def test_vmec(self):
"""
If we run VMEC using a given boundary shape, then convert the
boundary to the Henneberg representation and convert back and
run VMEC again, the rotational transform should be almost
identical.
"""
vmec = Vmec(os.path.join(TEST_DIR, 'input.cfqs_2b40'))
vmec.run()
iota1 = vmec.wout.iotaf
vmec.boundary = SurfaceHenneberg.from_RZFourier(vmec.boundary, 1)
vmec.need_to_run_code = True
vmec.run()
iota2 = vmec.wout.iotaf
logger.info(f'iota1: {iota1}')
logger.info(f'iota2: {iota2}')
logger.info(f'diff: {iota1 - iota2}')
np.testing.assert_allclose(iota1, iota2, atol=1e-3, rtol=1e-3)
# But if the 2 iota profiles are _exactly_ the same, vmec must
# not have actually used the converted boundary.
self.assertTrue(np.max(np.abs(iota1 - iota2)) > 1e-12)
def test_from_RZFourier(self):
"""
Take a VMEC boundary in the original RZFourier representation,
convert it to the Henneberg representation, and convert it
back to the RZFourier representation. Coordinate-independent
quantities like the volume and area should not change. If the
result is converted to the Henneberg representation yet again,
the degrees of freedom should be unchanged from the earlier
Henneberg representation.
"""
# Prepare some arbitrary points for testing gamma_lin:
nlist = 15
theta_list = np.linspace(-0.2, 0.8, nlist)
phi_list = theta_list**2 - 0.5
# Try a QI, QA, and a QH:
files = [
'input.W7-X_standard_configuration', 'input.cfqs_2b40',
'input.NuhrenbergZille_1988_QHS'
]
alpha_facs = [1, 1, -1]
for test_file, alpha_fac in zip(files, alpha_facs):
vmec = Vmec(os.path.join(TEST_DIR, test_file))
surf1 = vmec.boundary
surf2 = SurfaceHenneberg.from_RZFourier(surf1, alpha_fac)
self.assertEqual(surf2.num_dofs(), len(surf2.get_dofs()))
surf3 = surf2.to_RZFourier()
# Test gamma_lin:
gamma2 = np.zeros((nlist, 3))
gamma3 = np.zeros((nlist, 3))
surf2.gamma_lin(gamma2, phi_list, theta_list)
surf3.gamma_lin(gamma3, phi_list, theta_list)
np.testing.assert_allclose(gamma2, gamma3, atol=1e-13, rtol=1e-13)
# Test other surface functions:
np.testing.assert_allclose(surf2.gamma(),
surf3.gamma(),
atol=1e-13,
rtol=1e-13)
np.testing.assert_allclose(surf2.gammadash2(),
surf3.gammadash2(),
atol=1e-12,
rtol=1e-12)
np.testing.assert_allclose(surf2.gammadash1(),
surf3.gammadash1(),
atol=1e-11,
rtol=1e-11)
np.testing.assert_allclose(surf1.volume(),
surf2.volume(),
atol=0,
rtol=1e-3)
np.testing.assert_allclose(surf1.volume(),
surf3.volume(),
atol=0,
rtol=1e-3)
np.testing.assert_allclose(surf1.area(),
surf2.area(),
atol=0,
rtol=1e-3)
np.testing.assert_allclose(surf1.area(),
surf3.area(),
atol=0,
rtol=1e-3)
surf4 = SurfaceHenneberg.from_RZFourier(surf3,
alpha_fac,
mmax=surf2.mmax,
nmax=surf2.nmax)
np.testing.assert_allclose(surf2.R0nH,
surf4.R0nH,
atol=1e-12,
rtol=1e-4)
np.testing.assert_allclose(surf2.Z0nH,
surf4.Z0nH,
atol=1e-12,
rtol=1e-4)
np.testing.assert_allclose(surf2.bn,
surf4.bn,
atol=1e-12,
rtol=1e-4)
np.testing.assert_allclose(surf2.rhomn,
surf4.rhomn,
atol=1e-8,
rtol=1e-4)