, {f, -100, 100}]

How can I limit the derivation from 0 to inf so that there are no more bounces?

Could this be the reason why Mathematica can't solve the derivation ?

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Subject (listing for 'derivative of amplitude-frequency characteristic')
Author Date Posted
derivative of amplitude-frequency characteristic devil 02/05/13 2:19pm
Re: derivative of amplitude-frequency character... Bill Simpson 02/05/13 6:43pm
Re: Re: derivative of amplitude-frequency chara... devil 02/06/13 2:22pm
Re: Re: Re: derivative of amplitude-frequency c... Bill Simpson 02/06/13 8:25pm
Re: Re: Re: Re: derivative of amplitude-frequen... devil 02/07/13 1:08pm
Re: derivative of amplitude-frequency character... devil 02/20/13 07:16am
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