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qiskit.aqua.components.optimizers.SNOBFIT

class SNOBFIT(maxiter=1000, maxfail=10, maxmp=None, verbose=False)

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Stable Noisy Optimization by Branch and FIT algorithm.

SnobFit is used for the optimization of derivative-free, noisy objective functions providing robust and fast solutions of problems with continuous variables varying within bound.

Uses skquant.opt installed with pip install scikit-quant. For further detail, please refer to https://github.com/scikit-quant/scikit-quant and https://qat4chem.lbl.gov/software.

Parameters

  • maxiter (int) – Maximum number of function evaluations.
  • maxmp (Optional[int]) – Maximum number of model points requested for the local fit. Default = 2 * number of parameters + 6 set to this value when None.
  • maxfail (int) – Maximum number of failures to improve the solution. Stops the algorithm after maxfail is reached.
  • verbose (bool) – Provide verbose (debugging) output.

Raises

MissingOptionalLibraryError – scikit-quant or SQSnobFit not installed

__init__

__init__(maxiter=1000, maxfail=10, maxmp=None, verbose=False)

Parameters

  • maxiter (int) – Maximum number of function evaluations.
  • maxmp (Optional[int]) – Maximum number of model points requested for the local fit. Default = 2 * number of parameters + 6 set to this value when None.
  • maxfail (int) – Maximum number of failures to improve the solution. Stops the algorithm after maxfail is reached.
  • verbose (bool) – Provide verbose (debugging) output.

Raises

MissingOptionalLibraryError – scikit-quant or SQSnobFit not installed


Methods

__init__([maxiter, maxfail, maxmp, verbose])type maxiterint
get_support_level()Returns support level dictionary.
gradient_num_diff(x_center, f, epsilon[, …])We compute the gradient with the numeric differentiation in the parallel way, around the point x_center.
optimize(num_vars, objective_function[, …])Runs the optimization.
print_options()Print algorithm-specific options.
set_max_evals_grouped(limit)Set max evals grouped
set_options(**kwargs)Sets or updates values in the options dictionary.
wrap_function(function, args)Wrap the function to implicitly inject the args at the call of the function.

Attributes

bounds_support_levelReturns bounds support level
gradient_support_levelReturns gradient support level
initial_point_support_levelReturns initial point support level
is_bounds_ignoredReturns is bounds ignored
is_bounds_requiredReturns is bounds required
is_bounds_supportedReturns is bounds supported
is_gradient_ignoredReturns is gradient ignored
is_gradient_requiredReturns is gradient required
is_gradient_supportedReturns is gradient supported
is_initial_point_ignoredReturns is initial point ignored
is_initial_point_requiredReturns is initial point required
is_initial_point_supportedReturns is initial point supported
settingReturn setting

bounds_support_level

Returns bounds support level

get_support_level

get_support_level()

Returns support level dictionary.

gradient_num_diff

static gradient_num_diff(x_center, f, epsilon, max_evals_grouped=1)

We compute the gradient with the numeric differentiation in the parallel way, around the point x_center.

Parameters

  • x_center (ndarray) – point around which we compute the gradient
  • f (func) – the function of which the gradient is to be computed.
  • epsilon (float) – the epsilon used in the numeric differentiation.
  • max_evals_grouped (int) – max evals grouped

Returns

the gradient computed

Return type

grad

gradient_support_level

Returns gradient support level

initial_point_support_level

Returns initial point support level

is_bounds_ignored

Returns is bounds ignored

is_bounds_required

Returns is bounds required

is_bounds_supported

Returns is bounds supported

is_gradient_ignored

Returns is gradient ignored

is_gradient_required

Returns is gradient required

is_gradient_supported

Returns is gradient supported

is_initial_point_ignored

Returns is initial point ignored

is_initial_point_required

Returns is initial point required

is_initial_point_supported

Returns is initial point supported

optimize

optimize(num_vars, objective_function, gradient_function=None, variable_bounds=None, initial_point=None)

Runs the optimization.

print_options()

Print algorithm-specific options.

set_max_evals_grouped

set_max_evals_grouped(limit)

Set max evals grouped

set_options

set_options(**kwargs)

Sets or updates values in the options dictionary.

The options dictionary may be used internally by a given optimizer to pass additional optional values for the underlying optimizer/optimization function used. The options dictionary may be initially populated with a set of key/values when the given optimizer is constructed.

Parameters

kwargs (dict) – options, given as name=value.

setting

Return setting

wrap_function

static wrap_function(function, args)

Wrap the function to implicitly inject the args at the call of the function.

Parameters

  • function (func) – the target function
  • args (tuple) – the args to be injected

Returns

wrapper

Return type

function_wrapper

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