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

[Andrew Makhorin]

> 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.

Could you check your code more carefully?

> It is surprising because, when I use get_get_col_kind, variables are
> integers.

All variables are integer as indicated by 'generals'.

> PS: I use GLPK 4.28. I can try to use the last version.

> \* Problem: spConf_ *\

> Minimize
>  Objectif: - 11.6666666666667 Yi0_copy - 11.6666666666667 Yi1_copy
>  - 5 Yi2_copy - 5 Yi3_copy - 2.7 Yi4_copy - 4.6 Yi5_copy - 4.6 Yi6_copy
>  - 4.6 Yi7_copy - 21.5 Yi8_copy - 21.5 Yi9_copy

> Subject To
>  RTBH____: + 9 Yi9_copy + 9 Yi8_copy + 4 Yi7_copy + 4 Yi6_copy
>  + 4 Yi5_copy + 2 Yi4_copy + 2 Yi3_copy + 2 Yi2_copy + 7 Yi1_copy
>  + 7 Yi0_copy <= 10

> Bounds
>  1 <= Yi0_copy <= 1
>  0 <= Yi1_copy <= 1
>  0 <= Yi2_copy <= 1
>  0 <= Yi3_copy <= 1
>  0 <= Yi4_copy <= 1
>  0 <= Yi5_copy <= 1
>  0 <= Yi6_copy <= 1
>  0 <= Yi7_copy <= 1
>  0 <= Yi8_copy <= 1
>  0 <= Yi9_copy <= 1

> Generals
>  Yi0_copy
>  Yi1_copy
>  Yi2_copy
>  Yi3_copy
>  Yi4_copy
>  Yi5_copy
>  Yi6_copy
>  Yi7_copy
>  Yi8_copy
>  Yi9_copy

> End


> Andrew Makhorin wrote:
>> 
>>> in particular, in the cplex lp file Yi0_copy should be
>>> specified as follows:
>> 
>>> Bounds
>>>  Yi0_copy = 1
>> 
>> This is not necessary, because glp_read_lp correctly set the types
>> of variables having identical lower and upper bounds to GLP_FX.
>> 
>> 
>> 
>> _______________________________________________
>> Bug-glpk mailing list
>> address@hidden
>> http://lists.gnu.org/mailman/listinfo/bug-glpk
>> 
>>