function error_string = yalmiperror(errorcode,solver)
%YALMIPERROR Creates YALMIP error message based on error code
%
%   s = YALMIPERROR(ID) gives a textual description of an error
%   code generated by YALMIP (typically in SOLVESDP)
%
%   The complete set of error codes are
%
%   -12 Solver license cannot be located
%   -11 Solver license expired
%   -10 NaN in model data
%    -9 Specified solver name not recognized
%    -8 Problem does not satisfy geometric programming rules
%    -7 Solver does not return error codes
%    -6 Search space not bounded (bound all variables)
%    -5 License problems in solver
%    -4 Solver not applicable
%    -3 Solver not found in MATLAB path
%    -2 Successfully solved
%    -1 Unknown error
%     0 Successfully solved
%     1 Infeasible problem
%     2 Unbounded objective function
%     3 Maximum #iterations or time-limit exceeded
%     4 Numerical problems
%     5 Lack of progress
%     6 Initial solution infeasible
%     7 YALMIP sent incorrect input to solver
%     8 Feasibility cannot be determined
%     9 Unknown problem in solver
%    10 bigM failed (obsolete)  
%    11 Other identified error (use savesolveroutput and refer to solver
%    documentation)
%    12 Infeasible or unbounded
%    13 YALMIP cannot determine status in solver
%    14 Model creation failed
%    15 Problem either infeasible or unbounded
%    16 User terminated
%    17 Presolve recovery failed
%    18 Missing non-negativity bounds in GP formulation
%    19 Convexity requirements not met
%    20 Solver complains about bad data
%    21 Failed to initialize bisection space (typically means infeasibility)
%    22 Ill-posed problem according to solver
%
%   See also OPTIMIZE

if nargin ==0
    help yalmiperror
    return
end

if nargin==1
    solver = '';
else
    solver = ['(' strrep(solver,'+','') ')'];
end

switch errorcode
case -12
  error_string = ['Solver license cannot be located ' solver];          
case -11 
  error_string = ['Solver license expired ' solver];          
case -10
  error_string = ['NaN in model data ' solver];          
case -9
  error_string = ['Specified solver name not recognized ' solver];          
case -8
  error_string = ['Problem does not satisfy geometric programming rules'];      
case -7
  error_string = ['Solver does not return error codes ' solver];
case -6
  error_string = ['Search space not bounded ' solver];
case -5 
  error_string = ['License problems in solver ' solver];
 case -4
  error_string = ['Solver not applicable ' solver];    
case -3
  error_string = ['Solver not found ' solver];
 case -2
  error_string = 'No suitable solver';
 case -1
  error_string = ['Unknown error ' solver];
 case 0
  error_string = ['Successfully solved ' solver ];
 case 1
  error_string = ['Infeasible problem ' solver ];
 case 2
  error_string = ['Unbounded objective function ' solver ];
 case 3
  error_string = ['Maximum iterations or time limit exceeded ' solver ];
 case 4
  error_string = ['Numerical problems ' solver ];
 case 5
  error_string = ['Lack of progress ' solver ];
 case 6
  error_string = ['Initial solution infeasible ' solver ];
 case 7
  error_string = ['YALMIP called solver with incorrect input ' solver ];
 case 8
  error_string = ['Feasibility cannot be determined ' solver ];	
 case 9
  error_string = ['Unknown problem in solver (Turn on ''debug'' in sdpsettings) ' solver ];
 case 10
  error_string = ['bigM failed, increase sp.Mfactor ' solver ];
 case 11
  error_string = ['Other identified error ' solver ]; 
 case 12
  error_string = ['Either infeasible or unbounded ' solver ]; 
 case 13
  error_string = ['YALMIP cannot determine status in solver ' solver ]; 
 case 14
  error_string = ['Model creation failed ' solver ]; 
 case 15
  error_string = ['Infeasible or unbounded problem ' solver ]; 
 case 16
  error_string = ['User terminated ' solver ]; 
 case 17
  error_string = ['Presolve recovery failed ' solver ]; 
 case 18
  error_string = ['Missing non-negativity bounds in GP formulation ' solver ];         
 case 19
  error_string = ['Convexity requirements not met ' solver ];           
case 20
  error_string = ['Solver complains about bad data ' solver ];
case 21
  error_string = ['Failed to initialize bisection space (probably infeasible)' solver ];              
case 22
  error_string = ['Ill-posed problem according to solver ' solver ];              
    
 otherwise
end