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VEWOXIC / FITS

FITS: Frequency Interpolation Time Series Analysis Baseline
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`Real_FITS.py` implementation detail #3

Closed csguoh closed 5 months ago

csguoh commented 5 months ago

Hi, authors Thx for this incredible work! I have a question about the code implementation of this line in Real_FITS.py. I can not figure out why use the real+ imag / real-imag to generate the results. Why not directly generate the real or image with the corresponding layer? I would appreciate if you could explain this.

Thx ;D

VEWOXIC commented 5 months ago

Thanks for being interested in our work! XD

FITS fundamentally works as multiplying a complex vector $X$ by a complex weight matrix $W$.

$$ Y=X * W $$

However, if we break it down to real number computation, it should be:

$$ Y{real} = X{real} W{real} - X{imag} W_{imag} $$

$$ Y{imag} = X{real} W{imag} + X{imag} W_{real} $$

That is exactly what we do in the FITS_real, simulating this break down.

Hope this can help you.

VEWOXIC commented 5 months ago

I have added a comment in real_FITS.py for this! :D

csguoh commented 5 months ago

Thx for your detailed explanation!