On Thu, 2015-08-06 at 14:18 +0200, Michal Trněný wrote: > Here is a simple LP problem that GLPK didn't solve correctly: > maximize objective: 4*x1 + x2 + 2*x2 > given constraints: > var x1>=0; > var x2>=0; > var x3>=0; > c1: x1 <= 1; > c2: x2 <= 1; > c3: x3 <= 1; > c4: x1 + x2 + x3 = 2.5; > > Solver yielded answer: > x1=1, x2=1, x3=0.5, obj=7 > that is obviously wrong,
The answer is correct. Please check the last term in your objective. > because: > 4*1 + 1 + 2*0.5 != 7 but > 4*1 + 1 + 2*0.5 = 6 > and this solution (1,1,0.5) isn't optimal, because ... > there exist solution (1,0.5,1), which objective is 6.5 - bigger, than > objective of (1,1,0.5). > > You may imagine feasible region as unit cube with vertex (1,1,1) cuted > off. > > I'd like you to nottice me, when you fix this bug. > I want commented pseudocode of GLPK. > Do you have it? Thank you. > > -- > Michal Trněný > www.michaltrneny.cz _______________________________________________ Bug-glpk mailing list Bug-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/bug-glpk
