__author__ = "sibirrer"
# this file contains a class to compute the Navaro-Frank-White function in mass/kappa space
# the potential therefore is its integral
import numpy as np
from lenstronomy.LensModel.Profiles.cnfw import CNFW
import lenstronomy.Util.param_util as param_util
from lenstronomy.LensModel.Profiles.base_profile import LensProfileBase
__all__ = ["CNFW_ELLIPSE"]
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class CNFW_ELLIPSE(LensProfileBase):
"""This class contains functions concerning the NFW profile.
relation are: R_200 = c * Rs
"""
param_names = ["Rs", "alpha_Rs", "r_core", "e1", "e2", "center_x", "center_y"]
lower_limit_default = {
"Rs": 0,
"alpha_Rs": 0,
"r_core": 0,
"e1": -0.5,
"e2": -0.5,
"center_x": -100,
"center_y": -100,
}
upper_limit_default = {
"Rs": 100,
"alpha_Rs": 10,
"r_core": 100,
"e1": 0.5,
"e2": 0.5,
"center_x": 100,
"center_y": 100,
}
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def __init__(self):
self.cnfw = CNFW()
self._diff = 0.0000000001
super(CNFW_ELLIPSE, self).__init__()
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def function(self, x, y, Rs, alpha_Rs, r_core, e1, e2, center_x=0, center_y=0):
"""Returns double integral of NFW profile."""
phi_G, q = param_util.ellipticity2phi_q(e1, e2)
x_shift = x - center_x
y_shift = y - center_y
cos_phi = np.cos(phi_G)
sin_phi = np.sin(phi_G)
e = min(abs(1.0 - q), 0.99)
xt1 = (cos_phi * x_shift + sin_phi * y_shift) * np.sqrt(1 - e)
xt2 = (-sin_phi * x_shift + cos_phi * y_shift) * np.sqrt(1 + e)
R_ = np.sqrt(xt1**2 + xt2**2)
f_ = self.cnfw.function(R_, 0, Rs, alpha_Rs, r_core, center_x=0, center_y=0)
return f_
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def derivatives(self, x, y, Rs, alpha_Rs, r_core, e1, e2, center_x=0, center_y=0):
"""Returns df/dx and df/dy of the function (integral of NFW)"""
phi_G, q = param_util.ellipticity2phi_q(e1, e2)
x_shift = x - center_x
y_shift = y - center_y
cos_phi = np.cos(phi_G)
sin_phi = np.sin(phi_G)
e = min(abs(1.0 - q), 0.99)
xt1 = (cos_phi * x_shift + sin_phi * y_shift) * np.sqrt(1 - e)
xt2 = (-sin_phi * x_shift + cos_phi * y_shift) * np.sqrt(1 + e)
f_x_prim, f_y_prim = self.cnfw.derivatives(
xt1, xt2, Rs, alpha_Rs, r_core, center_x=0, center_y=0
)
f_x_prim *= np.sqrt(1 - e)
f_y_prim *= np.sqrt(1 + e)
f_x = cos_phi * f_x_prim - sin_phi * f_y_prim
f_y = sin_phi * f_x_prim + cos_phi * f_y_prim
return f_x, f_y
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def hessian(self, x, y, Rs, alpha_Rs, r_core, e1, e2, center_x=0, center_y=0):
"""Returns Hessian matrix of function d^2f/dx^2, d^f/dy^2, d^2/dxdy."""
diff = 0.0000001
alpha_ra_dx, alpha_dec_dx = self.derivatives(
x + diff, y, Rs, alpha_Rs, r_core, e1, e2, center_x, center_y
)
alpha_ra_dy, alpha_dec_dy = self.derivatives(
x, y + diff, Rs, alpha_Rs, r_core, e1, e2, center_x, center_y
)
alpha_ra_dx_, alpha_dec_dx_ = self.derivatives(
x - diff, y, Rs, alpha_Rs, r_core, e1, e2, center_x, center_y
)
alpha_ra_dy_, alpha_dec_dy_ = self.derivatives(
x, y - diff, Rs, alpha_Rs, r_core, e1, e2, center_x, center_y
)
dalpha_rara = (alpha_ra_dx - alpha_ra_dx_) / diff / 2
dalpha_radec = (alpha_ra_dy - alpha_ra_dy_) / diff / 2
dalpha_decra = (alpha_dec_dx - alpha_dec_dx_) / diff / 2
dalpha_decdec = (alpha_dec_dy - alpha_dec_dy_) / diff / 2
f_xx = dalpha_rara
f_yy = dalpha_decdec
f_xy = dalpha_radec
f_yx = dalpha_decra
return f_xx, f_xy, f_yx, f_yy
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def mass_3d_lens(self, R, Rs, alpha_Rs, r_core, e1=0, e2=0):
"""Mass enclosed a 3d sphere or radius r given a lens parameterization with
angular units.
:return:
"""
return self.cnfw.mass_3d_lens(R, Rs, alpha_Rs, r_core)
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def density_lens(self, R, Rs, alpha_Rs, r_core, e1=0, e2=0):
"""Computes the density at 3d radius r given lens model parameterization.
The integral in the LOS projection of this quantity results in the convergence
quantity.
"""
return self.cnfw.density_lens(R, Rs, alpha_Rs, r_core)