PEtabSelect: Save/Load global pets struct

By saving the global struct "pets", the history and state of model selection is not lost when the model selection terminates
The pets struct can be recovered by calling arPetsLoad

arFramework3/PEtabSelect/arPetsLoad.m

@@ -0,0 +1,29 @@
+function arPetsLoad(name, PetsOutputDir)
+% ARPETSLOAD loads the PEtab Select struct "pets" from file.
+%
+% The python module petab_select cannot be saved to/loaded from a .mat file
+% Therefore, only the relevant fields are saved and loaded.
+%
+% INPUT:
+%   name: Name of the file to load the struct from.
+%   PetsOutputDir: Directory to load the file from.
+%
+% SEE: arPetsSave
+
+arguments
+    name char = 'petsSave';
+    PetsOutputDir char = fullfile(pwd(), 'PEtabSelect', 'Results');
+end
+
+% initialize new pets struct
+arPetsInitModule;
+
+% load the struct from file
+loadPath = fullfile(PetsOutputDir, name);
+load(loadPath, "petsSave");
+
+% assign the filed to the global variable
+pets.history = petsSave.history;
+pets.problem = petsSave.problem;
+
+end

arFramework3/PEtabSelect/arPetsSave.m

@@ -0,0 +1,30 @@
+function arPetsSave(name, PetsOutputDir)
+% ARPETSSAVE saves the PEtab Select struct "pets" to file.
+%
+% The python module petab_select cannot be saved to/loaded from a .mat file
+% Therefore, only the relevant fields are saved and loaded.
+%
+% INPUT:
+%   name: Name of the file to save the struct to.
+%   PetsOutputDir: Directory to save the file to.
+%
+% SEE: arPetsLoad
+
+arguments
+    name char = 'petsSave';
+    PetsOutputDir char = fullfile(pwd(), 'PEtabSelect', 'Results');
+end
+
+% access the global pets struct
+global pets
+
+% create a struct with the relevant fields
+petsSave = struct();
+petsSave.history = pets.history;
+petsSave.problem = pets.problem;
+
+% save the struct to file
+savePath = fullfile(PetsOutputDir, name);
+save(savePath, "petsSave")
+
+end

arFramework3/PEtabSelect/arPetsSelectModel.m

@@ -130,6 +130,9 @@ function arPetsSelectModel(PetsProblemFile, options)
 % create output directory
 [~] = mkdir(options.PetsOutputDir);
 
+% save the PEtab Select struct to file
+arPetsSave('petsSave', options.PetsOutputDir);
+
 % get the overall best model and save it to yaml file
 final_model = get_best(pets.problem, pets.problem.state.models);
 final_model.to_yaml(fullfile(options.PetsOutputDir, 'selected_model.yaml'));