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rwesson / NEAT

Empirical analysis of ionised nebulae, with uncertainty propagation
GNU General Public License v3.0
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Weighting used to calculate abundances #24

Closed rwesson closed 11 years ago

rwesson commented 12 years ago

I've just made a change to this; see

https://github.com/rwesson/NEAT/commit/89e397d50b6a013ef15213b562d531338bcc119c

Previously, the weight used for each line when combining CEL abundances from individual lines was (Uncertainty/Flux)**-2. However, if the user were to input zero as an uncertainty, as they might if they don't have actual uncertainties to put it, this scheme gives infinite weights and Infs and NaNs start appearing.

So I've changed the weight to be just the intensity of the line. I'm opening this issue because there might be better schemes to use than this, and my change is just a bug fix rather than a definitive decision on what the best weighting scheme is.

rwesson commented 11 years ago

I think I'll close this, I don't see any disadvantage to the weighting scheme now in place. Feel free to reopen if you disagree guys.