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astrorama / SourceXtractorPlusPlus

SourceXtractor++, the next generation SExtractor
https://astrorama.github.io/SourceXtractorPlusPlus/
GNU Lesser General Public License v3.0
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Scaling for the modified chi-square #487

Closed mkuemmel closed 2 years ago

mkuemmel commented 2 years ago

The documentation states that the scaling for the modified chi-square fit (https://astrorama.github.io/SourceXtractorPlusPlus/Model.html#modified-least-squares) involves the rms of the pixel (u_0 = kappa * sigma_i). In contrast the implementation uses a fixed scaling of value 10: https://github.com/astrorama/SourceXtractorPlusPlus/blob/develop/ModelFitting/ModelFitting/Engine/AsinhChiSquareComparator.h That does not seem to be a big deals otherwise we would have realized that inconsistency earlier on. But it would be good to settle this.

mkuemmel commented 2 years ago

We had a long discussion on that one. @ebertin will look at the equations and decide what is correct.

ebertin commented 2 years ago

Equations fixed in 9d8bccb. Code matches the equations