inst/HiGHS/docs/src/structures/enums.md

In highs: 'HiGHS' Optimization Solver

Enums

The members of the fundamental HiGHS enums are defined below. If Enum refers to a particular enum, and Member to a particular member, the members are available as follows.

• Python: highspy.Enum.Member
• C++: Enum::Member

Members for internal use only are not documented.

HighsStatus

This is (part of) the return value of most HiGHS methods:

• kError: The method has exposed an error
• kOk: The method has completed successfully
• kWarning: The method has recovered from an unusual event, or has terminated due to reaching a time or iteration limit

MatrixFormat

This defines the format of a HighsSparseMatrix:

• kColwise: The matrix is stored column-wise
• kRowwise: The matrix is stored row-wise

ObjSense

This defines optimization sense of a HighsLp:

• kMinimize: The objective is to be minimized
• kMaximize: The objective is to be maximized

HighsVarType

This defines the feasible values of a variable within a model:

• kContinuous: The variable can take continuous values between its bounds
• kInteger: The variable must take integer values between its bounds
• kSemiContinuous: The variable must be zero or take continuous values between its bounds
• kSemiInteger: The variable must be zero or take integer values between its bounds

HessianFormat

This defines the format of a HighsHessian:

• kTriangular: The lower triangular component of the Hessian is stored column-wise or, equivalently, the upper triangular component is stored row-wise
• kSquare: The whole Hessian Q is stored column-wise. This is for input only: internally the lower triangular component of (Q+Q^T)/2 will be stored

SolutionStatus

This defines the nature of any primal or dual solution information:

• kSolutionStatusNone: There is no solution information
• kSolutionStatusInfeasible: The solution is not feasible
• kSolutionStatusFeasible: The solution is feasible

BasisValidity

This defines the nature of any basis information:

• kBasisValidityInvalid: There is no basisn information
• kBasisValidityValid: The basis information is valid

HighsModelStatus

This defines the status of the model after a call to run

• kNotset: The model status has not been set
• kModelError: There is an error in the model
• kSolveError: There has been an error when solving the model
• kModelEmpty: The model is empty
• kOptimal: The model has been solved to optimality
• kInfeasible: The model is infeasible
• kUnboundedOrInfeasible: The model is unbounded or infeasible
• kUnbounded: The model is unbounded
• kObjectiveBound: The bound on the model objective value has been reached
• kObjectiveTarget: The target value for the model objective has been reached
• kTimeLimit: The run time limit has been reached
• kIterationLimit: The iteration limit has been reached
• kSolutionLimit: The MIP solver has reached the limit on the number of LPs solved
• kInterrupt: The solver has been interrupted by the user
• kMemoryLimit: The solver has been unable to allocate sufficient memory
• kUnknown: The model status is unknown

HighsBasisStatus

This defines the status of a variable (or slack variable for a constraint) in a basis:

• kLower: The variable is nonbasic at its lower bound (or fixed value)
• kBasic: The variable is basic
• kUpper: The variable is at its upper bound
• kZero: A free variable is nonbasic and set to zero
• kNonbasic: The variable is nonbasic

HighsOptionType

This defines the types of option values that control HiGHS:

• kBool: The option type is boolean
• kInt: The option type is integer
• kDouble: The option type is double
• kString: The option type is string

HighsInfoType

This defines the types of (scalar) information available after a call to run:

• kInt64: The information type is 64-bit integer
• kInt: The information type is integer
• kDouble: The information type is double

highs documentation built on April 4, 2025, 3:23 a.m.