plima.backends.ccl.la#

CCL backend helpers for LA intrinsic alignment bias inputs.

This module connects PLIMA LA amplitude models to the IA bias tuple expected by CCL weak lensing tracers.

CCL weak lensing tracers expect the conventional user facing A_IA(z) amplitude when use_A_ia=True. CCL then applies the IA normalization and minus sign internally. Therefore this backend returns the PLIMA amplitude directly and does not flip its sign.

Functions

make_ccl_la_ia_bias(z, *[, amplitude, a_ia])

Return a CCL IA bias tuple for LA.
plima.backends.ccl.la.make_ccl_la_ia_bias(z, *, amplitude=None, a_ia=1.0)[source]#

Return a CCL IA bias tuple for LA.

This backend follows the PLIMA user-facing convention that positive A_IA corresponds to a positive LA amplitude. The returned ia_bias is the conventional A_IA(z) tuple expected by CCL when WeakLensingTracer(..., use_A_ia=True) is used.

Parameters:

  • z (ArrayLike) – Redshift values where the IA bias should be sampled.

  • amplitude (ArrayLike | float | None) – Optional precomputed positive LA amplitude evaluated at z. If None, the amplitude is computed from la_amplitude.

  • a_ia (float) – Positive LA amplitude normalization used when amplitude is None.

Returns:

Redshift values and conventional CCL A_IA(z) values sampled on the same grid.

Raises:

ValueError – If redshifts are not finite, redshifts are outside the valid domain, or amplitude cannot be broadcast to match z.

Return type:

tuple[NDArray[float64], NDArray[float64]]