% This function is part of the NMSM Pipeline, see file for full license.
%
% This function reads the optimal control settings (GPOPS-II based) from a
% separate XML file.
%
% (struct) -> (Array of string)
% Optimal control solver settings are loaded
function solverSettings = getOptimalControlSolverSettings(settingsFileName)
solverSettingsTree = xml2struct(settingsFileName);
solverSettings.optimizationFileName = 'trackingOptimizationOutputFile.txt';
solverSettings.derivativeSupplier = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_derivatives_supplier', 'sparseFD'));
solverSettings.derivativeLevel = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_derivatives_level', 'first'));
solverSettings.derivativeDependencies = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_derivatives_dependencies', 'sparse'));
solverSettings.scaleMethods = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_scales_method', 'none'));
solverSettings.method = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_method', 'RPM-Differentiation'));
solverSettings.meshMethod = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_method', 'hp-PattersonRao'));
solverSettings.meshTolerance = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_tolerance', '10e-3')));
solverSettings.meshMaxIterations = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_max_iterations', '10')));
solverSettings.meshColpointsMin = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_colpoints_min', '3')));
solverSettings.meshColpointsMax = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_colpoints_max', '10')));
solverSettings.meshSplitMult = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_splitmult', '1.2')));
solverSettings.meshCurveRatio = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_curveratio', '2')));
solverSettings.meshR = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_R', '1.2')));
solverSettings.meshSigma = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_sigma', '0.5')));
solverSettings.numCollocationPoints = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_phase_intervals', '6')));
solverSettings.numIntervals = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_mesh_phase_colpoints_per_Interval', '10')));
solverSettings.solverType = getTextFromField(getFieldByNameOrAlternate( ...
solverSettingsTree, 'setup_nlp_solver', 'ipopt'));
solverSettings.linearSolverType = getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_nlp_linear_solver', 'ma57'));
solverSettings.solverTolerance = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_nlp_tolerance', '1e-3')));
solverSettings.stepSize = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_nlp_step_size', '1e-8')));
solverSettings.maxIterations = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_nlp_max_iterations', '2e4')));
solverSettings.displayLevel = str2double(getTextFromField( ...
getFieldByNameOrAlternate(solverSettingsTree, 'setup_display_level', '2')));
solverSettings.integralBound = str2double( ...
parseElementTextByNameOrAlternate(solverSettingsTree, "integral_bound", "1"));
end