Difference between revisions of "OptStatusText"

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''[[New to Analtyica 4.3]].  For earlier releases, this was called [[LpStatusText]].''
 
''[[New to Analtyica 4.3]].  For earlier releases, this was called [[LpStatusText]].''
  
= OptStatusText(prog) =
+
= OptStatusText(opt) =
  
 
When you attempt to solve an optimization problem, either linear, quadratic, non-linear, or mixed-integer varieties of these, it is important to check the status that results.  Calling [[OptStatusText]] ensures that the optimization search has taken place, and returns an English-language description of the status, usually indicating the condition that led to the termination of the search.  The «prog» is an optimization problem specification returned by a call to [[DefineOptimization]].
 
When you attempt to solve an optimization problem, either linear, quadratic, non-linear, or mixed-integer varieties of these, it is important to check the status that results.  Calling [[OptStatusText]] ensures that the optimization search has taken place, and returns an English-language description of the status, usually indicating the condition that led to the termination of the search.  The «prog» is an optimization problem specification returned by a call to [[DefineOptimization]].

Revision as of 23:40, 10 February 2011


New to Analtyica 4.3. For earlier releases, this was called LpStatusText.

OptStatusText(opt)

When you attempt to solve an optimization problem, either linear, quadratic, non-linear, or mixed-integer varieties of these, it is important to check the status that results. Calling OptStatusText ensures that the optimization search has taken place, and returns an English-language description of the status, usually indicating the condition that led to the termination of the search. The «prog» is an optimization problem specification returned by a call to DefineOptimization.

The OptStatusNum function provides a numeric code corresponding to the status, while OptStatusText returns an English-language description. Be aware that the set of codes has changed in Analytica 4.0 from the set of possible codes returned in Analytica 3.1, as a result of an upgrade to Frontline System's newer and restructured solver library.

The following table needs to be cleaned up here, but provides a listing of the possible text that can be returned from LpStatusText. See also OptStatusNum for the numeric values. This should be re-organized here into a two column table, with LpStatusNum in the first column (as an integer) and OptStatusText in the second.

	case Optimize_Status_Invalid:		return "Invalid status"; 
	case Optimize_Status_Ignore:		return "Ignore status. Used when dummy result code needs to be overridden.";
	case Optimize_Status_Lic_Problem:	return "Invalid license status. (License expired, missing, invalid, etc.)";
	case Optimize_Status_Optimal:		return "Optimal solution has been found.";
	case Optimize_Status_Converged:		return "The Solver has converged to the current solution.";
	case Optimize_Status_No_Remedies:	return "No remedies: All remedies failed to find better point.";
	case Optimize_Status_Iterate_Limit:	return "Iterates limit reached. Indicates an early exit of the algorithm.";
	case Optimize_Status_Unbounded:		return "Optimizing an unbounded objective function.";
	case Optimize_Status_Unfeasible:	return "Feasible solution could not be found.";
	case Optimize_Status_User_Abort:	return "Optimization aborted by user.";
	case Optimize_Status_Linear_Invalid:return "Invalid linear model. Returned when a linearity assumption renders incorrect.";
	case Optimize_Status_Bad_Dataset:	return "Bad data set status. Returned when a problem data set renders inconsistent.";
	case Optimize_Status_Float_Err:		return "Float error status. (Internal float error.)";
	case Optimize_Status_Time_Out:		return "Time out status. Returned when the maximum allowed time has been exceeded. Indicates an early exit of the algorithm.";
	case Optimize_Status_Memory_Dearth:	return "Memory dearth status. Returned when the system cannot allocate enough memory to perform the optimization.";
	case Optimize_Status_Interpret_Err: return "Interpretation error. (Parser, Diagnostics, or Executor error.)";
	case Optimize_Status_Api_Err:		return "Fatal API error. (API not responding.)";
	case Optimize_Status_Incumb_Cand:	return "The Solver has found an integer solution within integer tolerance.";
	case Optimize_Status_Bbnode_Limit:	return "Branching and bounding node limit reached.";
	case Optimize_Status_Bbmips_Limit:	return "Branching and bounding maximum number of incumbent points reached.";
	case Optimize_Status_Probable:		return "Probable global optimum reached. Returned when MSL (Bayesian) global optimality test has been satisfied.";
	case Optimize_Status_Bounds_Missing:return "Missing bounds status. Returned for EV/MSL Require Bounds when bounds are missing.";
	case Optimize_Status_Bounds_Conflict: return "Bounds conflict status. Indicates = >= bounds conflict with existing binary or alldifferent constraints.";
	case Optimize_Status_Bounds_Inconsist: return "Bounds inconsistency status. Returned when the lower bound value of a variable is grater than the upper bound value, i.e. lb[i] > ub[i] for some variable bound i.";
	case Optimize_Status_Derivative_Err:return "Derivative error. Returned when API_Jacobian has not been able to compute gradients.";
	case Optimize_Status_Cone_Overlap:	return "Cone overlap status. Returned when a variable appears in more than one cone.";
	case Optimize_Status_Exception:		return "Exception occurred status. Returned when an exception has been caught by try/catch top-level. Optimize_Status_Custom_Base 1000 Custom base status. (Base for Solver Engine custom results.)";
	case 1101:							return "No problem information is available"; // custom SOCP error code, should never occur in the SDK, but could occur in Excel version
	case 1102:							return "The quadratic constraints are non-convex.  The SOCP engine cannot solve this problem.";
	default:
		return "unknown Frontline solver status code";

Custom or add-on solver engines may return additional status codes not listed here. In these cases, OptStatusText will generally return "unknown Frontline solver status code", but OptStatusNum will vary.

Add-on solver engines may issue OptStatusNum codes greater than or equal to 1000. These are not unique, with the error message depending on the particular solver engine.

See Also

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