class BmiHeat(Bmi):
"""Solve the heat equation for a 2D plate."""
_name = 'The 2D Heat Equation'
_input_var_names = ('plate_surface__temperature', )
_output_var_names = ('plate_surface__temperature', )
def __init__(self):
"""Create a BmiHeat model that is ready for initialization."""
self._model = None
self._values = {}
self._var_units = {}
self._grids = {}
self._grid_type = {}
def initialize(self, filename=None):
"""Initialize the Heat model.
Parameters
----------
filename : str, optional
Path to name of input file.
"""
if filename is None:
self._model = Heat()
elif isinstance(filename, types.StringTypes):
with open(filename, 'r') as file_obj:
self._model = Heat.from_file_like(file_obj.read())
else:
self._model = Heat.from_file_like(filename)
self._values = {
'plate_surface__temperature': self._model.temperature,
}
self._var_units = {'plate_surface__temperature': 'K'}
self._grids = {0: ['plate_surface__temperature']}
self._grid_type = {0: 'uniform_rectilinear_grid'}
def update(self):
"""Advance model by one time step."""
self._model.advance_in_time()
def update_frac(self, time_frac):
"""Update model by a fraction of a time step.
Parameters
----------
time_frac : float
Fraction fo a time step.
"""
time_step = self.get_time_step()
self._model.time_step = time_frac * time_step
self.update()
self._model.time_step = time_step
def update_until(self, then):
"""Update model until a particular time.
Parameters
----------
then : float
Time to run model until.
"""
n_steps = (then - self.get_current_time()) / self.get_time_step()
for _ in xrange(int(n_steps)):
self.update()
self.update_frac(n_steps - int(n_steps))
def finalize(self):
"""Finalize model."""
self._model = None
def get_var_type(self, var_name):
"""Data type of variable.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
Returns
-------
str
Data type.
"""
return str(self.get_value_ref(var_name).dtype)
def get_var_units(self, var_name):
"""Get units of variable.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
Returns
-------
str
Variable units.
"""
return self._var_units[var_name]
def get_var_nbytes(self, var_name):
"""Get units of variable.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
Returns
-------
int
Size of data array in bytes.
"""
return self.get_value_ref(var_name).nbytes
def get_var_grid(self, var_name):
"""Grid id for a variable.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
Returns
-------
int
Grid id.
"""
for grid_id, var_name_list in self._grids.items():
if var_name in var_name_list:
return grid_id
def get_grid_rank(self, grid_id):
"""Rank of grid.
Parameters
----------
grid_id : int
Identifier of a grid.
Returns
-------
int
Rank of grid.
"""
return len(self.get_grid_shape(grid_id))
def get_grid_size(self, grid_id):
"""Size of grid.
Parameters
----------
grid_id : int
Identifier of a grid.
Returns
-------
int
Size of grid.
"""
return np.prod(self.get_grid_shape(grid_id))
def get_value_ref(self, var_name):
"""Reference to values.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
Returns
-------
array_like
Value array.
"""
return self._values[var_name]
def get_value(self, var_name):
"""Copy of values.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
Returns
-------
array_like
Copy of values.
"""
return self.get_value_ref(var_name).copy()
def get_value_at_indices(self, var_name, indices):
"""Get values at particular indices.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
indices : array_like
Array of indices.
Returns
-------
array_like
Values at indices.
"""
return self.get_value_ref(var_name).take(indices)
def set_value(self, var_name, src):
"""Set model values.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
src : array_like
Array of new values.
"""
val = self.get_value_ref(var_name)
val[:] = src
def set_value_at_indices(self, var_name, src, indices):
"""Set model values at particular indices.
Parameters
----------
var_name : str
Name of variable as CSDMS Standard Name.
src : array_like
Array of new values.
indices : array_like
Array of indices.
"""
val = self.get_value_ref(var_name)
val.flat[indices] = src
def get_component_name(self):
"""Name of the component."""
return self._name
def get_input_var_names(self):
"""Get names of input variables."""
return self._input_var_names
def get_output_var_names(self):
"""Get names of output variables."""
return self._output_var_names
def get_grid_shape(self, grid_id):
"""Number of rows and columns of uniform rectilinear grid."""
var_name = self._grids[grid_id][0]
return self.get_value_ref(var_name).shape
def get_grid_spacing(self, grid_id):
"""Spacing of rows and columns of uniform rectilinear grid."""
return self._model.spacing
def get_grid_origin(self, grid_id):
"""Origin of uniform rectilinear grid."""
return self._model.origin
def get_grid_type(self, grid_id):
"""Type of grid."""
return self._grid_type[grid_id]
def get_start_time(self):
"""Start time of model."""
return 0.
def get_end_time(self):
"""End time of model."""
#Changed by JLG from
#return np.finfo('d').max
#to the line below.
return 100.
def get_current_time(self):
"""Current time of model."""
return self._model.time
def get_time_step(self):
"""Time step of model."""
return self._model.time_step
