Re: [Help-glpk] Different results from gusek and glpk-java API using same data

[xypron]

Hello Sana,

sorry, the API description is of cause in doc/glpk.pdf.

Best regards

Xypron


xypron wrote:
> 
> Hello Sana,
> 
> looking at doc/gmpl.pdf you will find that different API functions are
> used
> for pure linear problems and mixed integer problems.
> 
> To solve a mip use glp_intopt(lp, iocp).
> To retrieve a mip solution use glp_mip_col_val(lp, i).
> 
> Please, have a look at examples/java/Mip.java, compare it to 
> examples/java/Lp.java
> 
> If you want to know how the standalone solver glpsol uses the API study
> the code in src/glpapi20.c.
> 
> Best regards
> 
> Xypron
> 
> 
> Sana Jawad wrote:
>> 
>> Hello,
>> 
>> I am calling my model written in MathProg from java using glpk-java API.
>> In
>> my model I have a variable named "assign"
>> 
>> var assign{w in Weekdays,s in Shifts,p in People,j in Skills},integer,>=
>> 0,
>> <= 1;   /*Indicates a shift assignment*/
>> 
>> When I solve it through gusek I always get a binary solution. But When I
>> call it from java and display the value using these statements:
>> 
>> for(int i=1; i <= n; i++)
>>             {
>>              name = GLPK.glp_get_col_name(lp, i);
>> 
>>              val=GLPK.glp_get_col_prim(lp, i);
>>             System.out.print(name);
>>             System.out.print(" = ");
>>             System.out.println(val);
>> 
>>             }
>> 
>> I see a few non-binary values like :
>> 
>> assign[Mon,1,Abe,cashier] = 4.440892098500571E-17
>> assign[Mon,1,Charles,cashier] = -1.0362081563168091E-16
>> 
>> Their value is "0" in gusek output
>> These variables have an effect on the values of other variables as well.
>> Although the value of object function remains unchanged.
>> 
>> The strange thing is that I have display statement after solve statement
>> in
>> my model. Its output on my console does not have any non-binary value.
>> But
>> the result has non-binary values when I access the values using the code.
>> 
>> Can any one please help me.
>> 
>> Best Regards,
>> Sana
>> 
>> _______________________________________________
>> Help-glpk mailing list
>> address@hidden
>> http://lists.gnu.org/mailman/listinfo/help-glpk
>> 
>> 
> 
> 

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