gemseo / core

coupling_structure module

Graph-based analysis of the weak and strong couplings between several disciplines.

class gemseo.core.coupling_structure.MDOCouplingStructure(disciplines)[source]

Bases: object

Structure of the couplings between several disciplines.

The methods of this class include the computation of weak, strong or all couplings.

Parameters

disciplines (Sequence[gemseo.core.discipline.MDODiscipline]) – The disciplines that possibly exchange coupling variables.

Return type

None

find_discipline(output)[source]

Find which discipline produces a given output.

Parameters

output (str) – The name of an output.

Returns

The discipline producing this output, if it exists.

Raises

  • TypeError – If the name of the output is not a string.

  • ValueError – If the output is not an output of the discipline.

Return type

gemseo.core.discipline.MDODiscipline

get_input_couplings(discipline, strong=True)[source]

Compute all the input coupling variables of a discipline.

Parameters
Returns

The names of the input coupling variables.

Return type

list[str]

get_output_couplings(discipline, strong=True)[source]

Compute the output coupling variables of a discipline, either strong or weak.

Parameters
Returns

The names of the output coupling variables.

Return type

list[str]

get_strongly_coupled_disciplines(add_self_coupled=True, by_group=False)[source]

Determines the strongly coupled disciplines, that is the disciplines that occur in (possibly different) MDAs.

Parameters

  • add_self_coupled (bool) –

    if True, adds the disciplines that are self-coupled to the list of strongly coupled disciplines

    By default it is set to True.

  • by_group (bool) –

    if True, returns a list of list of strongly coupled diciplines where the sublists contains the groups of disciplines that are strongly coupled together. if False, returns a single list

    By default it is set to False.

Returns

The coupled disciplines list or list of list

Return type

list[MDODiscipline] | list[list[MDODiscipline]]

static is_self_coupled(discipline)[source]

Test if the discipline is self-coupled.

Self-coupling means that one of its outputs is also an input.

Parameters

discipline (gemseo.core.discipline.MDODiscipline) – The discipline.

Returns

Whether the discipline is self-coupled.

Return type

bool

plot_n2_chart(file_path='n2.pdf', show_data_names=True, save=True, show=False, fig_size=(15.0, 10.0), open_browser=False)[source]

Generate a dynamic N2 chart for the disciplines, and possibly a static one.

A static N2 chart is a figure generated with the matplotlib library that can be saved to file_path, displayed on screen or both; the extension of file_path must be recognized by matplotlib.

A dynamic N2 chart is a HTML file with interactive features such as reordering the disciplines, expanding or collapsing the groups of strongly coupled disciplines and displaying information on disciplines or couplings.

Parameters

  • file_path (str | Path) –

    The file path to save the static N2 chart.

    By default it is set to n2.pdf.

  • show_data_names (bool) –

    Whether to show the names of the coupling data ; otherwise, circles are drawn, whose size depends on the number of coupling names.

    By default it is set to True.

  • save (bool) –

    Whether to save the static N2 chart.

    By default it is set to True.

  • show (bool) –

    Whether to display the static N2 chart on screen.

    By default it is set to False.

  • fig_size (tuple[float, float]) –

    The width and height of the static N2 chart in inches.

    By default it is set to (15.0, 10.0).

  • open_browser (bool) –

    Whether to display the interactive N2 chart in a browser.

    By default it is set to False.

Raises

ValueError – When there is less than two disciplines.

Return type

None

property all_couplings: list[str]

The inputs of disciplines that are also ouputs of other disciplines.

disciplines: Sequence[gemseo.core.discipline.MDODiscipline]

The disciplines.

graph: gemseo.core.dependency_graph.DependencyGraph

The directed graph of the disciplines.

sequence: list[list[tuple[gemseo.core.discipline.MDODiscipline]]]

The sequence of execution of the disciplines.

property strong_couplings: list[str]

The outputs of the strongly coupled disciplines that are also inputs of a strongly coupled discipline.

property strongly_coupled_disciplines: list[gemseo.core.discipline.MDODiscipline]

The disciplines that are strongly coupled, ie that lie in cycles in the coupling graphs.

property weak_couplings: list[str]

The outputs of the weakly coupled disciplines.

property weakly_coupled_disciplines: list[gemseo.core.discipline.MDODiscipline]

The disciplines that do not appear in cycles in the coupling graph.