Source code for lenstronomy.Analysis.light2mass

import numpy as np
from lenstronomy.Util import util
from lenstronomy.LightModel.light_model import LightModel

__all__ = ['light2mass_interpol']


[docs]def light2mass_interpol(lens_light_model_list, kwargs_lens_light, numPix=100, deltaPix=0.05, subgrid_res=5, center_x=0, center_y=0): """ takes a lens light model and turns it numerically in a lens model (with all lensmodel quantities computed on a grid). Then provides an interpolated grid for the quantities. :param kwargs_lens_light: lens light keyword argument list :param numPix: number of pixels per axis for the return interpolation :param deltaPix: interpolation/pixel size :param center_x: center of the grid :param center_y: center of the grid :param subgrid_res: subgrid for the numerical integrals :return: keyword arguments for 'INTERPOL' lens model """ # make super-sampled grid x_grid_sub, y_grid_sub = util.make_grid(numPix=numPix * 5, deltapix=deltaPix, subgrid_res=subgrid_res) import lenstronomy.Util.mask_util as mask_util mask = mask_util.mask_azimuthal(x_grid_sub, y_grid_sub, center_x, center_y, r=1) x_grid, y_grid = util.make_grid(numPix=numPix, deltapix=deltaPix) # compute light on the subgrid lightModel = LightModel(light_model_list=lens_light_model_list) flux = lightModel.surface_brightness(x_grid_sub, y_grid_sub, kwargs_lens_light) flux_norm = np.sum(flux[mask == 1]) / np.sum(mask) flux /= flux_norm from lenstronomy.LensModel import convergence_integrals as integral # compute lensing quantities with subgrid convergence_sub = util.array2image(flux) f_x_sub, f_y_sub = integral.deflection_from_kappa_grid(convergence_sub, grid_spacing=deltaPix / float(subgrid_res)) f_sub = integral.potential_from_kappa_grid(convergence_sub, grid_spacing=deltaPix / float(subgrid_res)) # interpolation function on lensing quantities x_axes_sub, y_axes_sub = util.get_axes(x_grid_sub, y_grid_sub) from lenstronomy.LensModel.Profiles.interpol import Interpol interp_func = Interpol() interp_func.do_interp(x_axes_sub, y_axes_sub, f_sub, f_x_sub, f_y_sub) # compute lensing quantities on sparser grid x_axes, y_axes = util.get_axes(x_grid, y_grid) f_ = interp_func.function(x_grid, y_grid) f_x, f_y = interp_func.derivatives(x_grid, y_grid) # numerical differentials for second order differentials from lenstronomy.LensModel.lens_model import LensModel lens_model = LensModel(lens_model_list=['INTERPOL']) kwargs = [{'grid_interp_x': x_axes_sub, 'grid_interp_y': y_axes_sub, 'f_': f_sub, 'f_x': f_x_sub, 'f_y': f_y_sub}] f_xx, f_xy, f_yx, f_yy = lens_model.hessian(x_grid, y_grid, kwargs, diff=0.00001) kwargs_interpol = {'grid_interp_x': x_axes, 'grid_interp_y': y_axes, 'f_': util.array2image(f_), 'f_x': util.array2image(f_x), 'f_y': util.array2image(f_y), 'f_xx': util.array2image(f_xx), 'f_xy': util.array2image(f_xy), 'f_yy': util.array2image(f_yy)} return kwargs_interpol