Make tracer spline errors more verbose

[tilmantroester]

This catches the case where the tracer redshift support is wider than the interal background spline. This is mostly useful to prevent opaque error in calculator mode. A similar check should probably be made for the power spectrum as well.

[coveralls]

Pull Request Test Coverage Report for Build 2167561237

• 37 of 39 (94.87%) changed or added relevant lines in 12 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.005%) to 97.052%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pyccl/halos/halo_model.py	5	6	83.33%
pyccl/halos/hbias.py	1	2	50.0%

Totals
Change from base Build 1922185518:	0.005%
Covered Lines:	4411
Relevant Lines:	4545

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💛 - Coveralls

[damonge]

This looks good to me. Have you checked if this adds a lot of time to the usual life cycle of a tracer? I assume not, but I forget if _get_spline1d_array was a costly function.

[damonge]

Also, could we add a unit test that makes this fail?

[tilmantroester]

Added a unit test. _get_spline1d_array just copies the memory of the C-level spline data, so should be negligible in terms of computational effort. On the other hand it shouldn't be necessary. Maybe I'll add a a_min and a_max to the cosmo.data C-struct for bookkeeping.

[damonge]

Thanks a lot!
I'm happy to approve this without the C-level logging of amin/max as soon as the final tests pass.

[damonge]

LGTM