def test_nemo_grid(mode):
data_path = path.join(path.dirname(__file__), 'test_data/')
filenames = {
'U': data_path + 'Uu_eastward_nemo_cross_180lon.nc',
'V': data_path + 'Vv_eastward_nemo_cross_180lon.nc',
'mesh_mask': data_path + 'mask_nemo_cross_180lon.nc'
}
variables = {'U': 'U', 'V': 'V'}
dimensions = {'lon': 'glamf', 'lat': 'gphif'}
field_set = FieldSet.from_nemo(filenames, variables, dimensions)
# test ParticleSet.from_field on curvilinear grids
ParticleSet.from_field(field_set,
ptype[mode],
start_field=field_set.U,
size=5)
def sampleVel(particle, fieldset, time, dt):
(particle.zonal, particle.meridional) = fieldset.UV[time, particle.lon,
particle.lat,
particle.depth]
class MyParticle(ptype[mode]):
zonal = Variable('zonal', dtype=np.float32, initial=0.)
meridional = Variable('meridional', dtype=np.float32, initial=0.)
lonp = 175.5
latp = 81.5
pset = ParticleSet.from_list(field_set, MyParticle, lon=[lonp], lat=[latp])
pset.execute(pset.Kernel(sampleVel), runtime=0, dt=0)
u = field_set.U.units.to_source(pset[0].zonal, lonp, latp, 0)
v = field_set.V.units.to_source(pset[0].meridional, lonp, latp, 0)
assert abs(u - 1) < 1e-4
assert abs(v) < 1e-4
def test_random_field(mode, k_sample_p, xdim=20, ydim=20, npart=100):
"""Sampling test that tests for overshoots by sampling a field of
random numbers between 0 and 1.
"""
np.random.seed(123456)
dimensions = {
'lon': np.linspace(0., 1., xdim, dtype=np.float32),
'lat': np.linspace(0., 1., ydim, dtype=np.float32)
}
data = {
'U': np.zeros((xdim, ydim), dtype=np.float32),
'V': np.zeros((xdim, ydim), dtype=np.float32),
'P': np.random.uniform(0, 1., size=(xdim, ydim)),
'start': np.ones((xdim, ydim), dtype=np.float32)
}
fieldset = FieldSet.from_data(data,
dimensions,
mesh='flat',
transpose=True)
pset = ParticleSet.from_field(fieldset,
size=npart,
pclass=pclass(mode),
start_field=fieldset.start)
pset.execute(k_sample_p, endtime=1., dt=1.0)
sampled = pset.p
assert ((sampled >= 0.).all())
def test_pset_create_field_curvi(npart=100):
np.random.seed(123456)
r_v = np.linspace(.25, 2, 20)
theta_v = np.linspace(0, np.pi / 2, 200)
dtheta = theta_v[1] - theta_v[0]
dr = r_v[1] - r_v[0]
(r, theta) = np.meshgrid(r_v, theta_v)
x = -1 + r * np.cos(theta)
y = -1 + r * np.sin(theta)
grid = CurvilinearZGrid(x, y)
u = np.ones(x.shape)
v = np.where(np.logical_and(theta > np.pi / 4, theta < np.pi / 3), 1, 0)
ufield = Field('U', u, grid=grid)
vfield = Field('V', v, grid=grid)
fieldset = FieldSet(ufield, vfield)
pset = ParticleSet.from_field(fieldset,
size=npart,
pclass=ptype['scipy'],
start_field=fieldset.V)
lons = np.array([p.lon + 1 for p in pset])
lats = np.array([p.lat + 1 for p in pset])
thetas = np.arctan2(lats, lons)
rs = np.sqrt(lons * lons + lats * lats)
test = np.pi / 4 - dtheta < thetas
test *= thetas < np.pi / 3 + dtheta
test *= rs > .25 - dr
test *= rs < 2 + dr
assert np.all(test)
def test_random_field(mode, k_sample_p, xdim=20, ydim=20, npart=100):
"""Sampling test that test for overshoots by sampling a field of
random numbers between 0 and 1.
"""
np.random.seed(123456)
lon = np.linspace(0., 1., xdim, dtype=np.float32)
lat = np.linspace(0., 1., ydim, dtype=np.float32)
U = np.zeros((xdim, ydim), dtype=np.float32)
V = np.zeros((xdim, ydim), dtype=np.float32)
P = np.random.uniform(0, 1., size=(xdim, ydim))
S = np.ones((xdim, ydim), dtype=np.float32)
grid = Grid.from_data(U,
lon,
lat,
V,
lon,
lat,
mesh='flat',
field_data={
'P': np.asarray(P, dtype=np.float32),
'start': S
})
pset = ParticleSet.from_field(grid,
size=npart,
pclass=pclass(mode),
start_field=grid.start)
pset.execute(k_sample_p, endtime=1., dt=1.0)
sampled = np.array([p.p for p in pset])
assert ((sampled >= 0.).all())
def test_pset_create_field(fieldset, mode, npart=100):
np.random.seed(123456)
shape = (fieldset.U.lon.size, fieldset.U.lat.size)
K = Field('K', lon=fieldset.U.lon, lat=fieldset.U.lat,
data=np.ones(shape, dtype=np.float32), transpose=True)
pset = ParticleSet.from_field(fieldset, size=npart, pclass=ptype[mode], start_field=K)
assert (np.array([p.lon for p in pset]) <= K.lon[-1]).all()
assert (np.array([p.lon for p in pset]) >= K.lon[0]).all()
assert (np.array([p.lat for p in pset]) <= K.lat[-1]).all()
assert (np.array([p.lat for p in pset]) >= K.lat[0]).all()
def test_from_field_exact_val(staggered_grid):
xdim = 4
ydim = 3
lon = np.linspace(-1, 2, xdim, dtype=np.float32)
lat = np.linspace(50, 52, ydim, dtype=np.float32)
dimensions = {'lat': lat, 'lon': lon}
if staggered_grid == 'Agrid':
U = np.zeros((ydim, xdim), dtype=np.float32)
V = np.zeros((ydim, xdim), dtype=np.float32)
data = {
'U': np.array(U, dtype=np.float32),
'V': np.array(V, dtype=np.float32)
}
mask = np.array([[1, 1, 0, 0], [1, 1, 1, 0], [1, 1, 1, 1]])
fieldset = FieldSet.from_data(data, dimensions, mesh='flat')
FMask = Field('mask', mask, lon, lat)
fieldset.add_field(FMask)
elif staggered_grid == 'Cgrid':
U = np.array([[0, 0, 0, 0], [1, 0, 0, 0], [1, 1, 0, 0]])
V = np.array([[0, 1, 0, 0], [0, 1, 0, 0], [0, 1, 1, 0]])
data = {
'U': np.array(U, dtype=np.float32),
'V': np.array(V, dtype=np.float32)
}
mask = np.array([[-1, -1, -1, -1], [-1, 1, 0, 0], [-1, 1, 1, 0]])
fieldset = FieldSet.from_data(data, dimensions, mesh='flat')
fieldset.U.interp_method = 'cgrid_velocity'
fieldset.V.interp_method = 'cgrid_velocity'
FMask = Field('mask', mask, lon, lat, interp_method='cgrid_tracer')
fieldset.add_field(FMask)
class SampleParticle(ptype['scipy']):
mask = Variable('mask', initial=fieldset.mask)
pset = ParticleSet.from_field(fieldset,
size=400,
pclass=SampleParticle,
start_field=FMask,
time=0)
# pset.show(field=FMask)
assert np.allclose([p.mask for p in pset], 1)
assert (np.array([p.lon for p in pset]) <= 1).all()
test = np.logical_or(
np.array([p.lon for p in pset]) <= 0,
np.array([p.lat for p in pset]) >= 51)
assert test.all()
def test_pset_create_field(grid, mode, npart=100):
np.random.seed(123456)
shape = (grid.U.lon.size, grid.U.lat.size)
K = Field('K',
lon=grid.U.lon,
lat=grid.U.lat,
data=np.ones(shape, dtype=np.float32))
pset = ParticleSet.from_field(grid,
size=npart,
pclass=ptype[mode],
start_field=K)
assert (np.array([p.lon for p in pset]) <= 1.).all()
assert (np.array([p.lon for p in pset]) >= 0.).all()
assert (np.array([p.lat for p in pset]) <= 1.).all()
assert (np.array([p.lat for p in pset]) >= 0.).all()
def test_pset_from_field(mode, xdim=10, ydim=20, npart=10000):
np.random.seed(123456)
dimensions = {'lon': np.linspace(0., 1., xdim, dtype=np.float32),
'lat': np.linspace(0., 1., ydim, dtype=np.float32)}
startfield = np.ones((xdim, ydim), dtype=np.float32)
for x in range(xdim):
startfield[x, :] = x
data = {'U': np.zeros((xdim, ydim), dtype=np.float32),
'V': np.zeros((xdim, ydim), dtype=np.float32),
'start': startfield}
fieldset = FieldSet.from_data(data, dimensions, mesh='flat', transpose=True)
pset = ParticleSet.from_field(fieldset, size=npart, pclass=pclass(mode),
start_field=fieldset.start)
densfield = Field(name='densfield', data=np.zeros((xdim+1, ydim+1), dtype=np.float32),
lon=np.linspace(-1./(xdim*2), 1.+1./(xdim*2), xdim+1, dtype=np.float32),
lat=np.linspace(-1./(ydim*2), 1.+1./(ydim*2), ydim+1, dtype=np.float32), transpose=True)
pdens = pset.density(field=densfield, relative=True)[:-1, :-1]
assert np.allclose(np.transpose(pdens), startfield/np.sum(startfield), atol=1e-2)
def test_pset_from_field(xdim=10, ydim=10, npart=10000):
np.random.seed(123456)
dimensions = {
'lon': np.linspace(0., 1., xdim, dtype=np.float32),
'lat': np.linspace(0., 1., ydim, dtype=np.float32)
}
startfield = np.ones((xdim, ydim), dtype=np.float32)
for x in range(xdim):
startfield[x, :] = x
data = {
'U': np.zeros((xdim, ydim), dtype=np.float32),
'V': np.zeros((xdim, ydim), dtype=np.float32),
'start': startfield
}
fieldset = FieldSet.from_data(data, dimensions, mesh='flat')
pset = ParticleSet.from_field(fieldset,
size=npart,
pclass=JITParticle,
start_field=fieldset.start)
pdens = pset.density(area_scale=False, relative=True)
assert np.allclose(pdens, startfield / np.sum(startfield), atol=5e-3)
