def bed_def_given_test(self):
"Test -bed_def given"
model = PISM.GivenTopography(self.grid)
geometry = PISM.Geometry(self.grid)
geometry.ice_thickness.set(0.0)
geometry.sea_level_elevation.set(0.0)
opts = PISM.process_input_options(ctx.com, ctx.config)
model.init(opts, geometry.ice_thickness, geometry.sea_level_elevation)
# use dt == 0 to sample topg_delta at a predictable time
dt = 0.0
model.update(geometry.ice_thickness, geometry.sea_level_elevation, 1,
dt)
topg_0 = model.bed_elevation().numpy()[0, 0]
model.update(geometry.ice_thickness, geometry.sea_level_elevation, 2,
dt)
topg_1 = model.bed_elevation().numpy()[0, 0]
# -4 - 2 == -6 (see the create_forcing() call above)
np.testing.assert_almost_equal(topg_1 - topg_0, -6)
