Public API

Weak-dependency extension of CTModels providing JSON3-based serialization.

Loaded automatically when both CTModels and JSON3 are available in the session. Adds methods for CTModels.export_ocp_solution and CTModels.import_ocp_solution dispatching on CTModels.JSON3Tag.

Weak-dependency extension of CTModels providing JLD2-based serialization.

Loaded automatically when both CTModels and JLD2 are available in the session. Adds methods for CTModels.export_ocp_solution and CTModels.import_ocp_solution dispatching on CTModels.JLD2Tag.

Serialization

Serialization module for CTModels.

This module provides functions for importing and exporting optimal control solutions to various formats (JLD2, JSON).

Organisation

• types.jl: Abstract and concrete types for format tags (CTModels.Serialization.AbstractTag, CTModels.Serialization.JLD2Tag, CTModels.Serialization.JSON3Tag)
• export_import.jl: Public API for export/import (CTModels.Serialization.export_ocp_solution, CTModels.Serialization.import_ocp_solution)
• reconstruction_helpers.jl: Internal helpers for solution reconstruction (_reconstruct_solution_from_data, _extract_time_vector)

Public API

The following functions are exported and accessible as CTModels.function_name():

• export_ocp_solution: Export a solution to file
• import_ocp_solution: Import a solution from file

Supported Formats

• JLD2: Binary format (requires JLD2.jl package)
• JSON: Text format (requires JSON3.jl package)

Private API

The following are internal utilities (accessible via Serialization.function_name):

• __format: Get default format
• __filename_export_import: Get default filename

See also: CTModels.Serialization.export_ocp_solution, CTModels.Serialization.import_ocp_solution.

abstract type AbstractTag

Abstract type for export/import functions, used to choose between JSON or JLD extensions.

See also: CTModels.Serialization.JLD2Tag, CTModels.Serialization.JSON3Tag.

struct JLD2Tag <: CTModels.Serialization.AbstractTag

JLD tag for export/import functions.

Fields

No fields (empty struct used as a type tag).

See also: CTModels.Serialization.AbstractTag, CTModels.Serialization.JSON3Tag.

struct JSON3Tag <: CTModels.Serialization.AbstractTag

JSON tag for export/import functions.

Fields

No fields (empty struct used as a type tag).

See also: CTModels.Serialization.AbstractTag, CTModels.Serialization.JLD2Tag.

export_ocp_solution(
    sol::CTModels.Solutions.AbstractSolution;
    format,
    filename
)

Export an optimal control solution to a file.

Arguments

• sol::AbstractSolution: The solution to export.

Keyword Arguments

• format::Symbol=:JLD: Export format, either :JLD or :JSON.
• filename::String="solution": Base filename (extension added automatically).

Returns

• Nothing: This function writes to a file and returns nothing.

Notes

Requires loading the appropriate package (JLD2 or JSON3) before use.

See also: CTModels.Serialization.import_ocp_solution.

export_ocp_solution(
    ::CTModels.Serialization.JSON3Tag,
    sol::CTModels.Solutions.Solution;
    filename
)

Export an optimal control solution to a .json file using the JSON3 format.

This function serializes a CTModels.Solution into a structured JSON dictionary, including all primal and dual information, which can be read by external tools.

Arguments

• ::CTModels.JSON3Tag: A tag used to dispatch the export method for JSON3.
• sol::CTModels.Solution: The solution to be saved.

Keyword Arguments

• filename::String = "solution": Base filename. The .json extension is automatically appended.

Notes

The exported JSON includes the time grid, state, control, costate, objective, solver info, and all constraint duals (if available).

Example

julia> using JSON3
julia> export_ocp_solution(JSON3Tag(), sol; filename="mysolution")
# → creates "mysolution.json"

export_ocp_solution(
    ::CTModels.Serialization.JLD2Tag,
    sol::CTModels.Solutions.Solution;
    filename
)

Export an optimal control solution to a .jld2 file using the JLD2 format.

This function serializes and saves a CTModels.Solution object to disk, allowing it to be reloaded later. The solution is discretized to avoid serialization warnings for function objects.

Arguments

• ::CTModels.JLD2Tag: A tag used to dispatch the export method for JLD2.
• sol::CTModels.Solution: The optimal control solution to be saved.

Keyword Arguments

• filename::String = "solution": Base name of the file. The .jld2 extension is automatically appended.

Example

julia> using JLD2
julia> export_ocp_solution(JLD2Tag(), sol; filename="mysolution")
# → creates "mysolution.jld2"

Notes

• Functions are discretized on the time grid to avoid JLD2 serialization warnings
• The solution can be perfectly reconstructed via import_ocp_solution
• Uses the same discretization logic as JSON export for consistency

import_ocp_solution(
    ocp::CTModels.Models.AbstractModel;
    format,
    filename
) -> CTModels.Solutions.Solution{TimeGridModelType, TimesModelType, StateModelType, ControlModelType, VariableModelType, ModelType, CostateModelType, Float64, DualModelType, CTModels.Solutions.SolverInfos{Any, Dict{Symbol, Any}}} where {TimeGridModelType<:CTModels.Solutions.AbstractTimeGridModel, TimesModelType<:CTModels.Components.AbstractTimesModel, StateModelType<:CTModels.Components.AbstractStateModel, ControlModelType<:CTModels.Components.AbstractControlModel, VariableModelType<:CTModels.Components.AbstractVariableModel, ModelType<:CTModels.Models.AbstractModel, CostateModelType<:Function, DualModelType<:CTModels.Solutions.AbstractDualModel}

Import an optimal control solution from a file.

Arguments

• ocp::AbstractModel: The model associated with the solution.

Keyword Arguments

• format::Symbol=:JLD: Import format, either :JLD or :JSON.
• filename::String="solution": Base filename (extension added automatically).

Returns

• Solution: The imported solution.

Notes

Requires loading the appropriate package (JLD2 or JSON3) before use.

See also: CTModels.Serialization.export_ocp_solution.

import_ocp_solution(
    ::CTModels.Serialization.JSON3Tag,
    ocp::CTModels.Models.Model;
    filename
)

Import an optimal control solution from a .json file exported with export_ocp_solution.

This function reads the JSON contents and reconstructs a CTModels.Solution object, including the discretized primal and dual trajectories.

Arguments

• ::CTModels.JSON3Tag: A tag used to dispatch the import method for JSON3.
• ocp::CTModels.Model: The model associated with the optimal control problem. Used to rebuild the full solution.

Keyword Arguments

• filename::String = "solution": Base filename. The .json extension is automatically appended.

Returns

• CTModels.Solution: A reconstructed solution instance.

Notes

Handles both vector and matrix encodings of signals. If dual fields are missing or null, the corresponding attributes are set to nothing.

Example

julia> using JSON3
julia> sol = import_ocp_solution(JSON3Tag(), model; filename="mysolution")

import_ocp_solution(
    ::CTModels.Serialization.JLD2Tag,
    ocp::CTModels.Models.Model;
    filename
)

Import an optimal control solution from a .jld2 file.

This function loads a previously saved CTModels.Solution from disk and reconstructs it using build_solution from the discretized data.

Arguments

• ::CTModels.JLD2Tag: A tag used to dispatch the import method for JLD2.
• ocp::CTModels.Model: The associated optimal control problem model.

Keyword Arguments

• filename::String = "solution": Base name of the file. The .jld2 extension is automatically appended.

Returns

• CTModels.Solution: The reconstructed solution object.

Example

julia> using JLD2
julia> sol = import_ocp_solution(JLD2Tag(), model; filename="mysolution")

Notes

• The solution is reconstructed from discretized data via build_solution
• This ensures perfect round-trip consistency with the export
• The OCP model from the file is used if the provided one is not compatible