qiskit.optimization.problems.QuadraticObjective¶

class QuadraticObjective(quadratic_program, constant=0.0, linear=None, quadratic=None, sense=<ObjSense.MINIMIZE: 1>)[source]¶

Representation of quadratic objective function of the form: constant + linear * x + x * quadratic * x.

Constructs a quadratic objective function.

Parameters

quadratic_program (Any) – The parent quadratic program.
constant (float) – The constant offset of the objective.
linear (Union[ndarray, spmatrix, List[float], Dict[Union[int, str], float], None]) – The coefficients of the linear part of the objective.
quadratic (Union[ndarray, spmatrix, List[List[float]], Dict[Tuple[Union[int, str], Union[int, str]], float], None]) – The coefficients of the quadratic part of the objective.
sense (ObjSense) – The optimization sense of the objective.

__init__(quadratic_program, constant=0.0, linear=None, quadratic=None, sense=<ObjSense.MINIMIZE: 1>)[source]¶

Constructs a quadratic objective function.

Parameters

quadratic_program (Any) – The parent quadratic program.
constant (float) – The constant offset of the objective.
linear (Union[ndarray, spmatrix, List[float], Dict[Union[int, str], float], None]) – The coefficients of the linear part of the objective.
quadratic (Union[ndarray, spmatrix, List[List[float]], Dict[Tuple[Union[int, str], Union[int, str]], float], None]) – The coefficients of the quadratic part of the objective.
sense (ObjSense) – The optimization sense of the objective.

Methods

`__init__`(quadratic_program[, constant, …])	Constructs a quadratic objective function.
`evaluate`(x)	Evaluate the quadratic objective for given variable values.
`evaluate_gradient`(x)	Evaluate the gradient of the quadratic objective for given variable values.

Attributes

`constant`	Returns the constant part of the objective function.
`linear`	Returns the linear part of the objective function.
`quadratic`	Returns the quadratic part of the objective function.
`quadratic_program`	Returns the parent QuadraticProgram.
`sense`	Returns the sense of the objective function.

property constant¶

Returns the constant part of the objective function.

evaluate(x)[source]¶

Evaluate the quadratic objective for given variable values.

Parameters: x (Union[ndarray, List, Dict[Union[int, str], float]]) – The values of the variables to be evaluated.
Return type: float
Returns: The value of the quadratic objective given the variable values.

evaluate_gradient(x)[source]¶

Evaluate the gradient of the quadratic objective for given variable values.

Parameters: x (Union[ndarray, List, Dict[Union[int, str], float]]) – The values of the variables to be evaluated.
Return type: ndarray
Returns: The value of the gradient of the quadratic objective given the variable values.

property linear¶

Returns the linear part of the objective function.

property quadratic¶

Returns the quadratic part of the objective function.

property quadratic_program¶

Returns the parent QuadraticProgram.

property sense¶

Returns the sense of the objective function.