a or z : that is the question!
Opened this issue · 5 comments
Should all functions be parameterized by the redshift z or the scale factor a ?
I have heard both sides on this.... I have had a preference myself for a in the past, but I'm getting very annoyed at having to convert between redshift and scale factors all the time....
Could we just parameterize everything in terms of z and call it a day?
I would also argue for z, it simplifies many things like integrals along z and redshift space quantities. Also some other equations can be written more compactly.
I think it makes sense to any observational cosmologist, who would think in terms of redshift, not scale factor, so I think I'm pro z !
Will propose an API change
Should this also depend on the accuracy of integration in a vs in z? I guess it's related to the smoothness of the integrand as function of each variable.
Yeahhhh, but you can convert z to a wherever needed for numerical integration, it's more a question of what the user interface will look like.
So actually ^^' I implemented a redshift only version of the API but it makes all background stuff very awkward, you have to convert to scale factor all the time, so I'm not sure ^^'