xlens.simulator.perturbation.zslice

Constant-shear perturbation applied per redshift slice.

Classes

ShearRedshift

Constant shear in each redshift slice.

Module Contents

class ShearRedshift(z_bounds, mode, g_dist='g1', shear_value=0.02, kappa_value=0.0)

Bases: object

Constant shear in each redshift slice.

The shear pattern across redshift bins is encoded as a ternary integer (mode), where each base-3 digit maps to -shear_value, +shear_value, or 0.0.

Parameters:

• z_bounds (list[float]) – Redshift bin boundaries (length nz_bins + 1).

• mode (int) – Ternary-encoded shear assignment (see class docstring).

• g_dist ({'g1', 'g2'}) – Which shear component receives the test signal.

• shear_value (float) – Absolute shear amplitude per bin.

• kappa_value (float) – Constant convergence applied to all bins.

nz_bins

code

z_bounds

g_dist = 'g1'

shear_value = 0.02

shear_list

kappa = 0.0

determine_shear_list(code)

Convert a ternary code string into a list of shear values.

_get_zshear(redshift)

Return the shear value for a galaxy at the given redshift.

get_shear(redshift)

Return (g1, g2, mu, gamma1, gamma2) for a given redshift.

distort_galaxy(src)

This function distorts the galaxy’s shape and position :param src (np.array): :type src (np.array): row of structured array

Return type:

distorted galaxy position and lensing distortions