Example #1
0
def test_background():

    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    kT_sim = 1.0
    Z_sim = 0.0
    norm_sim = 4.0e-2
    nH_sim = 0.04
    redshift = 0.01

    exp_time = (200., "ks")
    area = (1000., "cm**2")

    wcs = create_dummy_wcs()

    abs_model = WabsModel(nH_sim)

    events = EventList.create_empty_list(exp_time, area, wcs)

    spec_model = TableApecModel(0.05, 12.0, 5000, thermal_broad=False)
    spec = spec_model.return_spectrum(kT_sim, Z_sim, redshift, norm_sim)

    new_events = events.add_background(spec_model.ebins, spec, prng=prng,
                                       absorb_model=abs_model)

    new_events = ACIS_I(new_events, rebin=False, convolve_psf=False, prng=prng)

    new_events.write_spectrum("background_evt.pi", clobber=True)

    os.system("cp %s ." % new_events.parameters["ARF"])
    os.system("cp %s ." % new_events.parameters["RMF"])

    load_user_model(mymodel, "wapec")
    add_user_pars("wapec", ["nH", "kT", "metallicity", "redshift", "norm"],
                  [0.01, 4.0, 0.2, redshift, norm_sim*0.8],
                  parmins=[0.0, 0.1, 0.0, -20.0, 0.0],
                  parmaxs=[10.0, 20.0, 10.0, 20.0, 1.0e9],
                  parfrozen=[False, False, False, True, False])

    load_pha("background_evt.pi")
    set_stat("cstat")
    set_method("simplex")
    ignore(":0.5, 8.0:")
    set_model("wapec")
    fit()
    set_covar_opt("sigma", 1.6)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0]-nH_sim) < res.parmaxes[0]
    assert np.abs(res.parvals[1]-kT_sim) < res.parmaxes[1]
    assert np.abs(res.parvals[2]-Z_sim) < res.parmaxes[2]
    assert np.abs(res.parvals[3]-norm_sim) < res.parmaxes[3]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #2
0
def test_point_source():

    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    nH_sim = 0.02
    norm_sim = 1.0e-4
    alpha_sim = 0.95
    redshift = 0.02

    exp_time = (100., "ks")
    area = (3000., "cm**2")

    wcs = create_dummy_wcs()

    ebins = np.linspace(0.1, 11.5, 2001)
    emid = 0.5*(ebins[1:]+ebins[:-1])
    spec = norm_sim*(emid*(1.0+redshift))**(-alpha_sim)
    de = np.diff(ebins)[0]

    abs_model = TBabsModel(nH_sim)

    events = EventList.create_empty_list(exp_time, area, wcs)

    positions = [(30.01, 45.0)]

    new_events = events.add_point_sources(positions, ebins, spec, prng=prng,
                                          absorb_model=abs_model)

    new_events = ACIS_S(new_events, prng=prng)

    scalex = float(np.std(new_events['xpix'])*sigma_to_fwhm*new_events.parameters["dtheta"])
    scaley = float(np.std(new_events['ypix'])*sigma_to_fwhm*new_events.parameters["dtheta"])

    psf_scale = ACIS_S.psf_scale

    assert (scalex - psf_scale)/psf_scale < 0.01
    assert (scaley - psf_scale)/psf_scale < 0.01

    new_events.write_spectrum("point_source_evt.pi", clobber=True)

    os.system("cp %s ." % new_events.parameters["ARF"])
    os.system("cp %s ." % new_events.parameters["RMF"])

    load_user_model(mymodel, "tplaw")
    add_user_pars("tplaw", ["nH", "norm", "redshift", "alpha"],
                  [0.01, norm_sim*0.8, redshift, 0.9],
                  parmins=[0.0, 0.0, 0.0, 0.1],
                  parmaxs=[10.0, 1.0e9, 10.0, 10.0],
                  parfrozen=[False, False, True, False])

    load_pha("point_source_evt.pi")
    set_stat("cstat")
    set_method("simplex")
    ignore(":0.5, 9.0:")
    set_model("tplaw")
    fit()
    set_covar_opt("sigma", 1.6)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0]-nH_sim) < res.parmaxes[0]
    assert np.abs(res.parvals[1]-norm_sim/de) < res.parmaxes[1]
    assert np.abs(res.parvals[2]-alpha_sim) < res.parmaxes[2]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #3
0
def boxbod_func(pars, x):
    b1, b2 = pars
    return BoxBOD.model(x, b1, b2)

ui.load_user_model(boxbod_func, "boxbod")
ui.add_user_pars("boxbod", ["b1", "b2"])
bb = boxbod
ui.set_model(bb)
bb.b1, bb.b2 = BoxBOD.p0[0], BoxBOD.p0[1]

# Perform fit
ui.set_stat('chi2datavar')
#ui.set_method('levmar') #  ['levmar', 'moncar', 'neldermead', 'simplex']
ui.set_method_opt('xtol', 1e-10)
ui.fit() # Compute best-fit parameters
ui.set_covar_opt('eps', 1e-5) # @todo: Why does this parameter have no effect
ui.covariance() # Compute covariance matrix (i.e. errors)
#ui.conf() # Compute profile errors
#ui.show_all() # Print a very nice summary of your session to less

# Report results
fr = ui.get_fit_results()
cr = ui.get_covar_results()

# Report results (we have to apply the s factor ourselves)
popt = np.array(fr.parvals)
chi2 = fr.statval
s_factor = np.sqrt(chi2 / fr.dof)
perr = s_factor * np.array(cr.parmaxes)
report_results('sherpa', popt, perr, chi2)
Example #4
0
def do_beta_model(source, v_field, em_field):

    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    ds = source.ds

    A = 3000.
    exp_time = 1.0e5
    redshift = 0.05
    nH_sim = 0.02

    apec_model = TableApecModel(0.1, 11.5, 20000, thermal_broad=False)
    abs_model = TBabsModel(nH_sim)

    sphere = ds.sphere("c", (0.5, "Mpc"))

    kT_sim = source.kT
    Z_sim = source.Z

    thermal_model = ThermalSourceModel(apec_model,
                                       Zmet=Z_sim,
                                       prng=source.prng)
    photons = PhotonList.from_data_source(sphere, redshift, A, exp_time,
                                          thermal_model)

    D_A = photons.parameters["FiducialAngularDiameterDistance"]

    norm_sim = sphere.quantities.total_quantity(em_field)
    norm_sim *= 1.0e-14 / (4 * np.pi * D_A * D_A * (1. + redshift) *
                           (1. + redshift))
    norm_sim = float(norm_sim.in_cgs())

    v1, v2 = sphere.quantities.weighted_variance(v_field, em_field)
    sigma_sim = float(v1.in_units("km/s"))
    mu_sim = -float(v2.in_units("km/s"))

    events = photons.project_photons("z",
                                     absorb_model=abs_model,
                                     prng=source.prng)
    events = ACIS_I(events, rebin=False, convolve_psf=False, prng=source.prng)

    events.write_spectrum("beta_model_evt.pi", clobber=True)

    os.system("cp %s ." % events.parameters["ARF"])
    os.system("cp %s ." % events.parameters["RMF"])

    load_user_model(mymodel, "tbapec")
    add_user_pars("tbapec", ["nH", "kT", "metallicity", "redshift", "norm"],
                  [0.01, 4.0, 0.2, redshift, norm_sim * 0.8],
                  parmins=[0.0, 0.1, 0.0, -20.0, 0.0],
                  parmaxs=[10.0, 20.0, 10.0, 20.0, 1.0e9],
                  parfrozen=[False, False, False, True, False])

    load_pha("beta_model_evt.pi")
    set_stat("cstat")
    set_method("simplex")
    ignore(":0.5, 8.0:")
    set_model("tbapec")
    fit()
    set_covar_opt("sigma", 1.645)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0] - nH_sim) < res.parmaxes[0]
    assert np.abs(res.parvals[1] - kT_sim) < res.parmaxes[1]
    assert np.abs(res.parvals[2] - Z_sim) < res.parmaxes[2]
    assert np.abs(res.parvals[3] - norm_sim) < res.parmaxes[3]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #5
0
# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Compute results with Sherpa"""
from __future__ import print_function, division
# __doctest_skip__
__doctest_skip__ = ['*']
import numpy as np
import sherpa.astro.ui as sau

sau.load_data('counts.fits.gz')
sau.set_source('normgauss2d.source + const2d.background')
sau.set_stat('cstat')
# Ask for high-precision results
sau.set_method_opt('ftol', 1e-20)
sau.set_covar_opt('eps', 1e-20)

# Set start parameters close to simulation values to make the fit converge
sau.set_par('source.xpos', 101)
sau.set_par('source.ypos', 101)
sau.set_par('source.ampl', 1.1e3)
sau.set_par('source.fwhm', 10)
sau.set_par('background.c0', 1.1)

# Run fit and covariance estimation
# Results are automatically printed to the screen
sau.fit()
sau.covar()

# Sherpa uses fwhm instead of sigma as extension parameter ... need to convert
# http://cxc.harvard.edu/sherpa/ahelp/gauss2d.html
fwhm_to_sigma = 1. / np.sqrt(8 * np.log(2))
cov = sau.get_covar_results()
Example #6
0
def plaw_fit(alpha_sim):

    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    nH_sim = 0.02
    norm_sim = 1.0e-4
    redshift = 0.01

    exp_time = 5.0e4
    area = 40000.0
    inst_name = "hdxi"

    spec = Spectrum.from_powerlaw(alpha_sim, redshift, norm_sim)
    spec.apply_foreground_absorption(nH_sim)
    e = spec.generate_energies(exp_time, area)

    pt_src = PointSourceModel(30.0, 45.0, e.size)

    write_photon_list("plaw_model",
                      "plaw_model",
                      e.flux,
                      pt_src.ra,
                      pt_src.dec,
                      e,
                      clobber=True)

    instrument_simulator("plaw_model_simput.fits",
                         "plaw_model_evt.fits",
                         exp_time,
                         inst_name, [30.0, 45.0],
                         astro_bkgnd=None,
                         instr_bkgnd_scale=0.0)

    inst = get_instrument_from_registry(inst_name)
    arf = AuxiliaryResponseFile(inst["arf"])
    rmf = RedistributionMatrixFile(inst["rmf"])
    os.system("cp %s ." % arf.filename)
    os.system("cp %s ." % rmf.filename)

    write_spectrum("plaw_model_evt.fits", "plaw_model_evt.pha", clobber=True)

    load_user_model(mymodel, "wplaw")
    add_user_pars("wplaw", ["nH", "norm", "redshift", "alpha"],
                  [0.01, norm_sim * 0.8, redshift, 0.9],
                  parmins=[0.0, 0.0, 0.0, 0.1],
                  parmaxs=[10.0, 1.0e9, 10.0, 10.0],
                  parfrozen=[False, False, True, False])

    load_pha("plaw_model_evt.pha")
    set_stat("cstat")
    set_method("simplex")
    ignore(":0.5, 9.0:")
    set_model("wplaw")
    fit()
    set_covar_opt("sigma", 1.645)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0] - nH_sim) < res.parmaxes[0]
    assert np.abs(res.parvals[1] - norm_sim) < res.parmaxes[1]
    assert np.abs(res.parvals[2] - alpha_sim) < res.parmaxes[2]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #7
0
def test_annulus():

    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    r_in = 10.0
    r_out = 30.0

    e = spec.generate_energies(exp_time, area, prng=prng)

    ann_src = AnnulusModel(ra0, dec0, r_in, r_out, e.size, prng=prng)

    write_photon_list("ann",
                      "ann",
                      e.flux,
                      ann_src.ra,
                      ann_src.dec,
                      e,
                      overwrite=True)

    instrument_simulator("ann_simput.fits",
                         "ann_evt.fits",
                         exp_time,
                         "hdxi", [ra0, dec0],
                         ptsrc_bkgnd=False,
                         instr_bkgnd=False,
                         foreground=False,
                         prng=prng)

    inst = get_instrument_from_registry("hdxi")
    arf = AuxiliaryResponseFile(inst["arf"])
    cspec = ConvolvedSpectrum(spec, arf)
    ph_flux = cspec.get_flux_in_band(0.5, 7.0)[0].value
    S0 = ph_flux / (np.pi * (r_out**2 - r_in**2))

    write_radial_profile("ann_evt.fits",
                         "ann_evt_profile.fits", [ra0, dec0],
                         1.1 * r_in,
                         0.9 * r_out,
                         100,
                         ctr_type="celestial",
                         emin=0.5,
                         emax=7.0,
                         overwrite=True)

    load_data(1, "ann_evt_profile.fits", 3, ["RMID", "SUR_BRI", "SUR_BRI_ERR"])
    set_stat("chi2")
    set_method("levmar")
    set_source("const1d.src")
    src.c0 = 0.8 * S0

    fit()
    set_covar_opt("sigma", 1.645)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0] - S0) < res.parmaxes[0]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #8
0
def test_beta_model_flux():
    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    r_c = 20.0
    beta = 1.0

    prng = 34

    e = spec.generate_energies(exp_time, area, prng=prng)

    beta_src = BetaModel(ra0, dec0, r_c, beta, e.size, prng=prng)

    write_photon_list("beta",
                      "beta",
                      e.flux,
                      beta_src.ra,
                      beta_src.dec,
                      e,
                      overwrite=True)

    instrument_simulator("beta_simput.fits",
                         "beta_evt.fits",
                         exp_time,
                         "acisi_cy0", [ra0, dec0],
                         ptsrc_bkgnd=False,
                         instr_bkgnd=False,
                         foreground=False,
                         roll_angle=37.0,
                         prng=prng)

    ph_flux = spec.get_flux_in_band(0.5, 7.0)[0].value
    S0 = 3.0 * ph_flux / (2.0 * np.pi * r_c * r_c)

    wspec = spec.new_spec_from_band(0.5, 7.0)

    make_exposure_map("beta_evt.fits",
                      "beta_expmap.fits",
                      wspec.emid.value,
                      weights=wspec.flux.value,
                      overwrite=True)

    write_radial_profile("beta_evt.fits",
                         "beta_evt_profile.fits", [ra0, dec0],
                         0.0,
                         100.0,
                         200,
                         ctr_type="celestial",
                         emin=0.5,
                         emax=7.0,
                         expmap_file="beta_expmap.fits",
                         overwrite=True)

    load_data(1, "beta_evt_profile.fits", 3,
              ["RMID", "SUR_FLUX", "SUR_FLUX_ERR"])
    set_stat("chi2")
    set_method("levmar")
    set_source("beta1d.src")
    src.beta = 1.0
    src.r0 = 10.0
    src.ampl = 0.8 * S0
    freeze(src.xpos)

    fit()
    set_covar_opt("sigma", 1.645)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0] - r_c) < res.parmaxes[0]
    assert np.abs(res.parvals[1] - beta) < res.parmaxes[1]
    assert np.abs(res.parvals[2] - S0) < res.parmaxes[2]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #9
0
def test_beta_model():
    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    r_c = 20.0
    beta = 1.0

    exp_time = Quantity(500.0, "ks")

    e = spec.generate_energies(exp_time, area, prng=prng)

    beta_src = BetaModel(ra0, dec0, r_c, beta, e.size, prng=prng)

    write_photon_list("beta",
                      "beta",
                      e.flux,
                      beta_src.ra,
                      beta_src.dec,
                      e,
                      overwrite=True)

    instrument_simulator("beta_simput.fits",
                         "beta_evt.fits",
                         exp_time,
                         "hdxi", [ra0, dec0],
                         ptsrc_bkgnd=False,
                         instr_bkgnd=False,
                         foreground=False,
                         prng=prng)

    inst = get_instrument_from_registry("hdxi")
    arf = AuxiliaryResponseFile(inst["arf"])
    cspec = ConvolvedSpectrum(spec, arf)
    ph_flux = cspec.get_flux_in_band(0.5, 7.0)[0].value
    S0 = 3.0 * ph_flux / (2.0 * np.pi * r_c * r_c)

    write_radial_profile("beta_evt.fits",
                         "beta_evt_profile.fits", [ra0, dec0],
                         0.0,
                         100.0,
                         200,
                         ctr_type="celestial",
                         emin=0.5,
                         emax=7.0,
                         overwrite=True)

    load_data(1, "beta_evt_profile.fits", 3,
              ["RMID", "SUR_BRI", "SUR_BRI_ERR"])
    set_stat("chi2")
    set_method("levmar")
    set_source("beta1d.src")
    src.beta = 1.0
    src.r0 = 10.0
    src.ampl = 0.8 * S0
    freeze(src.xpos)

    fit()
    set_covar_opt("sigma", 1.645)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0] - r_c) < res.parmaxes[0]
    assert np.abs(res.parvals[1] - beta) < res.parmaxes[1]
    assert np.abs(res.parvals[2] - S0) < res.parmaxes[2]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #10
0
def plaw_fit(alpha_sim):

    tmpdir = tempfile.mkdtemp()
    curdir = os.getcwd()
    os.chdir(tmpdir)

    bms = BetaModelSource()
    ds = bms.ds

    def _hard_emission(field, data):
        return YTQuantity(1.0e-18, "s**-1*keV**-1")*data["density"]*data["cell_volume"]/mp
    ds.add_field(("gas", "hard_emission"), function=_hard_emission, units="keV**-1*s**-1")

    nH_sim = 0.02
    abs_model = WabsModel(nH_sim)

    A = YTQuantity(2000., "cm**2")
    exp_time = YTQuantity(2.0e5, "s")
    redshift = 0.01

    sphere = ds.sphere("c", (100.,"kpc"))

    plaw_model = PowerLawSourceModel(1.0, 0.01, 11.0, "hard_emission", 
                                     alpha_sim, prng=prng)

    photons = PhotonList.from_data_source(sphere, redshift, A, exp_time,
                                          plaw_model)

    D_A = photons.parameters["FiducialAngularDiameterDistance"]
    dist_fac = 1.0/(4.*np.pi*D_A*D_A*(1.+redshift)**3).in_cgs()
    norm_sim = float((sphere["hard_emission"]).sum()*dist_fac.in_cgs())*(1.+redshift)

    events = photons.project_photons("z", absorb_model=abs_model,
                                     prng=bms.prng,
                                     no_shifting=True)
    events = ACIS_I(events, rebin=False, convolve_psf=False, prng=bms.prng)
    events.write_spectrum("plaw_model_evt.pi", clobber=True)

    os.system("cp %s ." % events.parameters["ARF"])
    os.system("cp %s ." % events.parameters["RMF"])

    load_user_model(mymodel, "wplaw")
    add_user_pars("wplaw", ["nH", "norm", "redshift", "alpha"],
                  [0.01, norm_sim*1.1, redshift, 0.9], 
                  parmins=[0.0, 0.0, 0.0, 0.1],
                  parmaxs=[10.0, 1.0e9, 10.0, 10.0],
                  parfrozen=[False, False, True, False])

    load_pha("plaw_model_evt.pi")
    set_stat("cstat")
    set_method("simplex")
    ignore(":0.6, 7.0:")
    set_model("wplaw")
    fit()
    set_covar_opt("sigma", 1.645)
    covar()
    res = get_covar_results()

    assert np.abs(res.parvals[0]-nH_sim) < res.parmaxes[0]
    assert np.abs(res.parvals[1]-norm_sim) < res.parmaxes[1]
    assert np.abs(res.parvals[2]-alpha_sim) < res.parmaxes[2]

    os.chdir(curdir)
    shutil.rmtree(tmpdir)
Example #11
0
# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Compute results with Sherpa"""

import numpy as np
import sherpa.astro.ui as sau

sau.load_data('counts.fits.gz')
sau.set_source('normgauss2d.source + const2d.background')
sau.set_stat('cstat')
# Ask for high-precision results
sau.set_method_opt('ftol', 1e-20)
sau.set_covar_opt('eps', 1e-20)

# Set start parameters close to simulation values to make the fit converge
sau.set_par('source.xpos', 101)
sau.set_par('source.ypos', 101)
sau.set_par('source.ampl', 1.1e3)
sau.set_par('source.fwhm', 10)
sau.set_par('background.c0', 1.1)

# Run fit and covariance estimation
# Results are automatically printed to the screen
sau.fit()
sau.covar()

# Sherpa uses fwhm instead of sigma as extension parameter ... need to convert
# http://cxc.harvard.edu/sherpa/ahelp/gauss2d.html
fwhm_to_sigma = 1. / np.sqrt(8 * np.log(2))
cov = sau.get_covar_results()
sigma = fwhm_to_sigma * cov.parvals[0]
sigma_err = fwhm_to_sigma * cov.parmaxes[0]
Example #12
0
# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Compute results with Sherpa"""
from __future__ import print_function, division
import numpy as np
import sherpa.astro.ui as sau

sau.load_data("counts.fits.gz")
sau.set_source("normgauss2d.source + const2d.background")
sau.set_stat("cstat")
# Ask for high-precision results
sau.set_method_opt("ftol", 1e-20)
sau.set_covar_opt("eps", 1e-20)

# Set start parameters close to simulation values to make the fit converge
sau.set_par("source.xpos", 101)
sau.set_par("source.ypos", 101)
sau.set_par("source.ampl", 1.1e3)
sau.set_par("source.fwhm", 10)
sau.set_par("background.c0", 1.1)

# Run fit and covariance estimation
# Results are automatically printed to the screen
sau.fit()
sau.covar()

# Sherpa uses fwhm instead of sigma as extension parameter ... need to convert
# http://cxc.harvard.edu/sherpa/ahelp/gauss2d.html
fwhm_to_sigma = 1.0 / np.sqrt(8 * np.log(2))
cov = sau.get_covar_results()
sigma = fwhm_to_sigma * cov.parvals[0]
sigma_err = fwhm_to_sigma * cov.parmaxes[0]