GAMS — The Solver Manuals - Available Software

COIN-OR 91
ma27 skip inertia check: Always pretend inertia is correct.
Setting this option to ”yes” essentially disables inertia check. This option makes the algorithm non-robust and
easily fail, but it might give some insight into the necessity of inertia control. The default value for this string
option is ”no”.
Possible values:
• no: check inertia
• yes: skip inertia check
MA28 Linear Solver
ma28 pivtol: Pivot tolerance for linear solver MA28.
This is used when MA28 tries to find the dependent constraints. The valid range for this real option is 0 <
ma28 pivtol ≤ 1 and its default value is 0.01.
MA57 Linear Solver
ma57 pivtol: Pivot tolerance for the linear solver MA57.
A smaller number pivots for sparsity, a larger number pivots for stability. This option is only available if Ipopt
has been compiled with MA57. The valid range for this real option is 0 < ma57 pivtol < 1 and its default value
is 1 · 10 −08 .
ma57 pivtolmax: Maximum pivot tolerance for the linear solver MA57.
Ipopt may increase pivtol as high as ma57 pivtolmax to get a more accurate solution to the linear system.
This option is only available if Ipopt has been compiled with MA57. The valid range for this real option is
0 < ma57 pivtolmax < 1 and its default value is 0.0001.
ma57 pre alloc: Safety factor for work space memory allocation for the linear solver MA57.
If 1 is chosen, the suggested amount of work space is used. However, choosing a larger number might avoid
reallocation if the suggest values do not suffice. This option is only available if Ipopt has been compiled with
MA57. The valid range for this real option is 1 ≤ ma57 pre alloc < +inf and its default value is 3.
Mumps Linear Solver
mumps dep tol: Pivot threshold for detection of linearly dependent constraints in MUMPS.
When MUMPS is used to determine linearly dependent constraints, this is determines the threshold for a pivot to
be considered zero. This is CNTL(3) in MUMPS. The valid range for this real option is −inf < mumps dep tol <
+inf and its default value is −1.
mumps mem percent: Percentage increase in the estimated working space for MUMPS.
In MUMPS when significant extra fill-in is caused by numerical pivoting, larger values of mumps mem percent may
help use the workspace more efficiently. The valid range for this integer option is 0 ≤ mumps mem percent < +inf
and its default value is 1000.
mumps permuting scaling: Controls permuting and scaling in MUMPS
This is ICTL(6) in MUMPS. The valid range for this integer option is 0 ≤ mumps permuting scaling ≤ 7 and
its default value is 7.
mumps pivot order: Controls pivot order in MUMPS
This is ICTL(7) in MUMPS. The valid range for this integer option is 0 ≤ mumps pivot order ≤ 7 and its default
value is 7.