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Feb 18, 2014 at 19:13 comment added Philip Sorry, i wasn't precise enough. What i wanted to say is that when $f$ is an arbitrary pdf then $1/c f(x/c)$ is not necessarily a pdf, too. In addition i am a bit puzzled by the linear system of equations: Since Fourier transform is complex, the log is ambiguous. So it cannot be transformed back to receive $g$?
Feb 18, 2014 at 18:16 comment added Robert I was saying the if $g$ is a linear function, g cannot be a density (it cannot integrate to 1).
Feb 18, 2014 at 17:38 comment added Philip I don't get it. I thought the 1/c was necessary to make g(x/c) a pdf? Because if $\int f(x) = 1$, then $\int g(x/c)$ will not be 1.
Feb 18, 2014 at 16:55 comment added Robert No -- in fact, if g() is linear, it will not define a density at all. The above holds for a larger class of functions. You can easily reserve it (just write down the definition of Fourier). It holds for Lebesgue integrable functions.
Feb 18, 2014 at 16:50 comment added Philip ${\cal F}g'(\omega)=1/c{\cal F}g(\omega/c)$ does only hold for linear functions, right? So this approach only works if g() is linear.
Feb 16, 2014 at 20:24 comment added Philip c is known to me. g() and f() are continuous in principle. However, since i only have observations of Zi's i can only calculate a discrete pdf.
Feb 16, 2014 at 16:42 history edited Robert CC BY-SA 3.0
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Feb 15, 2014 at 1:41 history edited Robert CC BY-SA 3.0
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Feb 15, 2014 at 0:40 history edited Robert CC BY-SA 3.0
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Feb 15, 2014 at 0:36 comment added Robert I see I can add comments here -- I edited the above already in regards to your comment.
Feb 15, 2014 at 0:34 history edited Robert CC BY-SA 3.0
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Feb 14, 2014 at 19:31 comment added Jochen Wengenroth Forier transformation is of course a good idea. However, how do you solve the equation $c\hat{f}(x) =\hat{g}(x)\hat{g} (x/c)$ in an efficient way to calulate $g$ by means of the Fourier inversion formula?
Feb 14, 2014 at 17:20 history edited Robert CC BY-SA 3.0
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Feb 14, 2014 at 17:11 history answered Robert CC BY-SA 3.0