gemseo / algos

design_space module¶

Design space¶

A design space is used to represent the optimization’s unknowns, a.k.a. design variables. A DesignSpace describes this design space at a given state, in terms of names, sizes, types, bounds and current values of the design variables. Variables can easily be added to the DesignSpace using the DesignSpace.add_variable() method or removed using the DesignSpace.remove_variable() method. We can also filter the design variables using the DesignSpace.filter() method. Getters and setters are also available to get or set the value of a given variable property. Lastly, an instance of DesignSpace can be stored in a txt or HDF file.

Classes:

DesignSpace([hdf_file])

Class that describes the design space at a given state:

class gemseo.algos.design_space.DesignSpace(hdf_file=None)[source]¶

Bases: object

Class that describes the design space at a given state:

the names/sizes/types/bounds of the variables and the initial solution of the optimization problem

Constructor.

Attributes:

`AVAILABLE_TYPES`
`DESIGN_SPACE_GROUP`
`FLOAT`
`INTEGER`
`LB_GROUP`
`MINIMAL_FIELDS`
`NAMES_GROUP`
`NAME_GROUP`
`SEP`
`SIZE_GROUP`
`TABLE_NAMES`
`TYPE_GROUP`
`UB_GROUP`
`VALUE_GROUP`
`VAR_TYPE_GROUP`

Methods:

`add_variable`(name[, size, var_type, l_b, …])	Add a variable to the design space.
`array_to_dict`(x_array)	Split the current point into a dictionary with variables names.
`check`()	Check the state of the design space.
`check_membership`(x_vect[, variables_names])	Checks whether the input variables satisfy the design space requirements.
`dict_to_array`(x_dict[, all_vars, all_var_list])	Aggregate a point as dictionary into array.
`export_hdf`(file_path[, append])	Export to hdf file.
`export_to_txt`(output_file[, fields, header_char])	Exports the design space to a text file.
`extend`(other)	Extend the design space with another design space.
`filter`(keep_variables[, copy])	Filter the design space to keep a sublist of variables.
`filter_dim`(variable, keep_dimensions)	Filters the design space to keep a sublist of dimensions for a given variable.
`get_active_bounds`([x_vec, tol])	Determine which bound constraints of the current point are active.
`get_current_x`([variables_names])	Gets the current point in the design space.
`get_current_x_dict`()	Get the current point in the design space.
`get_current_x_normalized`()	Returns the current point normalized.
`get_indexed_var_name`(variable_name)	Return a list of the variables names with their indices such as.
`get_indexed_variables_names`()	Return a list of the variables names with their indices such as.
`get_lower_bound`(name)	Gets the lower bound of a variable.
`get_lower_bounds`([variables_names])	Generates an array of the variables’ lower bounds.
`get_pretty_table`([fields])	Builds a PrettyTable object from the design space data.
`get_size`(name)	Get the size of a variable Return None if the variable is not known.
`get_type`(name)	Get the type of a variable Return None if the variable is not known.
`get_upper_bound`(name)	Gets the upper bound of a variable.
`get_upper_bounds`([variables_names])	Generates an array of the variables’ upper bounds.
`get_variables_indexes`(variables_names)	Return the indexes of a design array corresponding to the variables names.
`has_current_x`()	Tests if current_x is defined.
`import_hdf`(file_path)	Imports design space from hdf file.
`normalize_vect`(x_vect[, minus_lb])	Normalizes a vector of the design space.
`project_into_bounds`(x_c[, normalized])	Projects x_c onto the bounds, using a simple coordinate wise approach.
`read_from_txt`(input_file[, header])	Parses a csv file to read the DesignSpace.
`remove_variable`(name)	Remove a variable (and bounds and types) from the design space.
`round_vect`(x_vect)	Rounds the vector where variables are of integer type.
`set_current_variable`(name, current_value)	Set the current value of a single variable.
`set_current_x`(current_x)	Set the current point.
`set_lower_bound`(name, lower_bound)	Set a new lower bound for variable name.
`set_upper_bound`(name, upper_bound)	Set a new upper bound for variable name.
`to_complex`()	Casts the current value to complex.
`unnormalize_vect`(x_vect[, minus_lb, no_check])	Unnormalizes a normalized vector of the design space.

AVAILABLE_TYPES = ['float', 'integer']¶

DESIGN_SPACE_GROUP = 'design_space'¶

FLOAT = 'float'¶

INTEGER = 'integer'¶

LB_GROUP = 'l_b'¶

MINIMAL_FIELDS = ['name', 'lower_bound', 'upper_bound']¶

NAMES_GROUP = 'names'¶

NAME_GROUP = 'name'¶

SEP = '!'¶

SIZE_GROUP = 'size'¶

TABLE_NAMES = ['name', 'lower_bound', 'value', 'upper_bound', 'type']¶

TYPE_GROUP = 'type'¶

UB_GROUP = 'u_b'¶

VALUE_GROUP = 'value'¶

VAR_TYPE_GROUP = 'var_type'¶

add_variable(name, size=1, var_type='float', l_b=None, u_b=None, value=None)[source]¶

Add a variable to the design space.

Parameters

name – param size: (Default value = 1)
var_type – Default value = FLOAT)
l_b – Default value = None)
u_b – Default value = None)
value – Default value = None)
size – (Default value = 1)

array_to_dict(x_array)[source]¶

Split the current point into a dictionary with variables names.

Parameters: x_array – x array to be converted to a dict of array

check()[source]¶: Check the state of the design space.

check_membership(x_vect, variables_names=None)[source]¶

Checks whether the input variables satisfy the design space requirements.

Parameters

x_vect (dict or array) – design variables
variables_names – names of the variables to be checked

dict_to_array(x_dict, all_vars=True, all_var_list=None)[source]¶

Aggregate a point as dictionary into array.

Parameters

x_dict – point as dictionary
all_vars – if True, all variables shall be in x_dict
all_var_list – list of whole set of variables, if None, use self.variables_names

export_hdf(file_path, append=False)[source]¶

Export to hdf file.

Parameters

file_path – path to file to write
append – if True, appends the data in the file

export_to_txt(output_file, fields=None, header_char='', **table_options)[source]¶

Exports the design space to a text file.

Parameters

output_file – output file path
fields – list of fields to export, by default all

extend(other)[source]¶

Extend the design space with another design space.

Parameters: other (DesignSpace) – design space to be appended

filter(keep_variables, copy=False)[source]¶

Filter the design space to keep a sublist of variables.

Parameters

keep_variables (str of list(str)) – the list of variables to keep
copy (bool) – if True then a copy of the design space is filtered, otherwise the design space itself is filtered

Returns

the filtered design space (or a copy)

Return type

DesignSpace

filter_dim(variable, keep_dimensions)[source]¶

Filters the design space to keep a sublist of dimensions for a given variable.

Parameters

variable – the variable
keep_dimensions – the list of dimension to keep

get_active_bounds(x_vec=None, tol=1e-08)[source]¶

Determine which bound constraints of the current point are active.

Parameters

x_vec – the point at which we check the bounds
tol – tolerance of comparison of a scalar with a bound (Default value = 1e-8)

get_current_x(variables_names=None)[source]¶

Gets the current point in the design space.

Parameters: variables_names (list(str)) – names of the required variables, optional
Returns: the x vector as array
Return type: ndarray

get_current_x_dict()[source]¶

Get the current point in the design space.

Returns: the x vector as a dict, keys are the variable names values are the variable vales as np array

get_current_x_normalized()[source]¶

Returns the current point normalized.

Returns: the x vector as array normalized by the bounds

get_indexed_var_name(variable_name)[source]¶

Return a list of the variables names with their indices such as.

[x!0,x!1,y,z!0,z!1]

Parameters: variable_name (str) – name of the variable
Returns: names of the variable components
Return type: list(str)

get_indexed_variables_names()[source]¶

Return a list of the variables names with their indices such as.

[x!0,x!1,y,z!0,z!1]

Returns: names of all the variables components
Return type: list(str)

get_lower_bound(name)[source]¶

Gets the lower bound of a variable.

Parameters: name – variable name
Returns: variable lower bound (possibly infinite)

get_lower_bounds(variables_names=None)[source]¶

Generates an array of the variables’ lower bounds.

Parameters: variables_names – names of the variables of which the lower bounds are required

get_pretty_table(fields=None)[source]¶

Builds a PrettyTable object from the design space data.

Parameters: fields – list of fields to export, by default all
Returns: the pretty table object

get_size(name)[source]¶

Get the size of a variable Return None if the variable is not known.

Parameters: name – name of the variable

get_type(name)[source]¶

Get the type of a variable Return None if the variable is not known.

Parameters: name – name of the variable

get_upper_bound(name)[source]¶

Gets the upper bound of a variable.

Parameters: name – variable name
Returns: variable upper bound (possibly infinite)

get_upper_bounds(variables_names=None)[source]¶

Generates an array of the variables’ upper bounds.

Parameters: variables_names – names of the variables of which the upper bounds are required

get_variables_indexes(variables_names)[source]¶

Return the indexes of a design array corresponding to the variables names.

Parameters: variables_names (list(str)) – names of the variables
Returns: indexes of a design array corresponding to the variables names
Return type: ndarray

has_current_x()[source]¶

Tests if current_x is defined.

Returns: True if current_x is defined

import_hdf(file_path)[source]¶

Imports design space from hdf file.

Parameters: file_path –

normalize_vect(x_vect, minus_lb=True)[source]¶

Normalizes a vector of the design space. Unbounded variables are not normalized.

Parameters

x_vect (ndarray) – design variables
minus_lb – if True, remove lower bounds at normalization

Returns

normalized vector

project_into_bounds(x_c, normalized=False)[source]¶

Projects x_c onto the bounds, using a simple coordinate wise approach.

Parameters

normalized (bool) – if True then the vector is assumed to be normalized
x_c – x vector (np array)

Returns

projected x_c

static read_from_txt(input_file, header=None)[source]¶

Parses a csv file to read the DesignSpace.

Parameters

input_file – returns: s: the design space
header – fields list, or by default, read in the file

Returns

the design space

remove_variable(name)[source]¶

Remove a variable (and bounds and types) from the design space.

Parameters: name – name of the variable to remove

round_vect(x_vect)[source]¶

Rounds the vector where variables are of integer type.

Parameters: x_vect – design variables to round

set_current_variable(name, current_value)[source]¶

Set the current value of a single variable.

Parameters

name – name of the variable
current_value – current value of the variable

set_current_x(current_x)[source]¶

Set the current point.

Parameters: current_x – the current design vector

set_lower_bound(name, lower_bound)[source]¶

Set a new lower bound for variable name.

Parameters

name – name of the variable
lower_bound – lower bound

set_upper_bound(name, upper_bound)[source]¶

Set a new upper bound for variable name.

Parameters

name – name of the variable
upper_bound – upper bound

to_complex()[source]¶: Casts the current value to complex.

unnormalize_vect(x_vect, minus_lb=True, no_check=False)[source]¶

Unnormalizes a normalized vector of the design space.

Parameters

x_vect (ndarray) – design variables
minus_lb – if True, remove lower bounds at normalization
no_check – if True, don’t check that values are in [0,1]

Returns

normalized vector