ellipsoids_init(varargin)

function out = ellipsoids_init(varargin)
% 
% ELLIPSOIDS_INIT - initializes Ellipsoidal Toolbox.
% 
% Any routine of Ellipsoidal Toolbox can be called with user-specified values
% of different parameters. To make Ellipsoidal Toolbox as user-friendly as
% possible, we provide the option to store default values of the parameters
% in variable ellOptions, which is stored in MATLAB's workspace as a global
% variable (i.e. it stays there unless one types 'clear all'). 
%

  global ellOptions;


  ellOptions.version = '1.1.2';
  ellOptions.verbose = 1; % verbosity 1 ==> ON, 0 ==> OFF
  if ellOptions.verbose > 0
    fprintf('Initializing Ellipsoidal Toolbox version %s ...\n', ellOptions.version);
  end


  ellOptions.abs_tol = 1e-7; % absolute tolerance
  ellOptions.rel_tol = 1e-6; % relative tolerance


  % ODE solver parameters.
  ellOptions.time_grid          = 200;   % density of the time grid
  ellOptions.ode_solver         = 1;     % 1 ==> RK45, 2 ==> RK23, 3 ==> Adams
  ellOptions.norm_control       = 'on';  % on/off norm control in ODE solver
  ellOptions.ode_solver_options = 0;     % 0 - default, 1 - user-defined
  
  
  % Solver for nonlinear optimization problem with nonlinear constraints:
  %        Minimize:   f(x)
  %        Subject to: g(x) <= 0, h(x) = 0.
  % Used for distance calculation.
  % nlcp_solver = 0 - use the solver that comes with Ellipsoidal Toolbox.
  % nlcp_solver = 1 - use the routines from MATLAB Optimization Toolbox.
  ellOptions.nlcp_solver = 0;


  ellOptions.plot2d_grid = 200; % grid density for plotting in 2D
  ellOptions.plot3d_grid = 200; % grid density for plotting in 3D


  % YALMIP settings.
  try
    ellOptions.sdpsettings = sdpsettings('Verbose', 0, 'warning', 0, 'cachesolvers', 1);
  catch
    warning('YALMIP not found, some functionality may be not accessible.');
    ellOptions.sdpsettings = [];
  end

  return;