[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
## Re: [Help-glpk] Initial starting point of simplex algorithm

**From**: |
Andrew Makhorin |

**Subject**: |
Re: [Help-glpk] Initial starting point of simplex algorithm |

**Date**: |
Thu, 24 Jan 2013 17:40:34 +0400 |

>* PS: here is a small log of both problems*
>* *
>* GLPK Simplex Optimizer, v4.47*
>* 191255 rows, 68860 columns, 450946 non-zeros*
>* 0: obj = 0.000000000e+000 infeas = 5.436e+009 (28783)*
>* ...*
>* 17761: obj = -8.927238865e+008 infeas = 2.030e+007 (14520)*
>* PROBLEM HAS NO FEASIBLE SOLUTION*
>* *
>* Elasticity*
>* Addtional constraints 220038 for 191255 rows*
>* Current column size is 68860*
>* Additional Constraints 220038*
>* Current column size after resize is 288898*
>* GLPK Simplex Optimizer, v4.47*
>* 191255 rows, 288898 columns, 642201 non-zeros*
>* 0: obj = 0.000000000e+000 infeas = 5.436e+009 (28783)*
>* ...*
>* * 1552: obj = 0.000000000e+000 infeas = 1.490e-008 (28782)*
>* OPTIMAL SOLUTION FOUND*
>* Sinf is 0*
BTW, in the second case the objective (Sinf, I guess) is zero on all
iterations. Probably you forgot to assign objective coefficients to
elastic variables.