DOC: Add ellipticity example #471
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Lucia-Fonseca
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Review comments addressed. |
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Some general comments:
- Calculating the variance from multiple simulations overcomplicates the code and distracts from the main purpose of the example. I would stick to just a single simulation as in our other examples.
- What is the source of the SDSS data? How was the file generated? Are we licensed to distribute it?
| # projected 2D axis ratios. Specifically, it samples the axis ratios of the | ||
| # 3D ellipsoid according to the description above [1] and | ||
| # then randomly projects them using | ||
| # :func:`skypy.utils.random.triaxial_axis_ratio()`. |
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Potentially confusing to mention the triaxial_axis_ratio function. It is hidden from the user who doesn't need to understand the implementation in this context.
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Not sure I agree, but I'm open to delete that bit.
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To be clear, we still want to explain the model (population of triaxial ellipsoids with some distribution in projection) but the implementation details (ryden04_ellipticity calls another function triaxial_axis_ratio) are at best irrelevant and at worst confusing for the user.
| lw=0.5, mew=0.5, label='SkyPy model') | ||
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| plt.xlabel(r'Axis ratio, $q_{am}$') | ||
| plt.ylabel(r'N') |
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Units? Do we know the area covered by the data?
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yes it's axis ratio and number of galaxies, the area shouldn't come into it
Yes, I agree. However, how could you generate the error bars otherwise? Or you are suggesting we simply draw one sim and plot the histogram? How can we convince the SkyPy model is compatible with SDSS data?
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No, I queried the data from the SDSS servers because I didn't know. |
Description
This PR includes the validation plot for the 3D ellipticity model (Ryden04) in the examples page.
It reproduces the distribution of axis ratio
𝑞_{am}for exponential galaxies in the SDSS DR1 as done by @ntessore here.Merging this PR closes #470.
Checklist
References