SolveParam (Java Optimization 1.3.0 API)

java.lang.Object
- edu.harvard.econcs.jopt.solver.SolveParam

All Implemented Interfaces:

Serializable
```
public class SolveParam
extends Object
implements Serializable
```
These parameters control how JOpt operates, and how the backend solver operates. You can control a number of parameters. Not all of these will be supported by your chosen backend solver, unfortunently. But we try to map these settings into relevant solver settings. See each setting to see if they are applicable to CPLEX, LPSOLVE, or ALLSOLVERS

Since:

Apr 19, 2005

Version:

$Revision: 1.2 $ on $Date: 2017/11/08 12:55:46 $

Author:

Benjamin Lubin; Last modified by $Author: blubin $

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static SolveParam`	`ABSOLUTE_INT_GAP` How close a double must be to an int to be considered an int [CPLEX]
`static SolveParam`	`ABSOLUTE_OBJ_GAP` Optimization stops when current solution within this parameter of LP relaxiation [CPLEX]
`static SolveParam`	`ABSOLUTE_VAR_BOUND_GAP` Degree to which variables may violate their bounds [CPLEX]
`static SolveParam`	`ACCEPT_SUBOPTIMAL` Flag whether the user wants to accept a suboptimal solution after timeout or have an Exception thrown.
`static SolveParam`	`BARRIER_DISPLAY` Amount of barrier progress information to be displayed [CPLEX]
`static SolveParam`	`CALC_DUALS` Calculate duals?
`static SolveParam`	`CALCULATE_CONFLICT_SET` Should we attempt to determine conflcit set?
`static SolveParam`	`CHECK_INIT_VALUE_FEASIBILITY` Check starting values for feasibility? [CPLEX]
`static SolveParam`	`CLOCK_TYPE` Measure timing using CPU=1, wall clock=2 [CPLEX]
`static SolveParam`	`CONSTRAINT_BACKOFF_LIMIT` Maximum amount to backoff and retry solving mip with looser constraint tolerance.
`static SolveParam`	`DISPLAY_OUTPUT` Display output?
`static SolveParam`	`LP_OPTIMIZATION_ALG` Which optimization algorithm to use.
`static SolveParam`	`MARKOWITZ_TOLERANCE` Set the Markov Tolerance [CPLEX] Influences pivot selection during basis factoring.
`static SolveParam`	`MAX_OBJ_THRESHOLD` For Maximization problems, stop when this value has been exceeded [CPLEX]
`static SolveParam`	`MAX_OBJ_VALUE` Max objective value for minimization problems (specified to assist cutting).
`static SolveParam`	`MIN_OBJ_THRESHOLD` For Minimization problems, stop when this value has been exceeded [CPLEX]
`static SolveParam`	`MIN_OBJ_VALUE` Min objective value for maximization problems (specified to assist cutting).
`static SolveParam`	`MIP_DISPLAY` Specify what to display when solving a MIP [CPLEX]
`static SolveParam`	`MIP_EMPHASIS` Optimality vs.
`static SolveParam`	`OBJ_TOLERANCE` Optimality Tolerance [CPLEX]
`static SolveParam`	`PARALLEL_MODE`
`static SolveParam`	`POPULATE_LIMIT` Sets the maximum number of mixed integer programming (MIP) solutions generated for the solution pool during each call to the populate procedure.
`static SolveParam`	`PROBLEM_FILE` Name of mipInstance file - set to empty string if you don't want to write one out [CPLEX]
`static SolveParam`	`RELATIVE_OBJ_GAP` Optimization stops when current solution within this percentage of LP relaxiation [CPLEX]
`static SolveParam`	`RELATIVE_POOL_SOLVE_TIME` How much of the time it took to solve the original problem should be spend on populating the solution pool.
`static SolveParam`	`SOLUTION_POOL_CAPACITY` Number of intermediate solutions to capture.
`static SolveParam`	`SOLUTION_POOL_INTENSITY` Controls the trade-off between the number of solutions generated for the solution pool and the amount of time or memory consumed.
`static SolveParam`	`SOLUTION_POOL_MODE` 0 (default) is none 1 is callback 2 is solution pool
`static SolveParam`	`SOLUTION_POOL_REPLACEMENT` Designates the strategy for replacing a solution in the solution pool when the solution pool has reached its capacity.
`static SolveParam`	`THREADS` Threads to use in solving a MIP [CPLEX]
`static SolveParam`	`TIME_LIMIT` Maximum time to run solver before returning current best in seconds [CPLEX]
`static SolveParam`	`WORK_DIR` Working directory for working files for the optimzer [CPLEX]
`static SolveParam`	`ZERO_MISSING_PROPOSED` If given a set of proposed starting values, should we set missing values to be zero [CPLEX]

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`equals(Object obj)`
`Class`	`getType()`
`String`	`getTypeDescription()`
`int`	`hashCode()`
`boolean`	`isBoolean()`
`boolean`	`isDouble()`
`boolean`	`isInteger()`
`boolean`	`isInternal()`
`boolean`	`isString()`
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - CLOCK_TYPE
```
public static final SolveParam CLOCK_TYPE
```
    Measure timing using CPU=1, wall clock=2 [CPLEX]
  - TIME_LIMIT
```
public static final SolveParam TIME_LIMIT
```
    Maximum time to run solver before returning current best in seconds [CPLEX]
  - BARRIER_DISPLAY
```
public static final SolveParam BARRIER_DISPLAY
```
    Amount of barrier progress information to be displayed [CPLEX]
  - MIN_OBJ_VALUE
```
public static final SolveParam MIN_OBJ_VALUE
```
    Min objective value for maximization problems (specified to assist cutting). Set this too high --> No Feasible Solution [CPLEX]
  - MAX_OBJ_VALUE
```
public static final SolveParam MAX_OBJ_VALUE
```
    Max objective value for minimization problems (specified to assist cutting). Set this too low --> No Feasible Solution [CPLEX]
  - OBJ_TOLERANCE
```
public static final SolveParam OBJ_TOLERANCE
```
    Optimality Tolerance [CPLEX]
  - ABSOLUTE_OBJ_GAP
```
public static final SolveParam ABSOLUTE_OBJ_GAP
```
    Optimization stops when current solution within this parameter of LP relaxiation [CPLEX]
  - RELATIVE_OBJ_GAP
```
public static final SolveParam RELATIVE_OBJ_GAP
```
    Optimization stops when current solution within this percentage of LP relaxiation [CPLEX]
  - ABSOLUTE_INT_GAP
```
public static final SolveParam ABSOLUTE_INT_GAP
```
    How close a double must be to an int to be considered an int [CPLEX]
  - ABSOLUTE_VAR_BOUND_GAP
```
public static final SolveParam ABSOLUTE_VAR_BOUND_GAP
```
    Degree to which variables may violate their bounds [CPLEX]
  - LP_OPTIMIZATION_ALG
```
public static final SolveParam LP_OPTIMIZATION_ALG
```
    Which optimization algorithm to use. [CPLEX]
  - MIP_DISPLAY
```
public static final SolveParam MIP_DISPLAY
```
    Specify what to display when solving a MIP [CPLEX]
    
    From the Cplex 8.1 Documentation (see that documentation for better context):
    
    0 No display
    1 Display integer feasible solutions
    2 Display nodes under CPX_PARAM_MIPInteger.classERVAL
    3 Same as 2 with information on node cuts
    4 Same as 3 with LP subproblem information at root
    5 Same as 4 with LP subproblem information at nodes
    Default: 2
    Description: MIP node log display information.
    Determines what CPLEX reports to the screen during mixed integer optimization. The amount of information displayed increases with increasing values of this parameter. A setting of 0 causes no node log to be displayed until the optimal solution is found. A setting of 1 displays an entry for each integer feasible solution found. Each entry contains the objective function value, the node count, the number of unexplored nodes in the tree, and the current optimality gap. A setting of 2 also generates an entry for every nth node (where n is the setting of the MIP Integer.classERVAL parameter). A setting of 3 additionally generates an entry for every nth node giving the number of cuts added to the problem for the previous Integer.classERVAL nodes. A setting of 4 additionally generates entries for the LP root relaxation according to the 'SET SIMPLEX DISPLAY' setting. A setting of 5 additionally generates entries for the LP subproblems, also according to the 'SET SIMPLEX DISPLAY' setting.
  - MIP_EMPHASIS
```
public static final SolveParam MIP_EMPHASIS
```
    Optimality vs. Feasibility heuristic for MIP solving. 0=balanced, 1=feasibility, 2=optimality, 3=moving best bound. [CPLEX]
  - CHECK_INIT_VALUE_FEASIBILITY
```
public static final SolveParam CHECK_INIT_VALUE_FEASIBILITY
```
    Check starting values for feasibility? [CPLEX]
  - MIN_OBJ_THRESHOLD
```
public static final SolveParam MIN_OBJ_THRESHOLD
```
    For Minimization problems, stop when this value has been exceeded [CPLEX]
  - MAX_OBJ_THRESHOLD
```
public static final SolveParam MAX_OBJ_THRESHOLD
```
    For Maximization problems, stop when this value has been exceeded [CPLEX]
  - WORK_DIR
```
public static final SolveParam WORK_DIR
```
    Working directory for working files for the optimzer [CPLEX]
  - THREADS
```
public static final SolveParam THREADS
```
    Threads to use in solving a MIP [CPLEX]
  - PARALLEL_MODE
```
public static final SolveParam PARALLEL_MODE
```
  - MARKOWITZ_TOLERANCE
```
public static final SolveParam MARKOWITZ_TOLERANCE
```
    Set the Markov Tolerance [CPLEX]
    Influences pivot selection during basis factoring. Increasing the Markowitz threshold may improve the numerical properties of the solution.
    Value: Any number from 0.0001 to 0.99999; default: 0.01.
  - SOLUTION_POOL_INTENSITY
```
public static final SolveParam SOLUTION_POOL_INTENSITY
```
    Controls the trade-off between the number of solutions generated for the solution pool and the amount of time or memory consumed. This parameter applies both to MIP optimization and to the populate procedure. Values from 1 (one) to 4 invoke increasing effort to find larger numbers of solutions. Higher values are more expensive in terms of time and memory but are likely to yield more solutions.
  - SOLUTION_POOL_CAPACITY
```
public static final SolveParam SOLUTION_POOL_CAPACITY
```
    Number of intermediate solutions to capture. 0 turns of populate. Defaults to 0.
  - POPULATE_LIMIT
```
public static final SolveParam POPULATE_LIMIT
```
    Sets the maximum number of mixed integer programming (MIP) solutions generated for the solution pool during each call to the populate procedure. Populate stops when it has generated PopulateLim solutions. A solution is counted if it is valid for all filters, consistent with the relative and absolute pool gap parameters, and has not been rejected by the incumbent callback (if any exists), whether or not it improves the objective of the model. In parallel, populate may not respect this parameter exactly due to disparities between threads. That is, it may happen that populate stops when it has generated a number of solutions slightly more than or slightly less than this limit because of differences in synchronization between threads.
  - SOLUTION_POOL_REPLACEMENT
```
public static final SolveParam SOLUTION_POOL_REPLACEMENT
```
    Designates the strategy for replacing a solution in the solution pool when the solution pool has reached its capacity. The value 0 (CPX_SOLNPOOL_FIFO ) replaces solutions according to a first-in, first-out policy. The value 1 (CPX_SOLNPOOL_OBJ ) keeps the solutions with the best objective values. The value 2 (CPX_SOLNPOOL_DIV ) replaces solutions in order to build a set of diverse solutions. If the solutions you obtain are too similar to each other, try setting SolnPoolReplace to 2. The replacement strategy applies only to the subset of solutions created in the current call of MIP optimization or populate. Solutions already in the pool are not affected by the replacement strategy. They will not be replaced, even if they satisfy the criterion of the replacement strategy.
  - PROBLEM_FILE
```
public static final SolveParam PROBLEM_FILE
```
    Name of mipInstance file - set to empty string if you don't want to write one out [CPLEX]
  - ZERO_MISSING_PROPOSED
```
public static final SolveParam ZERO_MISSING_PROPOSED
```
    If given a set of proposed starting values, should we set missing values to be zero [CPLEX]
  - CONSTRAINT_BACKOFF_LIMIT
```
public static final SolveParam CONSTRAINT_BACKOFF_LIMIT
```
    Maximum amount to backoff and retry solving mip with looser constraint tolerance. CPlex max is .1, .1 is default. typically either .1 or 0
  - CALCULATE_CONFLICT_SET
```
public static final SolveParam CALCULATE_CONFLICT_SET
```
    Should we attempt to determine conflcit set?
  - DISPLAY_OUTPUT
```
public static final SolveParam DISPLAY_OUTPUT
```
    Display output?
  - CALC_DUALS
```
public static final SolveParam CALC_DUALS
```
    Calculate duals?
  - SOLUTION_POOL_MODE
```
public static final SolveParam SOLUTION_POOL_MODE
```
    0 (default) is none 1 is callback 2 is solution pool
  - RELATIVE_POOL_SOLVE_TIME
```
public static final SolveParam RELATIVE_POOL_SOLVE_TIME
```
    How much of the time it took to solve the original problem should be spend on populating the solution pool. If missing or negative than populate is not limited
  - ACCEPT_SUBOPTIMAL
```
public static final SolveParam ACCEPT_SUBOPTIMAL
```
    Flag whether the user wants to accept a suboptimal solution after timeout or have an Exception thrown.
- Method Detail
  - getType
```
public Class getType()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - isInteger
```
public boolean isInteger()
```
  - isDouble
```
public boolean isDouble()
```
  - isBoolean
```
public boolean isBoolean()
```
  - isString
```
public boolean isString()
```
  - isInternal
```
public boolean isInternal()
```
  - getTypeDescription
```
public String getTypeDescription()
```
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object

Class SolveParam

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

CLOCK_TYPE

TIME_LIMIT

BARRIER_DISPLAY

MIN_OBJ_VALUE

MAX_OBJ_VALUE

OBJ_TOLERANCE

ABSOLUTE_OBJ_GAP

RELATIVE_OBJ_GAP

ABSOLUTE_INT_GAP

ABSOLUTE_VAR_BOUND_GAP

LP_OPTIMIZATION_ALG

MIP_DISPLAY

MIP_EMPHASIS

CHECK_INIT_VALUE_FEASIBILITY

MIN_OBJ_THRESHOLD

MAX_OBJ_THRESHOLD

WORK_DIR

THREADS

PARALLEL_MODE

MARKOWITZ_TOLERANCE

SOLUTION_POOL_INTENSITY

SOLUTION_POOL_CAPACITY

POPULATE_LIMIT

SOLUTION_POOL_REPLACEMENT

PROBLEM_FILE

ZERO_MISSING_PROPOSED

CONSTRAINT_BACKOFF_LIMIT

CALCULATE_CONFLICT_SET

DISPLAY_OUTPUT

CALC_DUALS

SOLUTION_POOL_MODE

RELATIVE_POOL_SOLVE_TIME

ACCEPT_SUBOPTIMAL

Method Detail

getType

toString

isInteger

isDouble

isBoolean

isString

isInternal

getTypeDescription

equals

hashCode