engforge.problem_context.Problem

class Problem(system, kw_dict=None, Xnew=None, ctx_fail_new=False, **opts)

Bases: ProblemExec, DataframeMixin

Initializes the ProblemExec.

#TODO: exit system should abide by update / signals options

#TODO: provide data storage options for dataframe / table storage history/ record keeping (ss vs transient data)

#TODO: create an option to copy the system and run operations on it, and options for applying the state from the optimized copy to the original system

Parameters:

• system – The system to be executed.

• Xnew – The new state of the system to set at the start o the problem context, and will revert after the problem exits, optional

• ctx_fail_new – Whether to raise an error if no execution context is available, use in utility methods ect. Default is False.

• kw_dict – A keyword argument dictionary to be parsed for solver options, and removed from the outer context. Changes are made to this dictionary, so they are removed automatically from the outer context, and thus no longer passed to interior vars.

• dxdt – The dynamics integration method. Default is None meaning that dynamic vars are not considered for minimization unless otherwise specified. Steady State can be specified by dxdt=0 all dynamic vars are considered as solver variables, with the constraint that their rate of change is zero. If a dictionary is passed then the dynamic vars are considered as solver variables, with the constraint that their rate of change is equal to the value in the dictionary, and all other unspecified rates are zero (steady).

#### Solver Selection Options :param combos: The selection of combos. Default is ‘*’ (select all). :param ign_combos: The combos to be ignored. :param only_combos: The combos to be selected. :param add_obj: Whether to add an objective to the solver. Default is True. :param slv_vars: The selection of solvables. Default is ‘*’ (select all). :param add_vars: The solvables to be added to the solver. :param ign_vars: The solvables to be ignored. :param only_vars: The solvables to be selected. :param only_active: Whether to select only active items. Default is True. :param activate: The solvables to be activated. :param deactivate: The solvables to be deactivated. :param fail_revert: Whether to raise an error if no solvables are selected. Default is True. :param revert_last: Whether to revert the last change. Default is True. :param revert_every: Whether to revert every change. Default is True. :param exit_on_failure: Whether to exit on failure, or continue on. Default is True.

Methods

activate_temp_state
apply_post_signals	applies all post signals
apply_pre_signals	applies all pre signals
change_sys_var	use this function to change the value of a system var and update the start state, multiple uses in the same context will not change the record preserving the start value
clean_context
cls_is_active	checks if the cache has a session
critical
debug
debug_levels	debug the levels of the context
discard_contexts	discard all contexts
error
error_action	handles the error action wrt to the problem
establish_system	caches the system references, and parses the system arguments
exit_action	handles the exit action wrt system
exit_and_revert
exit_to_level
exit_with_state
filter_vars	selects only settable refs
format_columns
full_refresh	a more time consuming but throughout refresh of the system
get_extra_kws	extracts the combo input from the kwargs
get_parent_key	returns the parent key of the key
get_ref_values	returns the values of the refs
get_sesh	get the session
handle_solution
info
integral_rate	provides the dynamic rate of the system at time t, and state x
integrate
min_refresh	what things need to be refreshed per execution, this is important whenever items are replaced
msg
parse_default	splits strings or lists and returns a list of options for the key, if nothing found returns None if fail set to True raises an exception, otherwise returns the default value
persist_contexts	convert all contexts to a new storage format
pos_obj	converts an objective to a positive value
post_execute	Updates the post/both signals after the solver has been executed.
post_update_system	updates the system
pre_execute	Updates the pre/both signals after the solver has been executed.
print_all_info	Print all the information of each component's dictionary.
refresh_references	refresh the system references
reset_contexts	reset all contexts to a new storage format
reset_data	reset the data storage
revert_to_start
save_data	save data to the context
set_checkpoint	sets the checkpoint
set_ref_values	returns the values of the refs
set_time
smart_split_dataframe	splits dataframe between constant values and variants
solve_min	Solve the minimization problem using the given vars and constraints.
sys_solver_constraints	formatted as arguments for the solver
sys_solver_objectives	gathers variables from solver vars, and attempts to locate any input_vars to add as well.
update_dynamics
update_methods
update_system	updates the system
warning

Attributes

all_components	returns all variables in the system
all_comps	returns all variables in the system
all_comps_and_vars
all_problem_vars	solver variables + dynamics states when dynamic_solve is True
all_system_references
all_variable_refs
all_variables	returns all variables in the system
attr_inst
attribute_sys_key_map	key mapping to lookup the key from the attribute
check_dynamics
copy_system
dataframe	returns the dataframe of the system
dataframe_constants
dataframe_variants
dynamic_comps
dynamic_rate
dynamic_rate_eq
dynamic_solve	indicates if the system is dynamic
dynamic_state
enter_refresh
entered
exit_on_failure
exited
fail_revert
final_objectives	returns the final objective of the system, depending on mixed objective, equalities, and constraints
full_update
identity
integrator_rate_refs	combine the dynamic state and the integrator rates to get the transient state of the system, but convert their keys to the target var names
integrator_rates
integrator_var_refs	combine the dynamic state and the integrator rates to get the transient state of the system, but convert their keys to the target var names
integrator_vars
integrators
is_active	checks if the context has been entered and not exited
kwargs	copy of slv_kw args
level_name
level_number
log_level
numeric_data	return a list of sorted data rows by item and filter each row to remove invalid data
opt_fail
output_state	records the state of the system
post_callback
post_exec
pre_exec
problem_eq
problem_id
problem_ineq
problem_input
problem_objs
problem_opt_vars	solver variables
problems_dict
raise_on_unknown
record_state	records the state of the system using session
ref_attrs
revert_every
revert_last
run_solver
save_mode
save_on_exit
sesh	caches the property for the session
session_id
signal_inst
signals
signals_source
signals_target
skip_plot_vars	accesses '_skip_plot_vars' if it exists, otherwise returns empty list
solveable	checks the system's references to determine if its solveabl
solver_inst
success_thresh
system
session
x_start

property all_components: dict

returns all variables in the system

property all_comps: dict

returns all variables in the system

property all_problem_vars: dict

solver variables + dynamics states when dynamic_solve is True

property all_variables: dict

returns all variables in the system

apply_post_signals()

applies all post signals

apply_pre_signals()

applies all pre signals

property attribute_sys_key_map: dict

key mapping to lookup the key from the attribute

Type:

returns an attribute

change_sys_var(key, value, refs=None, doset=True, attr_key_map=None)

use this function to change the value of a system var and update the start state, multiple uses in the same context will not change the record preserving the start value

Parameters:

key – a string corresponding to a ref, or an attrs.Attribute of one of the system or its component’s.

class_cache

alias of ProblemExec

classmethod cls_is_active()

checks if the cache has a session

property dataframe: DataFrame

returns the dataframe of the system

debug_levels()

debug the levels of the context

discard_contexts()

discard all contexts

property dynamic_solve: bool

indicates if the system is dynamic

error_action(error)

handles the error action wrt to the problem

establish_system(system, kw_dict, **kwargs)

caches the system references, and parses the system arguments

exit_action()

handles the exit action wrt system

filter_vars(refs)

selects only settable refs

Parameters:

refs (list)

property final_objectives: dict

returns the final objective of the system, depending on mixed objective, equalities, and constraints

full_refresh(sesh=None)

a more time consuming but throughout refresh of the system

classmethod get_extra_kws(kwargs, _check_keys={'activate': None, 'add_obj': True, 'add_vars': None, 'both_match': True, 'combos': 'default', 'deactivate': None, 'dxdt': None, 'ign_combos': None, 'ign_vars': None, 'obj': None, 'only_active': True, 'only_combos': None, 'only_vars': None, 'slv_vars': '*', 'weights': None}, rmv=False, use_defaults=True)

extracts the combo input from the kwargs

Parameters:

_check_keys (dict)

get_parent_key(key, look_back_num=1)

returns the parent key of the key

get_ref_values(refs=None)

returns the values of the refs

get_sesh(sesh=None)

get the session

integral_rate(t, x, dt, Xss=None, Yobj=None, **kw)

provides the dynamic rate of the system at time t, and state x

property integrator_rate_refs

combine the dynamic state and the integrator rates to get the transient state of the system, but convert their keys to the target var names

property integrator_var_refs

combine the dynamic state and the integrator rates to get the transient state of the system, but convert their keys to the target var names

property is_active

checks if the context has been entered and not exited

property kwargs

copy of slv_kw args

min_refresh(sesh=None)

what things need to be refreshed per execution, this is important whenever items are replaced

property numeric_data

return a list of sorted data rows by item and filter each row to remove invalid data

property output_state: dict

records the state of the system

classmethod parse_default(key, defaults, input_dict, rmv=False, empty_str=True)

splits strings or lists and returns a list of options for the key, if nothing found returns None if fail set to True raises an exception, otherwise returns the default value

persist_contexts()

convert all contexts to a new storage format

pos_obj(ref)

converts an objective to a positive value

post_execute(*args, **kwargs)

Updates the post/both signals after the solver has been executed. This is useful for updating the system state after the solver has been executed.

post_update_system(*args, **kwargs)

updates the system

pre_execute(*args, **kwargs)

Updates the pre/both signals after the solver has been executed. This is useful for updating the system state after the solver has been executed.

print_all_info(keys=None, comps=None)

Print all the information of each component’s dictionary. Parameters: key_sch (str, optional): A pattern to match dictionary keys. Only keys matching this pattern will be included in the output. comps (list, optional): A list of component sys names to filter. Only information of these components will be printed. Returns: None (except stdout :)

Parameters:

• keys (str | None)

• comps (str | None)

property problem_opt_vars: dict

solver variables

property record_state: dict

records the state of the system using session

refresh_references(sesh=None)

refresh the system references

reset_contexts(fail_if_discardmode=True)

reset all contexts to a new storage format

reset_data()

reset the data storage

save_data(index=None, force=False, **add_data)

save data to the context

property sesh

caches the property for the session

set_checkpoint()

sets the checkpoint

set_ref_values(values, refs=None, scope='sref')

returns the values of the refs

property skip_plot_vars: list

accesses ‘_skip_plot_vars’ if it exists, otherwise returns empty list

smart_split_dataframe(df=None, split_groups=0, key_f=<function <lambda>>)

splits dataframe between constant values and variants

solve_min(Xref=None, Yref=None, output=None, **kw)

Solve the minimization problem using the given vars and constraints. And sets the system state to the solution depending on input of the following:

Solve the root problem using the given vars. :type Xref: :param Xref: The reference input values. :type Yref: :param Yref: The reference objective values to minimize. :type output: :param output: The output dictionary to store the results. (default: None) :param fail: Flag indicating whether to raise an exception if the solver doesn’t converge. (default: True) :type kw: :param kw: Additional keyword arguments. :return: The output dictionary containing the results.

property solveable

checks the system’s references to determine if its solveabl

sys_solver_constraints(add_con=None, combo_filter=True, **kw)

formatted as arguments for the solver

sys_solver_objectives(**kw)

gathers variables from solver vars, and attempts to locate any input_vars to add as well. use exclude_vars to eliminate a variable from the solver

update_system(*args, **kwargs)

updates the system