Skip to content

Commit

Permalink
Update tests for Chebychev + Legendre wavelength solutions
Browse files Browse the repository at this point in the history
  • Loading branch information
@dhomeier
dhomeier committed Dec 3, 2024
1 parent 685a7a7 commit 0a90cde
Showing 1 changed file with 44 additions and 13 deletions.
57 changes: 44 additions & 13 deletions specutils/tests/test_loaders.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -398,7 +398,8 @@ def test_iraf_linear(remote_data_path):
@pytest.mark.filterwarnings('ignore:non-ASCII characters are present in the FITS file header')
@remote_access([{'id': '3359180', 'filename': 'log-linear_fits_solution.fits'}])
def test_iraf_log_linear(remote_data_path):

"""Non-linear wavelength solution for DTYPE=1 (log-linear) encoded IRAF-style (not implemented).
"""
with pytest.raises(NotImplementedError):
assert Spectrum1D.read(remote_data_path, format='iraf')

Expand All @@ -407,44 +408,74 @@ def test_iraf_log_linear(remote_data_path):
@pytest.mark.filterwarnings('ignore:Read spectral axis of shape')
@remote_access([{'id': '3359190', 'filename': 'non-linear_fits_solution_cheb.fits'}])
def test_iraf_non_linear_chebyshev(remote_data_path):
chebyshev_model = models.Chebyshev1D(degree=2, domain=[1616, 3259])
"""Read non-linear wavelength solution for FTYPE=1 (Chebyshev series) encoded IRAF-style.
"""
chebyshev_model = models.Chebyshev1D(degree=2, domain=[1616.37, 3259.98])
chebyshev_model.c0.value = 5115.64008186
chebyshev_model.c1.value = 535.515983712
chebyshev_model.c2.value = -0.779265625182

wavelength_axis = chebyshev_model(range(1, 4097)) * u.angstrom

spectrum_1d = Spectrum1D.read(remote_data_path, format='iraf')

assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(wavelength_axis, spectrum_1d.wavelength)
assert_allclose(spectrum_1d.wavelength, wavelength_axis, rtol=1e-10)

# Read from HDUList
with fits.open(remote_data_path) as hdulist:
spectrum_1d = Spectrum1D.read(hdulist, format='iraf')
assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(wavelength_axis, spectrum_1d.wavelength)
assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(spectrum_1d.wavelength, wavelength_axis, rtol=1e-10)
assert_allclose(spectrum_1d.wavelength[[0, 1, -1]],
[3514.56625403, 3515.2291341, 6190.37186578] * u.angstrom, rtol=1e-10)

# Read pmin, pmax as integer values (standard interpretation pre #1196)
hdulist[0].header['WAT2_002'] = '.39 1. 0. 1 3 1616 3259 5115.64008185559 535.515983711607 -0.7'
chebyshev_model.domain = [1616, 3259]
wavelength_axis = chebyshev_model(range(1, 4097)) * u.angstrom

spectrum_1d = Spectrum1D.read(hdulist, format='iraf')
assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(spectrum_1d.wavelength, wavelength_axis, rtol=1e-10)
assert_allclose(spectrum_1d.wavelength[[0, 1, -1]],
[3514.41405321, 3515.07718045, 6191.20308524] * u.angstrom, rtol=1e-10)

@pytest.mark.filterwarnings('ignore:Flux unit was not provided')
@pytest.mark.filterwarnings('ignore:non-ASCII characters are present in the FITS file header')
@pytest.mark.filterwarnings('ignore:Read spectral axis of shape')
@remote_access([{'id': '3359194', 'filename': 'non-linear_fits_solution_legendre.fits'}])
def test_iraf_non_linear_legendre(remote_data_path):

legendre_model = models.Legendre1D(degree=3, domain=[21, 4048])
"""Read non-linear wavelength solution for FTYPE=2 (Legendre series) encoded IRAF-style.
"""
legendre_model = models.Legendre1D(degree=3, domain=[21.64, 4048.55])
legendre_model.c0.value = 5468.67555891
legendre_model.c1.value = 835.332144466
legendre_model.c2.value = -6.02202094803
legendre_model.c3.value = -1.13142953897

wavelength_axis = legendre_model(range(1, 4143)) * u.angstrom

spectrum_1d = Spectrum1D.read(remote_data_path, format='iraf')

assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(wavelength_axis, spectrum_1d.wavelength)
assert_allclose(spectrum_1d.wavelength, wavelength_axis, rtol=1e-10)

# Read from HDUList
with fits.open(remote_data_path) as hdulist:
spectrum_1d = Spectrum1D.read(hdulist, format='iraf')
assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(spectrum_1d.wavelength, wavelength_axis, rtol=1e-10)
assert_allclose(spectrum_1d.wavelength[[0, 1, -1]],
[4619.77414264, 4620.19462372, 6334.43272858] * u.angstrom, rtol=1e-10)

# Read pmin, pmax as integer values (standard interpretation pre #1196)
hdulist[0].header['WAT2_002'] = '.00 1. 0. 2 4 21 4048.00000000000 5468.67555890614 835.3321444656'
legendre_model.domain = [21, 4048]
wavelength_axis = legendre_model(range(1, 4143)) * u.angstrom

spectrum_1d = Spectrum1D.read(hdulist, format='iraf')
assert isinstance(spectrum_1d, Spectrum1D)
assert_allclose(spectrum_1d.wavelength, wavelength_axis, rtol=1e-10)
assert_allclose(spectrum_1d.wavelength[[0, 1, -1]],
[4620.04343851, 4620.46391004 , 6334.65282602] * u.angstrom, rtol=1e-10)

@pytest.mark.filterwarnings('ignore:non-ASCII characters are present in the FITS file header')
@remote_access([{'id': '3359196', 'filename': 'non-linear_fits_solution_linear-spline.fits'}])
Expand All @@ -466,7 +497,7 @@ def test_iraf_non_linear_cubic_spline(remote_data_path):
@pytest.mark.remote_data
def test_iraf_multispec_chebyshev():
"""Test loading of SpectrumCollection from IRAF MULTISPEC format FITS file -
nonlinear 2D WCS with Chebyshev solution (FTYPE=1).
nonlinear 2D WCS with Chebyshev solution (DTYPE=2, FTYPE=1).
"""
iraf_url = 'https://github.com/astropy/specutils/raw/legacy-specutils/specutils/io/tests/files'
# Read reference ASCII spectrum from remote file.
Expand All @@ -486,7 +517,7 @@ def test_iraf_multispec_chebyshev():
@pytest.mark.remote_data
def test_iraf_multispec_legendre():
"""Test loading of SpectrumCollection from IRAF MULTISPEC format FITS file -
nonlinear 2D WCS with Legendre solution (FTYPE=2).
nonlinear 2D WCS with Legendre solution (DTYPE=2, FTYPE=2).
"""
iraf_url = 'https://github.com/astropy/specutils/raw/legacy-specutils/specutils/io/tests/files'
# Read reference ASCII spectrum from remote file.
Expand Down

0 comments on commit 0a90cde

Please sign in to comment.