Posted by
Herbie-4 on
Sep 29, 2014; 10:29am
URL: http://imagej.273.s1.nabble.com/1D-Fourier-transform-in-macro-tp5009727p5009815.html
Good day Michael and Wayne,
the IJ-macro routine Array.fourier(...) is good news, but why not
optionally output the complex-valued 1D Fourier transform?
One may add a third parameter that, if not present, will result in the
magnitude of the 1D Fourier transform. Otherwise the parameter indicates
that the complex-valued 1D Fourier transform (real & imaginary, or
magnitude & phase) is to be returned.
A possible array format for the transform is discussed in "Numerical
Recipes". It is based on the fact that the first and last imaginary
values are known to be zero and therefore need not be stored in the array.
Just a suggestion...
Best regards
Herbie
::::::::::::::::::::::::::::::::::::::::
On 28.09.14 21:12, Michael Schmid wrote:
> Hi Ludovic,
>
> in the latest daily build, Wayne has added an Array.fourier(theArray,
> windowType) macro function, based on code snippets that I have sent to
> him. Use Help>Update ImageJ to obtain the daily build.
>
> There is some documentation and a text macro for the new function at
>
>
http://imagej.nih.gov/ij/macros/examples/TestArrayFourier.txt>
> In your case, with data values approaching (or equel to) zero at the
> beginning and end of the array, you don't need a window function; simply
> omit that parameter or write "none" (with the quotes!) for the windowType.
>
> Michael
>
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