search

msimet / Stile

Stile: the Systematics Tests In Lensing pipeline
BSD 3-Clause "New" or "Revised" License
9 stars 6 forks source link

Default parameters for correlation functions? #61

Open msimet opened 9 years ago

msimet commented 9 years ago

At the moment, when you run a correlation function test, you must specify the units of the ra and dec fields, plus the number of bins, min/max separation, and units for the output correlation function.

I'm wondering if it's worth trying to work out some simple defaults for these values. Getting a max ra range and dec range (or x and y range) could give us a max separation, we could work out a decent guess of a min separation based on the number of objects in the given rectangle, set a default number of bins (maybe based on the number of points available), and as long as the units are all the same it doesn't really matter what we call them. It likely wouldn't be perfect, especially for non-rectangular areas, but might be easier than figuring out these values for every correlation function you'd like to run. (They could all still be specified, of course--these would just be used for unspecified quantities.)

The counterargument, which I think is a big one, is that this is opaque to the end user and it might not be obvious if we picked something really wrong from the endpoints. Plus, the max separation for a xi-type correlation function is probably bigger than the desired max separation for e.g. tangential shear around bright stars.

Thoughts?

rmandelb commented 9 years ago

I like the idea of having simple defaults.