The SOLVLG parameter can be used to control the amount of output the solver engines display while running. By default, LINGO does not display much solver log output. However, some technical users may be curious to see this information. Below is a selection of some log output from a small integer program:

Number of constraints:       2    le:       1, ge:       0, eq:       1, rn:       0 (ne:0)

Number of variables  :       9    lb:       1, ub:       0, fr:       0, bx:       8 (fx:0)

Number of nonzeroes  :      12    density:  0.0067(%)     , sb:       0

 

Abs. Ranges     :         Min.          Max.    Condition.

Matrix Coef. (A):      1.00000       7.00000       7.00000

Obj. Vector  (c):      1.00000      10.00000      10.00000

RHS Vector   (b):     15.00000      15.00000       1.00000

Lower Bounds (l):  1.0000e-100   1.0000e-100       1.00000

Upper Bounds (u):      1.00000       1.00000       1.00000

BadScale Measure: 0

 

Binary variables     :       8 (in 2 constraints)

Integer variables    :       0 (in 0 constraints)

 

Startpoint info (not feasible):

 Objvalue                         : 3.500000e+01  (startpoint)

 Infeasibility of solution        : 1.8e+01

 Integer infeasibility of solution: 0.0e+00

 

Feasible obj value found in MIP prerelax heu=0.000000

Setting the log level to higher integer values may result in a higher level of output. In general, a level of 1 is perhaps the most useful and meaningful.  Setting the log level to 0 disables solver logs, which is the default setting.