Some of the more common messages and codes passed by CLP are listed in the tables below. This is list is not meant to exhaustive. The notation is as for printf from "C": %s is a string %d is an integer %g or %f is a floating point value Code Area Text and notes 1 MPSREAD At line %d %s This just prints out NAME line, ROW line, etc 2 MPSREAD Problem %s has %d rows, %d columns and %d elements This gives statistics after reading an MPS file 8 MPSREAD %s read with %d errors This gives error statistics for file 505 PRESOLVE Presolved poblem not optimal, resolve after postsolve This could be because it was not feasible or because of maximum iterations. If this message occurs then consider using primal clean up 506 PRESOLVE Presolve %d (%d) rows, %d (%d) columns and %d (%d) elements The first number is the number after presolve and the number in parentheses is amount of reduction 510 PRESOLVE Presolve is modifying %d integer bounds and re-presolving If presolve determines at the end that an integer variable have its bounds changed then it will repeat the entrire presolve 511 PRESOLVE After Postsolve, objective %g, infeasibilities - dual %g (%d), primal %g (%d) This gives the state after postsolve - this gives the objective value and the sum of dual and primal infeasibilities with the number of infeasibilities in parentheses. Hopefully these should be zero 512 PRESOLVE Presolved model was optimal, full model needs cleaning up If the numbers in previous message (511) were large then maybe we need to know, if small then that's life Code Area Text and notes 0 SIMPLEX Optimal - objective value %g The only message you want to see 1 SIMPLEX Primal infeasible - objective value %g You may need to look at previous messages or use methods. Such as sumPrimalInfeasibilities() to find cause 2 SIMPLEX Dual infeasible - objective value %g You may need to look at previous messages or use methods. Such as sumDualInfeasibilities() to find cause 3 SIMPLEX Stopped - objective value %g The algorithm stopped as requested by the user. 4 SIMPLEX Stopped due to errors - objective value %g Switch on log level 2 to see information on size of elements etc. If they look reasonable then maybe we need to know. 5 SIMPLEX %d Obj %g Primal inf %g (%d) Dual inf %g (%d) At each re-factorization this gives the number of iterations and the value of the objective function. If there are primal infeasibilities then the sum and number are given and similarly for dual infeasibilities. (This is a simplified form of message.) 14 SIMPLEX Perturbing problem by %g % of %g There is more to this message but if the user sees this then s/he has chosen to perturb the problem or the algorithm has decided to do so. If the numbers look too large the user may wish to think again. 19 SIMPLEX %d variables/rows fixed as scaled bounds too close If this occurs look carefully at your input data 24 SIMPLEX Matrix will be packed to eliminate small elements If this occurs the user should look carefully at data. 26 SIMPLEX Matrix will be packed to eliminate %d duplicate elements If this occurs the user should look carefully at data. 28 SIMPLEX Crash put %d variables in basis, %d dual infeasibilities 29 SIMPLEX End of values pass after %d iterations ??? If primal(1) or dual(1) the a sweep through model is made and this signals end of pass. Code Area Text and notes 3001 MPSREAD Illegal value for %s of %g String will be "infinity" if setInfinity passed bad value, or "default integer bound" if setDefaultBound passed bad value. 3002 MPSREAD Bad image at line %d < %s > This gives line number and the offending line 3003 MPSREAD Duplicate objective at line %d < %s > An objective row appears twice in one column 3004 MPSREAD Duplicate row %s at line %d %s The named row appears twice in one column. 3005 MPSREAD No match for row %s at line %d < %s > The named row did not appear in ROWS section. 3006 MPSREAD No match for column at line %d < %s > The named column (in BOUNDS section) did not appear in COLUMNS section. 6001 MPSREAD Unable to open mps input file %s 6002 MPSREAD Unknown image %s at line %d of file %s The Mps reader could not make sense of the image file specified. 6003 MPSREAD Consider the possibility of a compressed file which zlib is unable to read. Some .gz files can not be read by zlib. Using gunzip and then gzip normally cures problem. 6004 MPSREAD EOF on file %s The Mps reader did not find expected section marker. 6005 MPSREAD Returning as too many errors The reader has put out 100 messages and is giving up. 507 PRESOLVE Presolve determined that the problem is infeasible with tolerance of %g If you want you can try with a larger tolerance 508 PRESOLVE Presolve thinks problem is unbounded Perhaps the user should maximize if initially minimizing or vice versa. 509 PRESOLVE Presolve thinks problem is infeasible AND unbounded??? If you get this message we want to know Code Area Text and notes 3002 SIMPLEX Not solving empty problem - %d rows, %d columns and %d elements Test problem size before solving. 6002 SIMPLEX %d bad bound pairs or bad objectives were found Either the value in the objective was too large or a lower bound was greater than an upper bound. 6003 SIMPLEX Matrix has %d large values, first at column %d, row %d is %g Some of the values in matrix are ridiculous. 6004 SIMPLEX Can't get out of loop ... There are also messages available at log level 2 (the most likely useful relate to scaling), and will be addressed in a future version of this User Guide.