spacetelescope
imexam fails with astropy 5.2
After uploading astropy 5.2, I found that the CI tests of imexam no longer pass. Specifically, the following test fails:
______________________________ test_gauss_center _______________________________
def test_gauss_center():
"""Check the gaussian center fitting."""
from astropy.convolution import Gaussian2DKernel
# This creates a 2D normalized gaussian kernal with
# a set amplitude. Guess off-center
amp = 0.0015915494309189533
size = 81.0
sigma = 10.0
gaussian_2D_kernel = Gaussian2DKernel(sigma, x_size=size, y_size=size)
plots = Imexamine()
plots.set_data(gaussian_2D_kernel.array)
a, xx, yy, xs, ys = plots.gauss_center(37, 37)
> assert_allclose(amp, a, 1e-6)
E AssertionError:
E Not equal to tolerance rtol=1e-06, atol=0
E
E Mismatched elements: 1 / 1 (100%)
E Max absolute difference: 1.61872075e-07
E Max relative difference: 0.0001017
E x: array(0.001592)
E y: array(0.001592)
/usr/lib/python3/dist-packages/imexam/tests/test_imexamine.py:128: AssertionError
----------------------------- Captured stdout call -----------------------------
xc=40.0000 yc=40.0000
------------------------------ Captured log call -------------------------------
INFO imexam.util:imexamine.py:1015 xc=40.0000 yc=40.0000
Shall one just increase the rtol or is this a real problem?
See https://github.com/astropy/astropy/issues/14226#issuecomment-2631375146 – the definition of amplitude/normalisation has changed with astropy 5.2, so the target value amp would have slightly increased.
You could update the value for amp (which would break astropy < 5.2 though), increase rtol or increase size to 101 – that would keep the truncated parts small enough to hold the deviation below 1e-06 as well.
That should work up to astropy 6.1.x; with 7.0.0 however all the fitter tests are failing with
FAILED imexam/tests/test_imexamine.py::test_line_fit - ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (7,) + inho...
FAILED imexam/tests/test_imexamine.py::test_column_fit - ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (7,) + inho...
FAILED imexam/tests/test_imexamine.py::test_gauss_center - ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (7,) + inho...
FAILED imexam/tests/test_imexamine.py::test_radial_profile - ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (7,) + inho...
FAILED imexam/tests/test_imexamine.py::test_radial_profile_cumulative - ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (7,) + inho...
which is due to a bug in the Jacobian fit_deriv for CompondModel and fixed in astropy/astropy#17618 (7.0.1).