Class
NumCosmoXcorComponentTable
Description [src]
final class NumCosmo.XcorComponentTable : GObject.Object
{
/* No available fields */
}One tabulated component of a radial window: $(\chi, W)$ samples plus what the window is a window of.
A tracer is in general a sum of terms with different Bessel weights and
$\ell$ prefactors: a galaxy-count tracer has a density term weighted by
$j_\ell$, a redshift-space distortion term weighted by $j_\ell”$ and a
magnification term weighted by $j_\ell/(k\chi)^2$ with an $\ell(\ell+1)$
prefactor. Each of those is one of these objects; NcXcorKernelTable holds
the list and integrates every component over its own support.
The samples are reconstructed with a NcmSplineBSpline of the requested
order (degree 7 by default: a cubic caps a 2000-sample window at
$\sim 10^{-8}$ while degree 7 reaches $\sim 10^{-15}$ from the same data).
Leading and trailing runs of exact zeros are trimmed, keeping one zero on
each side so the reconstruction still goes to zero at the reported edge.
The convention is NcXcorKernelRadial‘s: $\chi$ in Mpc, $P(k)$ at $z = 0$
and all redshift dependence — growth included — carried by $W$.
For the kinds that carry $1/(k\chi)^2$ the reported support never starts at
the origin. A lensing window is linear in $\chi$ there, so $W/\chi^2$ is a
$1/\chi$ the solver handles but the origin itself is not a valid lower limit;
when the table’s support starts below NC_XCOR_COMPONENT_TABLE_CHI_FLOOR
(0.01 Mpc) it is moved there. The window omitted below that point is
$\sim W’(0)\,\chi_\mathrm{min}^2/2$, negligible for any survey window. The
floor is a fixed distance, not a fraction of the sample spacing: the closure’s
$k$ range for these kinds grows as the inverse of the lower limit, and a
4000-sample lensing table with the floor at a thousandth of its first sample
(1.5 Mpc) cost seven times the same window tabulated on 1000 samples.
Constructors
nc_xcor_component_table_new
Creates a density component of default order, normalized to unit integral.
Instance methods
nc_xcor_component_table_eval_kernel_factor
Evaluates the $(\chi, k)$ factor the kind carries: $1/(k\chi)^2$ for
NC_XCOR_KERNEL_TABLE_KIND_SHEAR and NC_XCOR_KERNEL_TABLE_KIND_CONVERGENCE,
1 otherwise.
nc_xcor_component_table_eval_prefactor
Evaluates the $\ell$ prefactor the kind carries:
$\sqrt{(\ell+2)(\ell+1)\ell(\ell-1)}$ for NC_XCOR_KERNEL_TABLE_KIND_SHEAR
(zero where the radicand is not positive), $\ell(\ell+1)$ for
NC_XCOR_KERNEL_TABLE_KIND_CONVERGENCE, 1 otherwise.
nc_xcor_component_table_get_bessel_deriv
Gets the derivative order of the spherical Bessel weight: 2 for
NC_XCOR_KERNEL_TABLE_KIND_RSD, 0 otherwise.
nc_xcor_component_table_get_norm
Gets the integral of the supplied table over its support, which the window
is divided by when NcXcorComponentTable:normalize is set, or 1 otherwise.
nc_xcor_component_table_get_support
Gets the interval the component is integrated over. It is the trimmed table’s range, except that a $1/(k\chi)^2$ kind never starts at the origin (see the class documentation).
nc_xcor_component_table_peek_knots
Gets the abscissae the reconstruction is built on: the supplied samples with the leading and trailing zero runs trimmed.
nc_xcor_component_table_peek_spline
Gets the reconstruction of the supplied samples, before normalization.
nc_xcor_component_table_set_samples
Replaces the tabulated samples and rebuilds the reconstruction, keeping the
kind, order and normalization. The table may change length. This is how a
sampler feeds a new cosmology’s window into a kernel that stays registered
with its NcXcorSolver, so the solver’s per-block integrators survive the
step; the owning kernel must be told through nc_xcor_kernel_mark_outdated(),
which nc_xcor_kernel_table_replace_samples() does.
Properties
NumCosmo.XcorComponentTable:kind
What the window is a window of, which fixes the Bessel weight and the factors applied on top of it.
NumCosmo.XcorComponentTable:normalize
Whether to rescale the window to unit integral over its support. Turn it off when the supplied table is already normalized in the same convention, or when it is one term of a tracer whose relative amplitudes must be kept.
NumCosmo.XcorComponentTable:order
B-spline order of the reconstruction; the degree is one less. The default is degree 7, not a cubic: a cubic caps a 2000-sample window at $\sim 10^{-8}$ while degree 7 reaches $\sim 10^{-15}$ from the same data.
Signals
Signals inherited from GObject (1)
GObject::notify
The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.