def test_starfind_blind_fwhm(self):
size = (512, 512)
number = 12
low, high = (15000, 60000)
sky = 800
rdnoise = 20
sigma = 2
theta = 0
threshold = 8
x, y, f = gen_position_flux(size, number, low, high, rng_seed=456)
x, y, f = self.resort_sources(x, y, f)
im = gen_image(size,
x,
y,
f,
sky,
rdnoise,
model='gaussian',
sigma=sigma,
theta=theta)
sources = starfind(im, threshold, sky, rdnoise)
assert_equal(len(sources), number)
assert_almost_equal(sources['x'], x, decimal=1)
assert_almost_equal(sources['y'], y, decimal=1)
assert_almost_equal(sources.meta['astropop fwhm'],
sigma * 2.355,
decimal=2)
def test_starfind_strong_weak(self):
size = (100, 200)
posx = (50, 150)
posy = (40, 60)
sky = 800
rdnoise = 20
flux = (64000, 6000)
theta = 0
fwhm = 3
sigma = fwhm * gaussian_fwhm_to_sigma
threshold = 10
im = gen_image(size,
posx,
posy,
flux,
sky,
rdnoise,
model='gaussian',
sigma=sigma,
theta=theta)
sources = starfind(im, threshold, sky, rdnoise, fwhm)
assert_equal(len(sources), 2)
assert_almost_equal(sources['x'], posx, decimal=1)
assert_almost_equal(sources['y'], posy, decimal=1)
assert_almost_equal(sources.meta['astropop fwhm'],
sigma * 2.355,
decimal=1)
def test_starfind_one_star(self):
size = (128, 128)
x, y = (64, 64)
f = 80000
sky = 70
rdnoise = 20
sigma = 5
theta = 0
fwhm = 5 # dummy low value
threshold = 10
im = gen_image(size, [x], [y], [f],
sky,
rdnoise,
model='gaussian',
sigma=sigma,
theta=theta)
sources = starfind(im, threshold, sky, rdnoise, fwhm)
assert_equal(len(sources), 1)
assert_almost_equal(sources['x'], x, decimal=0)
assert_almost_equal(sources['y'], y, decimal=0)
assert_almost_equal(sources.meta['astropop fwhm'],
sigma * 2.355,
decimal=1)
def test_starfind_one_star_subpixel(self):
size = (128, 128)
pos = (54.32, 47.86)
im = gen_image(size, [pos[0]], [pos[1]], [45000],
800,
0,
sigma=[5 * gaussian_fwhm_to_sigma],
skip_poisson=True)
sources = starfind(im, 5, 800, 10)
assert_equal(len(sources), 1)
# no error, 2 decimals ok!
assert_almost_equal(sources[0]['x'], pos[0], decimal=2)
assert_almost_equal(sources[0]['y'], pos[1], decimal=2)
def test_starfind_rejection(self):
size = (128, 128)
pos_x = [20, 60, 100, 40, 80, 50]
pos_y = [20, 30, 40, 50, 60, 85]
sky = 70
rdnoise = 20
flux = [30000] * 6
theta = 0
fwhm = 3
sig_base = gaussian_fwhm_to_sigma * fwhm
sigma_x = np.array([1, 0.5, 1, 2.0, 0.1, 1]) * sig_base
sigma_y = np.array([1, 1.0, 1, 0.5, 0.1, 1]) * sig_base
threshold = 10
# stars 0, 2 -> passed
# star 4 -> rejected by sharpness
# stars 1, 3 -> rejected by roundness
im = gen_image(size,
pos_x,
pos_y,
flux,
sky,
rdnoise,
model='gaussian',
sigma=(sigma_x, sigma_y),
theta=theta)
sources = starfind(im,
threshold,
sky,
rdnoise,
sharp_limit=(0.3, 0.6),
round_limit=(-0.5, 0.5))
assert_equal(len(sources), 3)
assert_almost_equal(sources['x'], [20, 100, 50], decimal=0)
assert_almost_equal(sources['y'], [20, 40, 85], decimal=0)
assert_almost_equal(sources.meta['astropop fwhm'], fwhm, decimal=1)