Hello, I'm a PhD Student and I'm using glpk to solve quite large linear programming problems.
I want to notice that I'm french and I apologize if my english is bad, I'll try to explain clearly my problem. At first I want to thank you and all the team ; I'm using glpk since release 4.13, and I'm very satisfied with this package which helps me a lot in my work ! Now I'm using glpk 4.43, I've read the doc and I don't find how to make a "warm start" : I want to solve a first time my problem, and then I would like to modify only one item ( an objective coefficient or a bound value ), and solving again the problem in "warm start", I mean by using the basis previously found on first solving without solving problem again or factorisation again ( just in order to save time, my problems are very long to solve and I will have to make many iteration this way ). I've found the routine lpx_warms_up which looks like but it's not exactly what I need. I've not found in the documentation the routines I need, is it possible to do that with glpk ? If it is, can you please highlight me with the routines I should use ? Thanks and again thank you for your job with glpk ! Le 26 mars 2010 à 10:03, Richard Simonnet a écrit : > > It works fine again with glpk 4.43 strange .... > > thanks > > Le 18 mars 2010 а 12:15, Andrew Makhorin a йcrit : > >>> At first, I want to explain that I'm a french student and I >>> apologize if my english is bad, and I'll try to explain clearly my >>> problem. >> >>> As part of my PhD, I'm using the glpk routines to solve linear >>> programming problems, with programs in language C running under Linux >>> terminal. >> >>> I was using glpk 4.25 and I've just updated to glpk 4.35 and with >>> this release, the function "glp_term_out" with the option "GLP_OFF" >>> seems to not work. >> >>> While running program with this option, I get no error message but >>> the program seems to be in "pause" on this step; though I was using >>> this option with glpk 4.25 without problem. >> >>> Is there a known problem with this function ? >> >> Hmm... Glp_term_out must work. If you disable the terminal output and >> then call glp_simplex, it may happen that the simplex solver is stalling >> due to degeneracy, however, you cannot see that. Try to enable the >> terminal output to make sure that glp_simplex is not stalling. >> >> (Please note that the most recent version of glpk is 4.43.) >> >> > _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
