add_subtract_comp.py

Definition of the Add/Subtract Component.

class openconcept.utilities.math.add_subtract_comp.AddSubtractComp(output_name=None, input_names=None, vec_size=1, length=1, val=1.0, scaling_factors=None, **kwargs)

Bases: ExplicitComponent

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’. Alternatively, a list of ‘vec_size’ can be provided where the entries are all either the same number, or 1. This allows a vector quantity to be multiplied / divided by scalar(s). Use scaling factor -1 for subtraction.

_add_systems

List of equation systems to be initialized with the system.

Type:

list

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

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 Alternatively, if a list, must be all same number, or 1. e.g. [1, 9, 9, 9]. Must be same length as # of inputs

  • 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_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)

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 Alternatively, if a list, must be all same number, or 1. e.g. [1, 9, 9, 9]. Must be same length as # of inputs

  • 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_output()

Use add_equation instead of add_output to define equation systems.

setup()

Set up the addition/subtraction system at run time.

compute(inputs, outputs)

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]