# add_subtract_comp.py¶

Definition of the Add/Subtract Component.

class openmdao.components.add_subtract_comp.AddSubtractComp(output_name=None, input_names=None, vec_size=1, length=1, val=1.0, scaling_factors=None, **kwargs)[source]

Compute a vectorized element-wise addition or subtraction.

Use the add_equation method to define any number of add/subtract relations User defines the names of the input and output variables using add_equation(output_name=’my_output’, input_names=[‘a’,’b’, ‘c’, …])

$result = a * \textrm{scaling factor}_a + b * \textrm{scaling factor}_b + c * \textrm{scaling factor}_c + ...$
where all inputs shape (vec_size, n)
b is of shape (vec_size, n) c is of shape (vec_size, n) result is of shape (vec_size, n)

All input vectors must be of the same shape, specified by the options ‘vec_size’ and ‘length’. Use scaling factor -1 for subtraction.

__init__(output_name=None, input_names=None, vec_size=1, length=1, val=1.0, scaling_factors=None, **kwargs)[source]

Allow user to create an addition/subtracton system with one-liner.

Parameters: output_name : str (required) name of the result variable in this component’s namespace. input_names : iterable of str (required) names of the input variables for this system vec_size : int Length of the first dimension of the input and output vectors (i.e number of rows, or vector length for a 1D vector) Default is 1 length : int Length of the second dimension of the input and ouptut vectors (i.e. number of columns) Default is 1 which results in input/output vectors of size (vec_size,) scaling_factors : iterable of numeric Scaling factors to apply to each input. Use [1,1,…] for addition, [1,-1,…] for subtraction Must be same length as input_names Default is None which results in a scaling factor of 1 on each input (element-wise addition) val : float or list or tuple or ndarray The initial value of the variable being added in user-defined units. Default is 1.0. **kwargs : str Any other arguments to pass to the addition system (same as add_output method for ExplicitComponent) Examples include units (str or None), desc (str)
add_constraint(name, lower=None, upper=None, equals=None, ref=None, ref0=None, adder=None, scaler=None, indices=None, linear=False, parallel_deriv_color=None, vectorize_derivs=False, cache_linear_solution=False)

Add a constraint variable to this system.

Parameters: name : string Name of the response variable in the system. lower : float or ndarray, optional Lower boundary for the variable upper : float or ndarray, optional Upper boundary for the variable equals : float or ndarray, optional Equality constraint value for the variable ref : float or ndarray, optional Value of response variable that scales to 1.0 in the driver. ref0 : float or ndarray, optional Value of response variable that scales to 0.0 in the driver. adder : float or ndarray, optional Value to add to the model value to get the scaled value. Adder is first in precedence. scaler : float or ndarray, optional value to multiply the model value to get the scaled value. Scaler is second in precedence. indices : sequence of int, optional If variable is an array, these indicate which entries are of interest for this particular response. These may be positive or negative integers. linear : bool Set to True if constraint is linear. Default is False. parallel_deriv_color : string If specified, this design var will be grouped for parallel derivative calculations with other variables sharing the same parallel_deriv_color. vectorize_derivs : bool If True, vectorize derivative calculations. cache_linear_solution : bool If True, store the linear solution vectors for this variable so they can be used to start the next linear solution with an initial guess equal to the solution from the previous linear solve.

Notes

The response can be scaled using ref and ref0. The argument ref0 represents the physical value when the scaled value is 0. The argument ref represents the physical value when the scaled value is 1.

add_design_var(name, lower=None, upper=None, ref=None, ref0=None, indices=None, adder=None, scaler=None, parallel_deriv_color=None, vectorize_derivs=False, cache_linear_solution=False)

Add a design variable to this system.

Parameters: name : string Name of the design variable in the system. lower : float or ndarray, optional Lower boundary for the param upper : upper or ndarray, optional Upper boundary for the param ref : float or ndarray, optional Value of design var that scales to 1.0 in the driver. ref0 : float or ndarray, optional Value of design var that scales to 0.0 in the driver. indices : iter of int, optional If a param is an array, these indicate which entries are of interest for this particular design variable. These may be positive or negative integers. adder : float or ndarray, optional Value to add to the model value to get the scaled value. Adder is first in precedence. scaler : float or ndarray, optional value to multiply the model value to get the scaled value. Scaler is second in precedence. parallel_deriv_color : string If specified, this design var will be grouped for parallel derivative calculations with other variables sharing the same parallel_deriv_color. vectorize_derivs : bool If True, vectorize derivative calculations. cache_linear_solution : bool If True, store the linear solution vectors for this variable so they can be used to start the next linear solution with an initial guess equal to the solution from the previous linear solve.

Notes

The response can be scaled using ref and ref0. The argument ref0 represents the physical value when the scaled value is 0. The argument ref represents the physical value when the scaled value is 1.

add_discrete_input(name, val, desc='')

Add a discrete input variable to the component.

Parameters: name : str name of the variable in this component’s namespace. val : a picklable object The initial value of the variable being added. desc : str description of the variable dict metadata for added variable
add_discrete_output(name, val, desc='')

Add an output variable to the component.

Parameters: name : str name of the variable in this component’s namespace. val : a picklable object The initial value of the variable being added. desc : str description of the variable. dict metadata for added variable
add_equation(output_name, input_names, vec_size=1, length=1, val=1.0, units=None, res_units=None, desc='', lower=None, upper=None, ref=1.0, ref0=0.0, res_ref=None, scaling_factors=None)[source]

Add an addition/subtraction relation.

Parameters: output_name : str (required) name of the result variable in this component’s namespace. input_names : iterable of str (required) names of the input variables for this system vec_size : int Length of the first dimension of the input and output vectors (i.e number of rows, or vector length for a 1D vector) Default is 1 length : int Length of the second dimension of the input and ouptut vectors (i.e. number of columns) Default is 1 which results in input/output vectors of size (vec_size,) scaling_factors : iterable of numeric Scaling factors to apply to each input. Use [1,1,…] for addition, [1,-1,…] for subtraction Must be same length as input_names Default is None which results in a scaling factor of 1 on each input (element-wise addition) val : float or list or tuple or ndarray The initial value of the variable being added in user-defined units. Default is 1.0. units : str or None Units in which the output variables will be provided to the component during execution. Default is None, which means it has no units. res_units : str or None Units in which the residuals of this output will be given to the user when requested. Default is None, which means it has no units. desc : str description of the variable. lower : float or list or tuple or ndarray or Iterable or None lower bound(s) in user-defined units. It can be (1) a float, (2) an array_like consistent with the shape arg (if given), or (3) an array_like matching the shape of val, if val is array_like. A value of None means this output has no lower bound. Default is None. upper : float or list or tuple or ndarray or or Iterable None upper bound(s) in user-defined units. It can be (1) a float, (2) an array_like consistent with the shape arg (if given), or (3) an array_like matching the shape of val, if val is array_like. A value of None means this output has no upper bound. Default is None. ref : float or ndarray Scaling parameter. The value in the user-defined units of this output variable when the scaled value is 1. Default is 1. ref0 : float or ndarray Scaling parameter. The value in the user-defined units of this output variable when the scaled value is 0. Default is 0. res_ref : float or ndarray Scaling parameter. The value in the user-defined res_units of this output’s residual when the scaled value is 1. Default is 1.
add_input(name, val=1.0, shape=None, src_indices=None, flat_src_indices=None, units=None, desc='')

Add an input variable to the component.

Parameters: name : str name of the variable in this component’s namespace. val : float or list or tuple or ndarray or Iterable The initial value of the variable being added in user-defined units. Default is 1.0. shape : int or tuple or list or None Shape of this variable, only required if src_indices not provided and val is not an array. Default is None. src_indices : int or list of ints or tuple of ints or int ndarray or Iterable or None The global indices of the source variable to transfer data from. A value of None implies this input depends on all entries of source. Default is None. The shapes of the target and src_indices must match, and form of the entries within is determined by the value of ‘flat_src_indices’. flat_src_indices : bool If True, each entry of src_indices is assumed to be an index into the flattened source. Otherwise each entry must be a tuple or list of size equal to the number of dimensions of the source. units : str or None Units in which this input variable will be provided to the component during execution. Default is None, which means it is unitless. desc : str description of the variable dict metadata for added variable
add_objective(name, ref=None, ref0=None, index=None, adder=None, scaler=None, parallel_deriv_color=None, vectorize_derivs=False, cache_linear_solution=False)

Add a response variable to this system.

Parameters: name : string Name of the response variable in the system. ref : float or ndarray, optional Value of response variable that scales to 1.0 in the driver. ref0 : float or ndarray, optional Value of response variable that scales to 0.0 in the driver. index : int, optional If variable is an array, this indicates which entry is of interest for this particular response. This may be a positive or negative integer. adder : float or ndarray, optional Value to add to the model value to get the scaled value. Adder is first in precedence. scaler : float or ndarray, optional value to multiply the model value to get the scaled value. Scaler is second in precedence. parallel_deriv_color : string If specified, this design var will be grouped for parallel derivative calculations with other variables sharing the same parallel_deriv_color. vectorize_derivs : bool If True, vectorize derivative calculations. cache_linear_solution : bool If True, store the linear solution vectors for this variable so they can be used to start the next linear solution with an initial guess equal to the solution from the previous linear solve.

Notes

The objective can be scaled using scaler and adder, where

$x_{scaled} = scaler(x + adder)$

or through the use of ref/ref0, which map to scaler and adder through the equations:

\begin{align}\begin{aligned}0 = scaler(ref_0 + adder)\\1 = scaler(ref + adder)\end{aligned}\end{align}

which results in:

\begin{align}\begin{aligned}adder = -ref_0\\scaler = \frac{1}{ref + adder}\end{aligned}\end{align}
add_output()[source]

Use add_equation instead of add_output to define equation systems.

add_recorder(recorder, recurse=False)

Add a recorder to the driver.

Parameters: recorder : A recorder instance. recurse : boolean Flag indicating if the recorder should be added to all the subsystems.
add_response(name, type_, lower=None, upper=None, equals=None, ref=None, ref0=None, indices=None, index=None, adder=None, scaler=None, linear=False, parallel_deriv_color=None, vectorize_derivs=False, cache_linear_solution=False)

Add a response variable to this system.

The response can be scaled using ref and ref0. The argument ref0 represents the physical value when the scaled value is 0. The argument ref represents the physical value when the scaled value is 1.

Parameters: name : string Name of the response variable in the system. type_ : string The type of response. Supported values are ‘con’ and ‘obj’ lower : float or ndarray, optional Lower boundary for the variable upper : upper or ndarray, optional Upper boundary for the variable equals : equals or ndarray, optional Equality constraint value for the variable ref : float or ndarray, optional Value of response variable that scales to 1.0 in the driver. ref0 : upper or ndarray, optional Value of response variable that scales to 0.0 in the driver. indices : sequence of int, optional If variable is an array, these indicate which entries are of interest for this particular response. index : int, optional If variable is an array, this indicates which entry is of interest for this particular response. adder : float or ndarray, optional Value to add to the model value to get the scaled value. Adder is first in precedence. scaler : float or ndarray, optional value to multiply the model value to get the scaled value. Scaler is second in precedence. linear : bool Set to True if constraint is linear. Default is False. parallel_deriv_color : string If specified, this design var will be grouped for parallel derivative calculations with other variables sharing the same parallel_deriv_color. vectorize_derivs : bool If True, vectorize derivative calculations. cache_linear_solution : bool If True, store the linear solution vectors for this variable so they can be used to start the next linear solution with an initial guess equal to the solution from the previous linear solve.
check_config(logger)

Perform optional error checks.

Parameters: logger : object The object that manages logging output.
cleanup()

Clean up resources prior to exit.

compute(inputs, outputs)[source]

Compute the element wise addition or subtraction of inputs using numpy + operator.

Parameters: inputs : Vector unscaled, dimensional input variables read via inputs[key] outputs : Vector unscaled, dimensional output variables read via outputs[key]
compute_jacvec_product(inputs, d_inputs, d_outputs, mode)

Compute jac-vector product. The model is assumed to be in an unscaled state.

If mode is:

‘fwd’: d_inputs |-> d_outputs

‘rev’: d_outputs |-> d_inputs

Parameters: inputs : Vector unscaled, dimensional input variables read via inputs[key] d_inputs : Vector see inputs; product must be computed only if var_name in d_inputs d_outputs : Vector see outputs; product must be computed only if var_name in d_outputs mode : str either ‘fwd’ or ‘rev’
compute_partials(inputs, partials)

Compute sub-jacobian parts. The model is assumed to be in an unscaled state.

Parameters: inputs : Vector unscaled, dimensional input variables read via inputs[key] partials : Jacobian sub-jac components written to partials[output_name, input_name]
declare_partials(of, wrt, dependent=True, rows=None, cols=None, val=None, method='exact', step=None, form=None, step_calc=None)

Declare information about this component’s subjacobians.

Parameters: of : str or list of str The name of the residual(s) that derivatives are being computed for. May also contain a glob pattern. wrt : str or list of str The name of the variables that derivatives are taken with respect to. This can contain the name of any input or output variable. May also contain a glob pattern. dependent : bool(True) If False, specifies no dependence between the output(s) and the input(s). This is only necessary in the case of a sparse global jacobian, because if ‘dependent=False’ is not specified and declare_partials is not called for a given pair, then a dense matrix of zeros will be allocated in the sparse global jacobian for that pair. In the case of a dense global jacobian it doesn’t matter because the space for a dense subjac will always be allocated for every pair. rows : ndarray of int or None Row indices for each nonzero entry. For sparse subjacobians only. cols : ndarray of int or None Column indices for each nonzero entry. For sparse subjacobians only. val : float or ndarray of float or scipy.sparse Value of subjacobian. If rows and cols are not None, this will contain the values found at each (row, col) location in the subjac. method : str The type of approximation that should be used. Valid options include: ‘fd’: Finite Difference, ‘cs’: Complex Step, ‘exact’: use the component defined analytic derivatives. Default is ‘exact’. step : float Step size for approximation. Defaults to None, in which case the approximation method provides its default value. form : string Form for finite difference, can be ‘forward’, ‘backward’, or ‘central’. Defaults to None, in which case the approximation method provides its default value. step_calc : string Step type for finite difference, can be ‘abs’ for absolute’, or ‘rel’ for relative. Defaults to None, in which case the approximation method provides its default value.
distributed

Provide ‘distributed’ property for backwards compatibility.

Returns: bool reference to the ‘distributed’ option.
get_constraints(recurse=True)

Get the Constraint settings from this system.

Retrieve the constraint settings for the current system as a dict, keyed by variable name.

Parameters: recurse : bool, optional If True, recurse through the subsystems and return the path of all constraints relative to the this system. dict The constraints defined in the current system.
get_design_vars(recurse=True, get_sizes=True)

Get the DesignVariable settings from this system.

Retrieve all design variable settings from the system and, if recurse is True, all of its subsystems.

Parameters: recurse : bool If True, recurse through the subsystems and return the path of all design vars relative to the this system. get_sizes : bool, optional If True, compute the size of each response. dict The design variables defined in the current system and, if recurse=True, its subsystems.
get_linear_vectors(vec_name='linear')

Return the linear inputs, outputs, and residuals vectors.

Parameters: vec_name : str Name of the linear right-hand-side vector. The default is ‘linear’. (inputs, outputs, residuals) : tuple of instances Yields the inputs, outputs, and residuals linear vectors for vec_name.
get_nonlinear_vectors()

Return the inputs, outputs, and residuals vectors.

Returns: (inputs, outputs, residuals) : tuple of instances Yields the inputs, outputs, and residuals nonlinear vectors.
get_objectives(recurse=True)

Get the Objective settings from this system.

Retrieve all objectives settings from the system as a dict, keyed by variable name.

Parameters: recurse : bool, optional If True, recurse through the subsystems and return the path of all objective relative to the this system. dict The objectives defined in the current system.
get_responses(recurse=True, get_sizes=True)

Get the response variable settings from this system.

Retrieve all response variable settings from the system as a dict, keyed by variable name.

Parameters: recurse : bool, optional If True, recurse through the subsystems and return the path of all responses relative to the this system. get_sizes : bool, optional If True, compute the size of each response. dict The responses defined in the current system and, if recurse=True, its subsystems.
initialize()[source]

Declare options.

Parameters: complex : Boolean Set True to enable complex math (e.g. for complex step verification)
is_active()

Determine if the system is active on this rank.

Returns: bool If running under MPI, returns True if this System has a valid communicator. Always returns True if not running under MPI.
linear_solver

Get the linear solver for this system.

list_inputs(values=True, units=False, hierarchical=True, print_arrays=False, out_stream=<object object>)

Return and optionally log a list of input names and other optional information.

If the model is parallel, only the local variables are returned to the process. Also optionally logs the information to a user defined output stream. If the model is parallel, the rank 0 process logs information about all variables across all processes.

Parameters: values : bool, optional When True, display/return input values. Default is True. units : bool, optional When True, display/return units. Default is False. hierarchical : bool, optional When True, human readable output shows variables in hierarchical format. print_arrays : bool, optional When False, in the columnar display, just display norm of any ndarrays with size > 1. The norm is surrounded by vertical bars to indicate that it is a norm. When True, also display full values of the ndarray below the row. Format is affected by the values set with numpy.set_printoptions Default is False. out_stream : file-like object Where to send human readable output. Default is sys.stdout. Set to None to suppress. list list of input names and other optional information about those inputs
list_outputs(explicit=True, implicit=True, values=True, prom_name=False, residuals=False, residuals_tol=None, units=False, shape=False, bounds=False, scaling=False, hierarchical=True, print_arrays=False, out_stream=<object object>)

Return and optionally log a list of output names and other optional information.

If the model is parallel, only the local variables are returned to the process. Also optionally logs the information to a user defined output stream. If the model is parallel, the rank 0 process logs information about all variables across all processes.

Parameters: explicit : bool, optional include outputs from explicit components. Default is True. implicit : bool, optional include outputs from implicit components. Default is True. values : bool, optional When True, display/return output values. Default is True. prom_name : bool, optional When True, display/return the promoted name of the variable. Default is False. residuals : bool, optional When True, display/return residual values. Default is False. residuals_tol : float, optional If set, limits the output of list_outputs to only variables where the norm of the resids array is greater than the given ‘residuals_tol’. Default is None. units : bool, optional When True, display/return units. Default is False. shape : bool, optional When True, display/return the shape of the value. Default is False. bounds : bool, optional When True, display/return bounds (lower and upper). Default is False. scaling : bool, optional When True, display/return scaling (ref, ref0, and res_ref). Default is False. hierarchical : bool, optional When True, human readable output shows variables in hierarchical format. print_arrays : bool, optional When False, in the columnar display, just display norm of any ndarrays with size > 1. The norm is surrounded by vertical bars to indicate that it is a norm. When True, also display full values of the ndarray below the row. Format is affected by the values set with numpy.set_printoptions Default is False. out_stream : file-like Where to send human readable output. Default is sys.stdout. Set to None to suppress. list list of output names and other optional information about those outputs
ln_solver

Get the linear solver for this system.

metadata

Get the options for this System.

nl_solver

Get the nonlinear solver for this system.

nonlinear_solver

Get the nonlinear solver for this system.

reconfigure()

Perform reconfiguration.

Returns: bool If True, reconfiguration is to be performed.
record_iteration()

Record an iteration of the current System.

resetup(setup_mode='full')

Public wrapper for _setup that reconfigures after an initial setup has been performed.

Parameters: setup_mode : str Must be one of ‘full’, ‘reconf’, or ‘update’.
run_apply_linear(vec_names, mode, scope_out=None, scope_in=None)

Compute jac-vec product.

This calls _apply_linear, but with the model assumed to be in an unscaled state.

Parameters: vec_names : [str, …] list of names of the right-hand-side vectors. mode : str ‘fwd’ or ‘rev’. scope_out : set or None Set of absolute output names in the scope of this mat-vec product. If None, all are in the scope. scope_in : set or None Set of absolute input names in the scope of this mat-vec product. If None, all are in the scope.
run_apply_nonlinear()

Compute residuals.

This calls _apply_nonlinear, but with the model assumed to be in an unscaled state.

run_linearize(sub_do_ln=True)

Compute jacobian / factorization.

This calls _linearize, but with the model assumed to be in an unscaled state.

Parameters: sub_do_ln : boolean Flag indicating if the children should call linearize on their linear solvers.
run_solve_linear(vec_names, mode)

Apply inverse jac product.

This calls _solve_linear, but with the model assumed to be in an unscaled state.

Parameters: vec_names : [str, …] list of names of the right-hand-side vectors. mode : str ‘fwd’ or ‘rev’. boolean Failure flag; True if failed to converge, False is successful. float relative error. float absolute error.
run_solve_nonlinear()

Compute outputs.

This calls _solve_nonlinear, but with the model assumed to be in an unscaled state.

Returns: boolean Failure flag; True if failed to converge, False is successful. float relative error. float absolute error.
set_check_partial_options(wrt, method='fd', form=None, step=None, step_calc=None)

Set options that will be used for checking partial derivatives.

Parameters: wrt : str or list of str The name or names of the variables that derivatives are taken with respect to. This can contain the name of any input or output variable. May also contain a glob pattern. method : str Method for check: “fd” for finite difference, “cs” for complex step. form : str Finite difference form for check, can be “forward”, “central”, or “backward”. Leave undeclared to keep unchanged from previous or default value. step : float Step size for finite difference check. Leave undeclared to keep unchanged from previous or default value. step_calc : str Type of step calculation for check, can be “abs” for absolute (default) or “rel” for relative. Leave undeclared to keep unchanged from previous or default value.
set_initial_values()

Set all input and output variables to their declared initial values.

setup()[source]

Set up the addition/subtraction system at run time.

system_iter(include_self=False, recurse=True, typ=None)

Yield a generator of local subsystems of this system.

Parameters: include_self : bool If True, include this system in the iteration. recurse : bool If True, iterate over the whole tree under this system. typ : type If not None, only yield Systems that match that are instances of the given type.