def __init__(self, grid, part_grid=False):
self.grid = grid
if part_grid:
grid.ctx().config().set_boolean("geometry.part_grid.enabled", True)
self.v = PISM.IceModelVec2V(grid, "velocity", PISM.WITHOUT_GHOSTS)
self.Q = PISM.IceModelVec2Stag(grid, "Q", PISM.WITHOUT_GHOSTS)
self.v_bc_mask = PISM.IceModelVec2Int(grid, "v_bc_mask", PISM.WITHOUT_GHOSTS)
self.H_bc_mask = PISM.IceModelVec2Int(grid, "H_bc_mask", PISM.WITHOUT_GHOSTS)
self.ge = PISM.GeometryEvolution(grid)
self.geometry = PISM.Geometry(grid)
self.reset()
def run(Mx, My, t_final, part_grid, C=1.0):
"Test GeometryEvolution::step()"
ctx = PISM.Context().ctx
config = PISM.Context().config
config.set_flag("geometry.part_grid.enabled", part_grid)
grid = PISM.IceGrid_Shallow(ctx, 1, 1, 0, 0, Mx, My, PISM.CELL_CORNER,
PISM.NOT_PERIODIC)
assert t_final <= 1.0
L = min(grid.Lx(), grid.Ly())
R_inner = 0.25 * L
spreading_velocity = 0.7
R_outer = R_inner + spreading_velocity * t_final
geometry = PISM.Geometry(grid)
v = PISM.IceModelVec2V(grid, "velocity", PISM.WITHOUT_GHOSTS)
Q = PISM.IceModelVec2Stag(grid, "Q", PISM.WITHOUT_GHOSTS)
v_bc_mask = PISM.IceModelVec2Int(grid, "v_bc_mask", PISM.WITHOUT_GHOSTS)
H_bc_mask = PISM.IceModelVec2Int(grid, "H_bc_mask", PISM.WITHOUT_GHOSTS)
ge = PISM.GeometryEvolution(grid)
# grid info
geometry.latitude.set(0.0)
geometry.longitude.set(0.0)
# environment
geometry.bed_elevation.set(-10.0)
geometry.sea_level_elevation.set(0.0)
# set initial ice thickness
disc(geometry.ice_thickness, 0, 0, 1, R_inner, R_inner)
geometry.ice_area_specific_volume.set(0.0)
geometry.ensure_consistency(0.0)
set_velocity(spreading_velocity, v)
v_bc_mask.set(0.0)
disc(H_bc_mask, 0, 0, 1, R_inner, R_inner)
profiling = ctx.profiling()
profiling.start()
t = 0.0
j = 0
profiling.stage_begin("ge")
while t < t_final:
cfl_data = PISM.max_timestep_cfl_2d(geometry.ice_thickness,
geometry.cell_type, v)
dt = cfl_data.dt_max.value() * C
if t + dt > t_final:
dt = t_final - t
log.message(2, "{}, {}\n".format(t, dt))
profiling.begin("step")
ge.flow_step(geometry, dt, v, Q, v_bc_mask, H_bc_mask)
profiling.end("step")
profiling.begin("modify")
ge.apply_flux_divergence(geometry)
geometry.ensure_consistency(0.0)
profiling.end("modify")
t += dt
j += 1
profiling.stage_end("ge")
profiling.report("profiling_%d_%d.py" % (Mx, My))
return geometry
def grounding_line_flux_test():
"""Test that the grounding line flux approximation
The grounding line flux should be zero if the direction of the flux is parallel to the
grounding line.
"""
# Mx and My have to be odd
Mx = 51
My = 51
Lx = 1e5
Ly = 1e5
grid = PISM.testing.shallow_grid(Mx=Mx, My=My, Lx=Lx, Ly=Ly)
geometry = PISM.Geometry(grid)
with PISM.vec.Access([geometry.bed_elevation, geometry.ice_thickness]):
for i, j in grid.points():
x = grid.x(i)
y = grid.y(j)
C = 0.25 * (Lx + Ly)
if x - y <= 0.0:
geometry.bed_elevation[i, j] = 10.0
elif x + y >= C:
geometry.bed_elevation[i, j] = 10.0
else:
geometry.bed_elevation[i, j] = -10.0
if i == 0 or j == 0 or i == Mx - 1 or j == My - 1:
geometry.ice_thickness[i, j] = 0.0
elif x + y < C:
geometry.ice_thickness[i, j] = 10.0
else:
geometry.ice_thickness[i, j] = 0.0
geometry.ensure_consistency(0)
velocity = PISM.IceModelVec2V(grid, "velocity", PISM.WITHOUT_GHOSTS)
thk_bc_mask = PISM.IceModelVec2Int(grid, "thk_bc_mask",
PISM.WITHOUT_GHOSTS)
thk_bc_mask.set(0)
sia_flux = PISM.IceModelVec2Stag(grid, "sia_flux", PISM.WITHOUT_GHOSTS)
sia_flux.set(0)
dt = 365 * 86400
V = 1.0 / dt
with PISM.vec.Access(velocity):
for i, j in grid.points():
velocity[i, j].u = V
velocity[i, j].v = V
geometry_evolution = PISM.GeometryEvolution(grid)
geometry_evolution.flow_step(geometry, dt, velocity, sia_flux, thk_bc_mask)
gl_flux = PISM.IceModelVec2S(grid, "grounding_line_flux",
PISM.WITHOUT_GHOSTS)
PISM.grounding_line_flux(
geometry.cell_type,
geometry_evolution.flux_staggered(),
dt,
False, # replace values instead of adding
gl_flux)
NORM_INFINITY = 3
np.testing.assert_almost_equal(gl_flux.norm(NORM_INFINITY), 0.0)
def mass_transport_test(t_final, C=1.0):
"Test GeometryEvolution::step()"
ctx = PISM.Context().ctx
config = PISM.Context().config
# config.set_boolean("geometry.part_grid.enabled", True)
Mx = 101
My = 101
grid = PISM.IceGrid_Shallow(ctx, 1, 1, 0, 0, Mx, My, PISM.CELL_CORNER,
PISM.NOT_PERIODIC)
geometry = PISM.Geometry(grid)
v = PISM.model.create2dVelocityVec(grid)
Q = PISM.IceModelVec2Stag()
Q.create(grid, "Q", PISM.WITHOUT_GHOSTS)
v_bc_mask = PISM.IceModelVec2Int()
v_bc_mask.create(grid, "v_bc_mask", PISM.WITHOUT_GHOSTS)
H_bc_mask = PISM.IceModelVec2Int()
H_bc_mask.create(grid, "H_bc_mask", PISM.WITHOUT_GHOSTS)
SMB = PISM.IceModelVec2S()
SMB.create(grid, "SMB", PISM.WITHOUT_GHOSTS)
BMR = PISM.IceModelVec2S()
BMR.create(grid, "BMR", PISM.WITHOUT_GHOSTS)
ge = PISM.GeometryEvolution(grid)
# grid info
geometry.cell_area().set(grid.dx() * grid.dy())
geometry.latitude().set(0.0)
geometry.longitude().set(0.0)
# environment
geometry.bed_elevation().set(-10.0)
geometry.sea_level_elevation().set(0.0)
# ice
set_ice_thickness(geometry.ice_thickness(), time=1)
geometry.ice_area_specific_volume().set(0.0)
geometry.ensure_consistency(0.0)
set_velocity(v)
v_bc_mask.set(
0.0) # all points are velocity B.C. points (but it does not matter)
H_bc_mask.set(0.0)
SMB.set(0.0)
BMR.set(0.0)
profiling = ctx.profiling()
profiling.start()
t = 0.0
j = 0
profiling.stage_begin("ge")
while t < t_final:
dt = PISM.max_timestep_cfl_2d(geometry.ice_thickness(),
geometry.cell_type(),
v).dt_max.value() * C
if t + dt > t_final:
dt = t_final - t
log.message(2, "{}, {}\n".format(t, dt))
profiling.begin("dump")
geometry.ice_thickness().dump("thk-%05d.nc" % (j + 1))
geometry.ice_area_specific_volume().dump("Href-%05d.nc" % (j + 1))
profiling.end("dump")
profiling.begin("step")
ge.step(geometry, dt, v, Q, v_bc_mask, H_bc_mask, SMB, BMR)
profiling.end("step")
profiling.begin("modify")
geometry.ice_thickness().add(1.0, ge.thickness_change_due_to_flow())
geometry.ice_area_specific_volume().add(
1.0, ge.area_specific_volume_change_due_to_flow())
geometry.ensure_consistency(0.0)
profiling.end("modify")
t += dt
j += 1
profiling.stage_end("ge")
profiling.report("profiling.py")
return geometry, dt
