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Functions
Properties
double | lnr0 | Read / Write |
NcmPowspec * | powerspectrum | Read / Write / Construct Only |
double | reltol | Read / Write / Construct |
double | reltol-z | Read / Write / Construct |
double | zf | Read / Write |
double | zi | Read / Write |
Description
This class computes the 3d spatial correlation function $\xi(r, z)$ from the power spectrum using the FFTLog approach (see NcmFftlog and NcmFftlogSBesselJ), \begin{equation}\label{eq:variance} \xi(r, z) = \sigma^2(r, z) = \frac{1}{2\pi^2} \int_0^\infty k^2 \ P(k, z) j_0(kr) \ \mathrm{d}k, \end{equation} where $P(k, z)$ is the power spectrum at mode $k$ and redshift $z$ and $j_0(kr)$ is the order zero spherical bessel function.
Functions
ncm_powspec_corr3d_new ()
NcmPowspecCorr3d *
ncm_powspec_corr3d_new (NcmPowspec *ps
);
Creates a new NcmPowspecCorr3d from the power spectrum ps
.
ncm_powspec_corr3d_ref ()
NcmPowspecCorr3d *
ncm_powspec_corr3d_ref (NcmPowspecCorr3d *psc
);
Increases the reference count of psc
by one.
ncm_powspec_corr3d_free ()
void
ncm_powspec_corr3d_free (NcmPowspecCorr3d *psc
);
Decreases the reference count of psc
by one.
ncm_powspec_corr3d_clear ()
void
ncm_powspec_corr3d_clear (NcmPowspecCorr3d **psc
);
If psc
is different from NULL, decreases the reference count of
psc
by one and sets fftlog
to NULL.
ncm_powspec_corr3d_prepare ()
void ncm_powspec_corr3d_prepare (NcmPowspecCorr3d *psc
,NcmModel *model
);
Prepares the object applying the filter to the power spectrum.
ncm_powspec_corr3d_prepare_if_needed ()
void ncm_powspec_corr3d_prepare_if_needed (NcmPowspecCorr3d *psc
,NcmModel *model
);
Prepares (if necessary) the object applying the filter to the power spectrum.
ncm_powspec_corr3d_set_lnr0 ()
void ncm_powspec_corr3d_set_lnr0 (NcmPowspecCorr3d *psc
,gdouble lnr0
);
Sets the center of the transform output $\ln(r_0)$ (see ncm_fftlog_set_lnr0()
).
ncm_powspec_corr3d_set_best_lnr0 ()
void
ncm_powspec_corr3d_set_best_lnr0 (NcmPowspecCorr3d *psc
);
Sets the value of $\ln(r_0)$ which gives the best results for
the transformation based on the current value of $\ln(k_0)$,
this is based in the rule of thumb $\mathrm{max}_{x^*}(j_l)$
where $ x^* \approx l + 1$ (see ncm_fftlog_sbessel_j_set_best_lnr0()
).
ncm_powspec_corr3d_set_zi ()
void ncm_powspec_corr3d_set_zi (NcmPowspecCorr3d *psc
,gdouble zi
);
Sets the inital time $z_i$.
ncm_powspec_corr3d_set_zf ()
void ncm_powspec_corr3d_set_zf (NcmPowspecCorr3d *psc
,gdouble zf
);
Sets the final time $z_f$.
ncm_powspec_corr3d_get_r_min ()
gdouble
ncm_powspec_corr3d_get_r_min (NcmPowspecCorr3d *psc
);
This function returns $\xi(r, z)$'s minimum evaluated distance.
ncm_powspec_corr3d_get_r_max ()
gdouble
ncm_powspec_corr3d_get_r_max (NcmPowspecCorr3d *psc
);
This function returns $\xi(r, z)$'s maximum evaluated distance.
ncm_powspec_corr3d_eval_xi_lnr ()
gdouble ncm_powspec_corr3d_eval_xi_lnr (NcmPowspecCorr3d *psc
,const gdouble z
,const gdouble lnr
);
Evaluates the function $\xi(z, r)$ at lnr
and z
.
ncm_powspec_corr3d_eval_xi ()
gdouble ncm_powspec_corr3d_eval_xi (NcmPowspecCorr3d *psc
,const gdouble z
,const gdouble r
);
Evaluate the function $\xi(z, r)$ at r
and z
.
Property Details
The “lnr0”
property
“lnr0” double
The Center value for $\ln(r)$.
Owner: NcmPowspecCorr3d
Flags: Read / Write
Default value: 0
The “powerspectrum”
property
“powerspectrum” NcmPowspec *
The NcmPowspec object to be transformed into $\xi(r, z)$.
Owner: NcmPowspecCorr3d
Flags: Read / Write / Construct Only
The “reltol”
property
“reltol” double
The relative tolerance for calibration in the distance direction.
Owner: NcmPowspecCorr3d
Flags: Read / Write / Construct
Allowed values: [2.22045e-16,1]
Default value: 0.001
The “reltol-z”
property
“reltol-z” double
The relative tolerance for calibration in the redshift direction.
Owner: NcmPowspecCorr3d
Flags: Read / Write / Construct
Allowed values: [2.22045e-16,1]
Default value: 1e-06
The “zf”
property
“zf” double
The output final time $z_f$ of the correlation function, $\xi(r,z)$.
Owner: NcmPowspecCorr3d
Flags: Read / Write
Default value: 1