Re: [Bug-glpk] Problem in the MIP problem

[Cedric[FR]]

Andrew Makhorin wrote:
> 
>>> I don't use functions glp_read_lp or glp_read_cpxlp.
> 
>>> And, I use GLP_FX (not GLP_DB) to fix bounds for the first variable.
> 
>>> So, I don't understand.
> 
>>> And, when I use lpx_write_cpxlp, I obtain this result.
> 
>>> The problem is that variables aren't integer and the first variable
>>> bound
>>> is
>>> displayed as 1 <= Yi0_copy <= 1
> 
>> It is strange, because glp_write_lp (lpx_write_cpxlp) writes fixed
>> variables as <varname> = <fixed value>; it writes both bounds only if
>> the variable is double-bounded.
> 
> 
>> I test variable sense after this command
>> glp_set_col_bnds(glpkProbPtr,id+1,GLP_FX,dlb[id],dub[id]) and this
>> test show that variables are double-bounded instead of fixed
> 
> Hmm... There is something wrong. Please print the type and bounds
> of the variable reported by glp_get_col_type, glp_get_col_lb, and
> glp_get_col_ub immediately after glp_set_col_bnds(... GLP_FX ...).
> The type reported must be GLP_FX = 5. If not, please check your code.
> 
> Hi,
> 
> I check my code and I resolve my problem. But, an other problem appear.
> 
> When I fix a variable at one, and after, I define the type as binary, then
> the lower bound is 0 instead of 1.
> 
> I resolve this problem in declaring variables as integer. But, why
> glp_set_col_kind redefine the lower bound
> 
> Thanks
> 
> Cédric
> 
> _______________________________________________
> Bug-glpk mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/bug-glpk
> 
> 

-- 
View this message in context: 
http://www.nabble.com/Problem-in-the-MIP-problem-tp20030554p20188642.html
Sent from the Gnu - GLPK - Bugs mailing list archive at Nabble.com.