Source code for lenstronomy.LensModel.Profiles.dipole

__author__ = 'sibirrer'


import numpy as np
from lenstronomy.LensModel.Profiles.base_profile import LensProfileBase

__all__ = ['Dipole', 'DipoleUtil']


[docs]class Dipole(LensProfileBase): """ class for dipole response of two massive bodies (experimental) """ param_names = ['com_x', 'com_y', 'phi_dipole', 'coupling'] lower_limit_default = {'com_x': -100, 'com_y': -100, 'phi_dipole': -10, 'coupling': -10} upper_limit_default = {'com_x': 100, 'com_y': 100, 'phi_dipole': 10, 'coupling': 10}
[docs] def function(self, x, y, com_x, com_y, phi_dipole, coupling): # coordinate shift x_shift = x - com_x y_shift = y - com_y # rotation angle sin_phi = np.sin(phi_dipole) cos_phi = np.cos(phi_dipole) x_ = cos_phi*x_shift + sin_phi*y_shift y_ = -sin_phi*x_shift + cos_phi*y_shift r = np.sqrt(x_**2 + y_**2) # f_ = coupling**2 * (x_/y_)**2 # np.sqrt(np.abs(y_)/r) * np.abs(y_) # f_ = coupling * np.abs(x_) f_ = np.zeros_like(x_) return f_
[docs] def derivatives(self, x, y, com_x, com_y, phi_dipole, coupling): # coordinate shift x_shift = x - com_x y_shift = y - com_y # rotation angle sin_phi = np.sin(phi_dipole) cos_phi = np.cos(phi_dipole) x_ = cos_phi*x_shift + sin_phi*y_shift y_ = -sin_phi*x_shift + cos_phi*y_shift f_x_prim = coupling * x_/np.sqrt(x_**2 + y_**2) f_y_prim = np.zeros_like(x_) # rotate back 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
[docs] def hessian(self, x, y, com_x, com_y, phi_dipole, coupling): # coordinate shift x_shift = x - com_x y_shift = y - com_y # rotation angle sin_phi = np.sin(phi_dipole) cos_phi = np.cos(phi_dipole) x_ = cos_phi*x_shift + sin_phi*y_shift y_ = -sin_phi*x_shift + cos_phi*y_shift r = np.sqrt(x_**2 + y_**2) f_xx_prim = coupling*y_**2/r**3 f_xy_prim = -coupling * x_ * y_ / r**3 f_yy_prim = np.zeros_like(x_) kappa = 1./2 * (f_xx_prim + f_yy_prim) gamma1_value = 1./2 * (f_xx_prim - f_yy_prim) gamma2_value = f_xy_prim # rotate back gamma1 = np.cos(2*phi_dipole)*gamma1_value-np.sin(2*phi_dipole)*gamma2_value gamma2 = +np.sin(2*phi_dipole)*gamma1_value+np.cos(2*phi_dipole)*gamma2_value f_xx = kappa + gamma1 f_yy = kappa - gamma1 f_xy = gamma2 return f_xx, f_xy, f_xy, f_yy
[docs]class DipoleUtil(object): """ pre-calculation of dipole properties """
[docs] def com(self, center1_x, center1_y, center2_x, center2_y, Fm): """ :return: center of mass """ com_x = (Fm * center1_x + center2_x)/(Fm + 1.) com_y = (Fm * center1_y + center2_y)/(Fm + 1.) return com_x, com_y
[docs] def mass_ratio(self, theta_E, theta_E_sub): """ computes mass ration of the two clumps with given Einstein radius and power law slope (clump1/sub-clump) :param theta_E: :param theta_E_sub: :return: """ return (theta_E / theta_E_sub) ** 2
[docs] def angle(self, center1_x, center1_y, center2_x, center2_y): """ compute the rotation angle of the dipole :return: """ phi_G = np.arctan2(center2_y - center1_y, center2_x - center1_x) return phi_G