Enumeration
NumCosmoXcorMethod
Description [src]
Methods to compute integrals.
The kernel-space methods share one closure across a whole
NcXcor:ell-batch-size block, fitted to an $L^2$ norm over the block. With
NcXcor:ell-batch-size 1 each multipole gets its own closure, the
independent check that does not share a closure with anything.
NC_XCOR_METHOD_KERNEL_EXACT needs no tolerance and cannot fail to converge.
The name is meant literally rather than as “fixed-order”: on the closures it
is handed, the quadrature carries no error at all, and refining its panels
changes nothing beyond rounding.
It uses the same per-kernel closures as NC_XCOR_METHOD_KERNEL_CUBATURE and
differs only in the outer quadrature: each kernel’s $W(k)$ is a cubic spline,
so on the common refinement of a pair’s two knot sets the outer integrand
$k^2 W_i W_j$ is a degree-8 polynomial on every panel, and a 5-node
Gauss-Legendre rule integrates it exactly. The adaptive alternatives target a
tolerance the integrand may not be able to support, and abort when they
cannot reach it.
Measured over 28 pairs of 7 top-hat bins it is also slightly faster than
NC_XCOR_METHOD_KERNEL_CUBATURE (1.05x at $\ell = 0$, 1.18x over
$\ell = 0\dots26$), since the exact rule replaces adaptive refinement on
splines that have already been built.
Members
-
NC_XCOR_METHOD_LIMBER_Z_GSL -
Use GSL numerical integration.
- Value:
0 - Available since: 1.0
- Value:
-
NC_XCOR_METHOD_LIMBER_Z_CUBATURE -
Use cubature numerical integration.
- Value:
1 - Available since: 1.0
- Value:
-
NC_XCOR_METHOD_KERNEL_CUBATURE -
Use cubature numerical integration over kernel variables.
- Value:
2 - Available since: 1.0
- Value:
-
NC_XCOR_METHOD_KERNEL_EXACT -
Integrate the kernel closures exactly, on the union of their own knots.
- Value:
3 - Available since: 1.0
- Value:
Type functions
nc_xcor_method_has_error_estimate
Whether meth fills the vp_err of nc_xcor_compute_full() and
nc_xcor_integrate_block(). Every other method leaves it alone rather than
writing a zero that would read as “no error”, so a caller that wants an
estimate has to ask this first.
nc_xcor_method_is_kernel_space
Whether meth integrates over $k$ with a pair of fitted closures, as opposed
to the redshift-space Limber tier.