FEA-Bench / testbed /astropy__astropy /astropy /modeling /tests /test_functional_models.py
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# Licensed under a 3-clause BSD style license - see LICENSE.rst
import pytest
import numpy as np
from numpy.testing import assert_allclose, assert_array_equal, assert_array_less
from astropy.modeling import models, InputParameterError
from astropy.coordinates import Angle
from astropy.modeling import fitting
from astropy.tests.helper import catch_warnings
from astropy.utils.exceptions import AstropyDeprecationWarning
try:
from scipy import optimize # pylint: disable=W0611
HAS_SCIPY = True
except ImportError:
HAS_SCIPY = False
def test_sigma_constant():
"""
Test that the GAUSSIAN_SIGMA_TO_FWHM constant matches the
gaussian_sigma_to_fwhm constant in astropy.stats. We define
it manually in astropy.modeling to avoid importing from
astropy.stats.
"""
from astropy.stats.funcs import gaussian_sigma_to_fwhm
from astropy.modeling.functional_models import GAUSSIAN_SIGMA_TO_FWHM
assert gaussian_sigma_to_fwhm == GAUSSIAN_SIGMA_TO_FWHM
def test_Trapezoid1D():
"""Regression test for https://github.com/astropy/astropy/issues/1721"""
model = models.Trapezoid1D(amplitude=4.2, x_0=2.0, width=1.0, slope=3)
xx = np.linspace(0, 4, 8)
yy = model(xx)
yy_ref = [0., 1.41428571, 3.12857143, 4.2, 4.2, 3.12857143, 1.41428571, 0.]
assert_allclose(yy, yy_ref, rtol=0, atol=1e-6)
def test_Gaussian2D():
"""
Test rotated elliptical Gaussian2D model.
https://github.com/astropy/astropy/pull/2038
"""
model = models.Gaussian2D(4.2, 1.7, 3.1, x_stddev=5.1, y_stddev=3.3,
theta=np.pi/6.)
y, x = np.mgrid[0:5, 0:5]
g = model(x, y)
g_ref = [[3.01907812, 2.99051889, 2.81271552, 2.5119566, 2.13012709],
[3.55982239, 3.6086023, 3.4734158, 3.17454575, 2.75494838],
[3.88059142, 4.0257528, 3.96554926, 3.70908389, 3.29410187],
[3.91095768, 4.15212857, 4.18567526, 4.00652015, 3.64146544],
[3.6440466, 3.95922417, 4.08454159, 4.00113878, 3.72161094]]
assert_allclose(g, g_ref, rtol=0, atol=1e-6)
assert_allclose([model.x_fwhm, model.y_fwhm],
[12.009582229657841, 7.7709061486021325])
def test_Gaussian2DCovariance():
"""
Test rotated elliptical Gaussian2D model when cov_matrix is input.
https://github.com/astropy/astropy/pull/2199
"""
cov_matrix = [[49., -16.], [-16., 9.]]
model = models.Gaussian2D(17., 2.0, 2.5, cov_matrix=cov_matrix)
y, x = np.mgrid[0:5, 0:5]
g = model(x, y)
g_ref = [[4.3744505, 5.8413977, 7.42988694, 9.00160175, 10.38794269],
[8.83290201, 10.81772851, 12.61946384, 14.02225593, 14.84113227],
[13.68528889, 15.37184621, 16.44637743, 16.76048705, 16.26953638],
[16.26953638, 16.76048705, 16.44637743, 15.37184621, 13.68528889],
[14.84113227, 14.02225593, 12.61946384, 10.81772851, 8.83290201]]
assert_allclose(g, g_ref, rtol=0, atol=1e-6)
def test_Gaussian2DRotation():
amplitude = 42
x_mean, y_mean = 0, 0
x_stddev, y_stddev = 2, 3
theta = Angle(10, 'deg')
pars = dict(amplitude=amplitude, x_mean=x_mean, y_mean=y_mean,
x_stddev=x_stddev, y_stddev=y_stddev)
rotation = models.Rotation2D(angle=theta.degree)
point1 = (x_mean + 2 * x_stddev, y_mean + 2 * y_stddev)
point2 = rotation(*point1)
g1 = models.Gaussian2D(theta=0, **pars)
g2 = models.Gaussian2D(theta=theta.radian, **pars)
value1 = g1(*point1)
value2 = g2(*point2)
assert_allclose(value1, value2)
def test_Gaussian2D_invalid_inputs():
x_stddev = 5.1
y_stddev = 3.3
theta = 10
cov_matrix = [[49., -16.], [-16., 9.]]
# first make sure the valid ones are OK
models.Gaussian2D()
models.Gaussian2D(x_stddev=x_stddev, y_stddev=y_stddev, theta=theta)
models.Gaussian2D(x_stddev=None, y_stddev=y_stddev, theta=theta)
models.Gaussian2D(x_stddev=x_stddev, y_stddev=None, theta=theta)
models.Gaussian2D(x_stddev=x_stddev, y_stddev=y_stddev, theta=None)
models.Gaussian2D(cov_matrix=cov_matrix)
with pytest.raises(InputParameterError):
models.Gaussian2D(x_stddev=0, cov_matrix=cov_matrix)
with pytest.raises(InputParameterError):
models.Gaussian2D(y_stddev=0, cov_matrix=cov_matrix)
with pytest.raises(InputParameterError):
models.Gaussian2D(theta=0, cov_matrix=cov_matrix)
@pytest.mark.parametrize('gamma', (10, -10))
def test_moffat_fwhm(gamma):
ans = 34.641016151377542
kwargs = {'gamma': gamma, 'alpha': 0.5}
m1 = models.Moffat1D(**kwargs)
m2 = models.Moffat2D(**kwargs)
assert_allclose([m1.fwhm, m2.fwhm], ans)
assert_array_less(0, [m1.fwhm, m2.fwhm])
def test_RedshiftScaleFactor():
"""Like ``test_ScaleModel()``."""
# Scale by a scalar
m = models.RedshiftScaleFactor(0.4)
assert m(0) == 0
assert_array_equal(m([1, 2]), [1.4, 2.8])
assert_allclose(m.inverse(m([1, 2])), [1, 2])
# Scale by a list
m = models.RedshiftScaleFactor([-0.5, 0, 0.5], n_models=3)
assert_array_equal(m(0), 0)
assert_array_equal(m([1, 2], model_set_axis=False),
[[0.5, 1], [1, 2], [1.5, 3]])
assert_allclose(m.inverse(m([1, 2], model_set_axis=False)),
[[1, 2], [1, 2], [1, 2]])
def test_Ellipse2D():
"""Test Ellipse2D model."""
amplitude = 7.5
x0, y0 = 15, 15
theta = Angle(45, 'deg')
em = models.Ellipse2D(amplitude, x0, y0, 7, 3, theta.radian)
y, x = np.mgrid[0:30, 0:30]
e = em(x, y)
assert np.all(e[e > 0] == amplitude)
assert e[y0, x0] == amplitude
rotation = models.Rotation2D(angle=theta.degree)
point1 = [2, 0] # Rotation2D center is (0, 0)
point2 = rotation(*point1)
point1 = np.array(point1) + [x0, y0]
point2 = np.array(point2) + [x0, y0]
e1 = models.Ellipse2D(amplitude, x0, y0, 7, 3, theta=0.)
e2 = models.Ellipse2D(amplitude, x0, y0, 7, 3, theta=theta.radian)
assert e1(*point1) == e2(*point2)
def test_Ellipse2D_circular():
"""Test that circular Ellipse2D agrees with Disk2D [3736]."""
amplitude = 7.5
radius = 10
size = (radius * 2) + 1
y, x = np.mgrid[0:size, 0:size]
ellipse = models.Ellipse2D(amplitude, radius, radius, radius, radius,
theta=0)(x, y)
disk = models.Disk2D(amplitude, radius, radius, radius)(x, y)
assert np.all(ellipse == disk)
def test_Scale_inverse():
m = models.Scale(1.2345)
assert_allclose(m.inverse(m(6.789)), 6.789)
def test_Multiply_inverse():
m = models.Multiply(1.2345)
assert_allclose(m.inverse(m(6.789)), 6.789)
def test_Shift_inverse():
m = models.Shift(1.2345)
assert_allclose(m.inverse(m(6.789)), 6.789)
@pytest.mark.skipif('not HAS_SCIPY')
def test_Shift_model_levmar_fit():
"""Test fitting Shift model with LevMarLSQFitter (issue #6103)."""
init_model = models.Shift()
x = np.arange(10)
y = x+0.1
fitter = fitting.LevMarLSQFitter()
fitted_model = fitter(init_model, x, y)
assert_allclose(fitted_model.parameters, [0.1], atol=1e-15)
def test_Shift_model_set_linear_fit():
"""Test linear fitting of Shift model (issue #6103)."""
init_model = models.Shift(offset=[0, 0], n_models=2)
x = np.arange(10)
yy = np.array([x+0.1, x-0.2])
fitter = fitting.LinearLSQFitter()
fitted_model = fitter(init_model, x, yy)
assert_allclose(fitted_model.parameters, [0.1, -0.2], atol=1e-15)
@pytest.mark.parametrize('Model', (models.Scale, models.Multiply))
def test_Scale_model_set_linear_fit(Model):
"""Test linear fitting of Scale model (#6103)."""
init_model = Model(factor=[0, 0], n_models=2)
x = np.arange(-3, 7)
yy = np.array([1.15*x, 0.96*x])
fitter = fitting.LinearLSQFitter()
fitted_model = fitter(init_model, x, yy)
assert_allclose(fitted_model.parameters, [1.15, 0.96], atol=1e-15)
# https://github.com/astropy/astropy/issues/6178
def test_Ring2D_rout():
m = models.Ring2D(amplitude=1, x_0=1, y_0=1, r_in=2, r_out=5)
assert m.width.value == 3
@pytest.mark.skipif("not HAS_SCIPY")
def test_Voigt1D():
voi = models.Voigt1D(amplitude_L=-0.5, x_0=1.0, fwhm_L=5.0, fwhm_G=5.0)
xarr = np.linspace(-5.0, 5.0, num=40)
yarr = voi(xarr)
voi_init = models.Voigt1D(amplitude_L=-1.0, x_0=1.0, fwhm_L=5.0, fwhm_G=5.0)
fitter = fitting.LevMarLSQFitter()
voi_fit = fitter(voi_init, xarr, yarr)
assert_allclose(voi_fit.param_sets, voi.param_sets)
@pytest.mark.skipif("not HAS_SCIPY")
def test_compound_models_with_class_variables():
models_2d = [models.AiryDisk2D, models.Sersic2D]
models_1d = [models.Sersic1D]
for model_2d in models_2d:
class CompoundModel2D(models.Const2D + model_2d):
pass
x, y = np.mgrid[:10, :10]
f = CompoundModel2D()(x, y)
assert f.shape == (10, 10)
for model_1d in models_1d:
class CompoundModel1D(models.Const1D + model_1d):
pass
x = np.arange(10)
f = CompoundModel1D()(x)
assert f.shape == (10,)