xlens.simulator.perturbation.lognormal_flat

Log-normal convergence and shear field on a flat sky.

Classes

ShearLogNormalFlat

Flat-sky log-normal shear field generated from a CCL weak-lensing

Module Contents

class ShearLogNormalFlat(z_source, field_size_deg=5.0, npix=2048, seed=None)[source]

Flat-sky log-normal shear field generated from a CCL weak-lensing power spectrum.

The constructor computes kappa, gamma1, and gamma2 maps and builds bivariate spline interpolators so that distort_galaxy can evaluate the lensing fields at arbitrary sky positions.

Parameters:

z_source (float) – Source redshift for the weak-lensing tracer.
field_size_deg (float, optional) – Side length of the square field in degrees.
npix (int, optional) – Number of pixels per side used for the Fourier-space generation.
seed (int or None, optional) – Random seed for reproducible field realisations.

cosmo[source]

z_source[source]

field_size_deg = 5.0[source]

npix = 2048[source]

seed = None[source]

ell[source]

cl_kappa[source]

kappa_G_map[source]

kappa_LN_map[source]

gamma1_map[source]

gamma2_map[source]

kappa_map[source]

kappa_interp[source]

gamma1_interp[source]

gamma2_interp[source]

distort_galaxy(src)[source]

Return lensing distortions interpolated at the galaxy position.

Parameters:: src (numpy structured scalar) – Row with "dx" and "dy" fields (arcseconds).
Returns:: Standard shear result dict (see _get_shear_res_dict()).
Return type:: dict