The SolverInfo function provides information about a specific optimizer engine, or about a previously-defined LP, QP or NLP. Its declaration is:

SolverInfo( lp : optional LP_TYPE ; item : atomic text ; engine : optional atomic text ; 
            ref : optional boolean = False )

Where:

lp : A problem instance previously defined by LpDefine, QpDefine or NlpDefine, LpRead, or returned by FindIIS.
item : A description of the desired item(s). Case insensitive. See below for possible values.
engine: The name of a Solver engine.
ref : A flag indicating whether a reference to the result should be returned.

Obtaining Information about a Problem Instance

You can obtain information about a previously-defined optimization problem using the two-parameter form of SolverInfo:

 SolverInfo( lp, item )

For example, to get the variable lower bounds use:

 SolverInfo( lp, "lb" )

Possible values for the Item are

"Item"	Valid For	Dimensionality	Type	Description
"objcoef"	LP, QP	Vars	numeric
"Q"	QP	Vars, Vars2	numeric
"lhs"	LP, QP	Vars, Constraints	numeric
"rhs"	LP,QP,NLP	Constraints	numeric
"constraintUb"	LP,QP,NLP	Constraints	numeric	Upper bound for each constraint
"constraintLb"	LP,QP,NLP	Constraints	numeric	Lower bound for each constraint
"lb"	LP,QP,NLP	Vars	numeric
"sense"	LP,QP,NLP	Constraints	'>=','<=', or '='
"ub"	LP,QP,NLP	Vars	numeric
"ctype"	LP,QP,NLP	Vars	'C', 'I', or 'B'
"maximize"	LP,QP,NLP	atomic	True, False
"engine"	LP,QP,NLP	atomic	text
"setting"	LP,QP,NLP	local .Parameter	numeric
"type"	LP,QP,NLP	atomic	"LP","QP", "QCP" or "NLP"
"vars"	LP,QP,NLP	Vars	elements of the Vars index
"constraints"	LP,QP,NLP	Constraints	the constraint names

If any of these Items are specified, but the lp parameter is not provided, an error results.

Obtaining Information about a Solver Engine

The usage:

SolverInfo( engine: atomic text ; Item : atomic text )

returns information about a solver engine. The possible values for Item in this usage are:

Item	Dimensionality	Type	Description
"Setting"	List	numeric	Array of control setting names.
"MaxSetting"	Local .Parameter	numeric	upper bounds for setting
"MinSetting"	Local .Parameter	numeric	lower bounds for setting
"Name"	atomic	text	The engine name
"DLL"	atomic	text	File path to solver engine's DLL
"TrialPeriod"	atomic	numeric	number of days until Frontline solver trial license expires
"MaxVars"	atomic	numeric	Maximum number of decision variables supported by engine
"MaxIntVars"	atomic	numeric	Maximum number of integer variables supported by engine
"MaxConstraints"	atomic	numeric	Maximum number of constraints supported by engine
"MaxVarBounds"	atomic	numeric	Maximum number of variable bounds supported by engine.
"Milliseconds"	atomic	numeric	Time spent in computation.
"Iterations"	atomic	numeric	# of iterations engine has performed
"Calls"	atomic	numeric	# of function evaluations that have occurred
"Jacobians"	atomic	numeric	# of jacobians evaluations that have occurred
"Hessians"	atomic	numeric	# of hessians evaluations that have occurred

If the Engine parameter is omitted, but the Lp parameter is present, then the setting for the engine used by the Lp is returned. If both the LP and Engine parameters are specified, then these settings will be returned for the specified Engine (in the case that these differ).

General Information

Some information can be obtained without specifying any problem instance or engine using the syntax, e.g.:

SolverInfo( Items: "AvailEngines" )

The possible Items not pertaining to any engine or problem instance are:

Item	Dimensionality	Type	Description
"AvailEngines"	List	Text	The names the Solver engines available for use.

Obtaining Multiple Items in a Single Call

Multiple items can be obtained from SolverInfo in a single call by array abstracting over the Item parameter. For example:

Index SettingInfo := ["Name","Max","Min","Value"]
Variable TheSettings := SolverInfo( Lp:the_lp, Item: SettingInfo )

This example would return two dimensional array indexed by SettingInfo and by a local index named .Parameters.

Since many of the possible Item values return results with different dimensionality, using the function in this way would cause the dimensionalities to be combined undesirably. Thus, when obtaining items having different dimensionality in a single call, the ref parameter can be set to true, and a reference to each setting is returned. For example, the following would compute slack:

var info := SolverInfo( lp, Item: ["lhs","rhs"], Ref:true );
var x := LpSolution(lp);
#info[.Parameter="rhs"] - sum( #info[.Parameter='lhs'] * x, Vars )