The SET command allows you to override LINGO's default tolerances and settings. All user configurable options in LINGO are available through the SET command. The syntax for the SET command is:

SET parameter_name | parameter_index [parameter_value]

where,

parameter_nameis the name of the parameter to set,
parameter_indexis the index of the parameter to set, and
parameter_valueis the new value for the parameter that, if omitted, will cause LINGO to display the current value for the specified parameter.

Use the FREEZE command to save any tolerances modified with the SET command to the configuration file, so they will be automatically restored the next time LINGO starts. You may also enter SET DEFAULT to return all parameters to their default values.

Some examples of the SET command follow:

Example 1:

SET MXMEMB 128

 

FREEZE

  sets the generator memory limit to 128MB and saves parameter settings to

  the configuration file,

Example 2:        SET 5 1.E-7

  sets the relative integrality tolerance (RELINT) to 1.e-7,

Example 3:        SET DEFAULT

  restores all parameters to their default values, and

Example 4:        HELP SET

  causes LINGO to display all parameter settings.

The parameters accessible through the SET command are:

 

Index

Parameter

Name

 

Default

 

Description

1

ILFTOL

0.3e-5

Initial linear feasibility tolerance

2

FLFTOL

0.1e-6

Final linear feasibility tolerance

3

INFTOL

0.1e-2

Initial nonlinear feasibility tolerance

4

FNFTOL

0.1e-5

Final nonlinear feasibility tolerance

5

RELINT

0.8e-5

Relative integrality tolerance

6

NOPTOL

0.1e-6

NLP optimality tolerance

7

ITRSLW

5

Iteration limit for slow progress

8

DERCMP

0

Derivatives (0:LINGO chooses, 1:backward analytical, 2:forward analytical, 3:central differences, 4:forward differences)

9

ITRLIM

0

Iteration limit (0:no limit)

10

TIMLIM

0

Solver time limit in seconds (0:no limit)

11

OBJCTS

1

Objective cuts (1:yes, 0:no)

12

MXMEMB

32

Memory limit in megabytes for LINGO’s model generator (N/A on some machines)

13

CUTAPP

2

Cuts application (0:root, 1:all, 2:solver chooses)

14

ABSINT

.000001

Absolute integrality tolerance

15

HEURIS

3

IP heuristics (0:none, 100:advanced)

16

HURDLE

0

Use an IP hurdle value (1:yes, 0:no)

17

IPTOLA

0

IP absolute optimality tolerance

18

IPTOLR

.1e-4

IP relative optimality tolerance

19

TIM2RL

100

Seconds before switching to IP relative optimality tolerance

20

NODESL

0

0:LINGO decides, 1:depth first, 2:worst bound, 3:best bound

21

LENPAG

0

Terminal page length limit (0:none)

22

LINLEN

85

Terminal page width (0:none)

23

TERSEO

0

Output level (0:verbose, 1:terse, 2:errors only, 3:no output)

24

STAWIN

1

Post status window (1:yes, 0:no)

25

SPLASH

1

Display splash screen  (1:yes, 0:no)

26

OROUTE

0

Route output to command window (1:yes, 0:no)

27

WNLINE

800

Max command window lines

28

WNTRIM

400

Min command window lines

29

STABAR

1

Display status bar (1:yes, 0:no)

30

FILFMT

1

File format (0:lng, 1:lg4,  2:ltx)

31

TOOLBR

1

Display toolbar (1:yes, 0:no)

32

CHKDUP

0

Check for duplicate model names in data (1:yes, 0:no)

33

ECHOIN

0

Echo command input to terminal (1:yes, 0:no)

34

ERRDLG

1

Route error messages to a dialog box (1:yes, 0:no)

35

USEPNM

0

Allow for unrestricted use of primitive set names (1:yes, 0:no)

36

NSTEEP

0

Use steepest edge variable selection in nonlinear solver (1:yes, 0:no)

37

NCRASH

0

Run crash procedure 1 to get an initial starting point in nonlinear models (1:yes, 0:no). See parameter 91, LCRASH, below for alternative procedure.

38

NSLPDR

1

Compute search directions in nonlinear solver using successive linear programming (1:yes, 0:no)

39

SELCON

0

Use selective constraint evaluation in nonlinear solver (1:yes, 0:no)

40

PRBLVL

0

Specify probing level on MILPs (0:LINGO chooses,  1:none, 7:high)

41

SOLVEL

0

Specify linear solver (0:LINGO chooses, 1:primal, 2:dual, 3:barrier)

42

REDUCE

2

Perform model reduction (2:LINGO chooses, 1:yes, 0:no)

43

SCALEM

1

Scale the model (1:yes, 0:no)

44

PRIMPR

0

Select primal pricing method (0:LINGO chooses, 1:partial, 2:devex)

45

DUALPR

0

Select dual pricing method (0:LINGO chooses, 1:Dantzig, 2:steepest edge)

46

DUALCO

1

Specify dual computations (0:none, 1:prices only, 2:prices and ranges, 3:prices only on optimizable rows)

47

RCMPSN

0

Use RC format names for MPS I/O (1:yes, 0:no)

48

MREGEN

2

Select model regeneration (0:only on modifications to model, 1:same as 0 plus whenever model has external references, 2:always)

49

BRANDR

0

Select branch direction (0:both, 1:up, 2:down)

50

BRANPR

0

Select branch priority (0:LINGO decides, 1:binary)

51

CUTOFF

.1e-8

Cutoff solution values smaller than this

52

STRONG

10

Specify strong branch level

53

REOPTB

0

IP warm start LP (0:LINGO, 1:primal, 2:dual, 3:barrier)

54

REOPTX

0

IP cold start LP (0:LINGO, 1:primal, 2:dual, 3:barrier)

55

MAXCTP

100

Max top cuts passes

56

RCTLIM

.75

Relative cuts limit

57

GUBCTS

1

GUB cuts (1:yes, 0:no)

58

FLWCTS

1

Flow cuts (1:yes, 0:no)

59

LFTCTS

1

Lift cuts (1:yes, 0:no)

60

PLOCTS

1

Plant location cuts (1:yes, 0:no)

61

DISCTS

1

Disaggregation cuts (1:yes, 0:no)

62

KNPCTS

1

Knapsack cover cuts (1:yes, 0:no)

63

LATCTS

1

Lattice cuts (1:yes, 0:no)

64

GOMCTS

1

Gomory cuts (1:yes, 0:no)

65

COFCTS

1

Coefficient reduction cuts (1:yes, 0:no)

66

GCDCTS

1

Greatest common divisor cuts (1:yes, 0:no)

67

SCLRLM

1,000

Syntax coloring line limit

68

SCLRDL

0

Syntax coloring delay in seconds

69

PRNCLR

1

Matching parenthesis coloring (1:yes, 0:no)

70

MULTIS

0

NLP multistart attempts (0:LINGO, n:number of attempts)

71

USEQPR

1

Use quadratic recognition (1:yes, 0:no)

72

GLOBAL

0

Use global solver on NLPs (1:yes, 0:no)

73

LNRISE

0

Linearization (0:LINGO, 1:none, 2:low, 3:high)

74

LNBIGM

100,000

Linearization BigM coefficient

75

LNDLTA

.1e-5

Linearization Delta coefficient

76

BASCTS

1

Basis cuts (1:yes, 0:no)

77

MAXCTR

2

Max tree cuts passes

78

HUMNTM

0

Minimum heuristic time limit (seconds)

79

DECOMP

0

Matrix decomposition (1:yes, 0:no)

80

GLBOPT

.1e-4

Global solver optimality tolerance

81

GLBDLT

.1e-6

Global solver delta tolerance

82

GLBVBD

.1e+11

Global solver variable bound limit

83

GLBUBD

2

Global solver bound use (0:no, 1:all, 2:some)

84

GLBBRN

5

Global solver branch selection (see below)

85

GLBBXS

1

Global solver box selection (0:depth first, 1:worst bound)

86

GLBREF

3

Global solver reformulation level (0:none, 3:high)

87

SUBOUT

2

Fixed variable reduction (0:none, 1:max, 2:not when using global or multistart solvers, 3:linear variables only)

88

NLPVER

N/A

No longer supported

89

DBGCLD

0

Debugging cold start solver (0:LINGO, 1:primal, 2:dual, 3:barrier)

90

DBGWRM

0

Debug warm start solver (0:LINGO, 1:primal, 2:dual, 3:barrier)

91

LCRASH

0

Run crash procedure 2 to get an initial starting point in nonlinear models (1:yes, 0:no). See parameter 37, NCRASH, above for alternative procedure.

92

BCROSS

1

Perform a basis crossover on LPs when using barrier solver (0:no, 1:yes)

93

LOWMEM

0

Opt for less memory usage (0:no, 1:yes)

94

FILOUT

0

Fill out workbook output ranges (0:no, 1:yes)

95

DBGLVL

15

Debugger output level (1:low, 15:high)

96

UNARYM

1

Unary minus priority (0:low, 1:high)

97

LINEAR

0

Assume model is linear to reduce memory consumption(0:no, 1:yes)

98

LOPTOL

.1e-6

Linear optimality tolerance

99

SECORD

0

Use second order derivatives for NLPs (0:no, 1:yes)

100

NONNEG

1

Variables default to being non-negative (0:no, 1:yes)

101

BIGMVL

1.e8

BigM coefficient threshold value

102

KILLSC

0

Kill scripts on interrupts (0:no, 1:yes)

103

TATSLV

0

@SOLVE time limit in seconds

104

KBESTS

1

Number of K-Best MIP solutions to generate

105

LCORES

1

Number of concurrent LP solvers to run

106

LCORE1

1

LP Solver in Core 1 (1:prm1,2:dual,3:barrier,4:prim2)

107

LCORE2

2

LP Solver in Core 2

108

LCORE3

3

LP Solver in Core 3

109

LCORE4

4

LP Solver in Core 4

110

SCALEW

1.e12

Scaling warning threshold

111

REFRAQ

0

Basis refactor frequency (0:LINGO chooses, iteration count)

112

SPSMSZ

2

Default SP sample size per stage

113

SPSCON

1

Apply SP sampling to continuous random variables only (0:no, 1:yes)

114

SPSEED

1,031

SP sampling random number seed

115

SPMTHD

0

SP solution method (0:LINGO chooses, 1:deterministic equivalent, 2:nested Benders, 3:augmented Lagrangian)

116

SPXVAL

1

Calculate all SP expected value statistics (0:no, 1:yes)

117

SPMAXS

40,000

Max scenarios allowed in an SP before auto sampling takes effect

118

PRECIS

7

Precision in digits for standard solution reports

119

LOOPOP

0

Perform loop optimization during model compiles (0:no, 1:yes)

120

HEUCUT

0

Heuristics cutoff criterion (0:LINGO chooses, 1:time, 2:iterations)

121

NUMBIN

0

Number of bins in histogram charts (0:LINGO chooses, >0: number of bins)

122

SPBIGM

1.E8

Stochastic solver Big M coefficient

123

NSLPSV

0

Use SLP solver for nonlinear models (0:no, 1:yes)

124

FORCEB

0

Enforce variable bounds in calc and data sections (0:no, 1:yes)

125

NTHRDS

1

Max number of executions threads (0:use all cores, 1:single-threaded, N>1:use up to N threads

126

MTMODE

-1

Multithreading mode(

-1:LINGO chooses,0:off in solver, 1:prefer parallel, 2:parallel exclusively, 3:prefer concurrent, 4:concurrent exclusively)

127

BNPBLK

2

Branch-and-price (BNP) blocks (0:use row names, 1:user specified, 2:off, >2:max number of blocks)

128

BNPHEU

1

BNP block-finding heuristic (1:GP1, 2:GP2)

129

REPROD

1

Favor reproducibility (0:no, 1:yes)