> I am using GLPK to create an LP file which I will later optimize using > CPLEX. > But while I am creating the LP file, the following error occurs. > ##### > glp_add_rows: nrs = 186919944; too many rows > error detected in file ..\src\glpapi01.c at line 251 > ##### > > > I checked the resepectiv .C file and found that GLPK has a row limit > of 100000000. Can this limit be changed ? > Could you help me with a way around this issue ? > For the back ground. This model is a energy systems model on the likes > of MARKAL in open source. This problem occurs when I am trying to > model the whole of Africa's energy system (more than 10 countries at a > time). My GNU Mathprog code is 470 line long and my data file is > 1000000 lines long. >
This limit is used to prevent possible integer overflow, because to access array elements glpk routines use indices of the 'int' type, which are 32-bit signed integers (on both 32- and 64-bit platforms). You may try to increase this limit, say, to 2*10^8, as well as other limits on the number of columns and non-zero constraint coefficients. However please note that the glpk itself is not intended to solve such huge models. _______________________________________________ Help-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-glpk
