qiskit.algorithms.optimizers.SNOBFIT
class SNOBFIT(maxiter=1000, maxfail=10, maxmp=None, verbose=False)
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_level | Returns bounds support level |
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 |
setting | Return 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_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