def thickness_calving_test():
"Test the time-dependent thickness calving threshold"
grid = PISM.testing.shallow_grid(Mx=5, My=5)
geometry = PISM.Geometry(grid)
# set ice thickness
H = geometry.ice_thickness
with PISM.vec.Access(H):
for i, j in grid.points():
if i >= 3 and j >= 3:
H[i, j] = 0
elif i > 2 and j == 2:
H[i, j] = 100
elif i >= 1 and j >= 1:
H[i, j] = 150
else:
H[i, j] = 200
# set bed elevation low enough to ensure that all ice is floating
geometry.bed_elevation.set(-1000)
geometry.ensure_consistency(0.0)
config = PISM.Context().config
filename = PISM.testing.filename("threshold_thickness_")
day = 86400.0
times = [0, 30, 60]
time_bounds = [-15, 15, 45, 75]
time_units = "days since 1-1-1"
values = [100, 150, 200]
try:
# create the time-dependent thickness threshold
PISM.testing.create_forcing(grid,
filename,
"thickness_calving_threshold",
"m",
values,
time_units,
times=times,
time_bounds=time_bounds)
config.set_string("calving.thickness_calving.file", filename)
calving = PISM.CalvingAtThickness(grid)
calving.init()
# run the calving model
calving.update(0 * day, 30 * day, geometry.cell_type,
geometry.ice_thickness)
ref1 = np.array([[200., 200., 200., 200., 200.],
[200., 150., 150., 150., 150.],
[200., 150., 150., 0.,
0.], [200., 150., 150., 0., 0.],
[200., 150., 150., 0., 0.]])
np.testing.assert_almost_equal(geometry.ice_thickness.numpy(), ref1)
calving.update(30 * day, 60 * day, geometry.cell_type,
geometry.ice_thickness)
ref2 = np.array([[200., 200., 200., 200., 200.],
[200., 150., 150., 0., 0.], [200., 150., 0., 0., 0.],
[200., 150., 0., 0., 0.], [200., 150., 0., 0., 0.]])
np.testing.assert_almost_equal(geometry.ice_thickness.numpy(), ref2)
finally:
# clean up
os.remove(filename)
# restore default values
config.set_string("calving.thickness_calving.file", "")
