Forum Discussion
Why Mosel result is not as optimal as Gams result?
Hi, I use both Gams and FICO Mosel to solve the same model, but the result from Mosel is not as optimal as the result from Gams. What might cause this difference? 1. It's a MIP problem 2. Set the ...
Hi JW,
In Mosel you should consider to change the following four parameters: MIPABSSTOP, MIPRELSTOP, MIPADDCUTOFF, MIPRELCUTOFF. Please have a look at the Optimizer documentation to get more information about those parameters. I usually choose the parameters as follows:
setparam('XPRS_MIPABSSTOP', MY_MIPABSSTOP) setparam('XPRS_MIPRELSTOP', MY_MIPRELSTOP) setparam('XPRS_MIPADDCUTOFF', MY_MIPABSSTOP) setparam('XPRS_MIPRELCUTOFF', MY_MIPRELSTOP)If you want to print or compare very small numbers, then you have to modify the Mosel 'zerotol' parameter. Please have a look at the Mosel documentation for more details about that Mosel parameter. Simply set the zerotol to zero if you work with numbers smaller than 1e-13. Note that the zerotol only affects number comparisons and number to text conversions. The actual numbers stored in memory are not affected by the zerotol, in particular Mosel does not round the numbers. Only the number to text conversion rounds the values.
setparam('zerotol', 0)Regards,
Johannes
