Re: [Help-glpk] Transport Problem advanced

[SpaceRider]

Hi!

sum{i in I} x[i,j] >= b[j] * c[j];

That's what I wanted, but I have still one problem:

The binary flag c[j] is only set to 1 if supply[i] = demand[j] :(

But I want it is set to 1 if sum{i in I} x[i,j] >= demand[j]

Did you give an idea?

Andy


Bruno Rosell i Gui wrote:
> 
> Hi!
>> // s.t. supply{i in I}: sum{j in J} x[i,j] = a[i];
>> s.t. supply{i in I}: sum{j in J} x[i,j] = a[i]; // process all offer
>>
>> s.t. demand{j in J}: sum{i in I} x[i,j] >= b[j];
>>
>> Now, I need a additional comparison, but not a range from to
>> sum{i in I} x[i,j] >= b[j] OR sum{i in I} x[i,j] = 0
>>
>> How I have to write the syntax?
>> Is it still a LP-Problem?
>>
>> Can someone help me?
> 
> It depends if 'b' is a parameter you could use a binary variable ( 'c' )
> and 
> write:
> 
> sum{i in I} x[i,j] >= b[j] * c[j];
> 
>  Or you can use something like descirbed in the next posts:
>  http://www.mail-archive.com/address@hidden/msg01467.html )
> http://www.mail-archive.com/address@hidden/msg00816.html
> http://www.mail-archive.com/address@hidden/msg01153.html 
> http://www.mail-archive.com/address@hidden/msg02021.html
> 
> But if 'b' is a variable , i don't known how to solve
> 
> -- 
> 
>  Cordialment Bruno Rosell i Gui
> ______________________________________________
> Help-glpk mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/help-glpk
> 
> 

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