Other Changes to LOG 2.0



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There have been numerous improvements made to LOG since the last version. Some of these changes have already been described in this webpage. Other changes made to LOG are described below.



When a problem in LOG is solved, AMPL model, data and run files are created. AMPL then calls a solver, which then solves the linear program. The AMPL code used in the previous version of LOG was too memory intensive. Large problems took look amounts of time to solve. The trouble with the code was that every variable was being initialised, when in actual fact only some of the variables were needed. The AMPL code now only defines variables over ranges that are valid. This has the desirable effects of making the code more efficient and speeding up the running time of the program.


Scroll Bars

Some users of the previous versions of LOG may have been aware that there were problems with the scroll bars. They had a tendency to flash when in focus. There was a maximum value that the scroll bar could reach, this maximum value would come into play after only 10 - 15 constraints were added. The new scroll bars included in LOG 2.0 are vastly better. They do not flash, there is also no maximum value imposed on the scroll bar. The number of constraints that can be added is now limited by the maximum size of the frame. This should not hinder small problems as over 100 constraints can still be added to the model.