Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Specialized Linear Program
Replies: 4   Last Post: Apr 27, 2013 9:38 AM

 Messages: [ Previous | Next ]
 quasi Posts: 12,067 Registered: 7/15/05
Re: Specialized Linear Program
Posted: Apr 25, 2013 10:23 PM

quasi wrote:
>analyst41 wrote:
>>
>>Max sum over j, c(j).x(j)
>>St
>> sum over j, a(i,j).x(j) <= b(i) for i = 1,2,..m.
>> x(j) >= 0 for j = 1,2,...n.
>>
>>All a's,b's and c's are >= 0.
>>
>>This LP has the property that x feasible implies x' feasible
>>whenever 0 <= x'(j) <= x(j) for all j.
>>
>>Are these problems any easier than general LPs?

>
>Not as far as I can see.
>
>The only difference is that you have a known vertex of the
>feasible region, namely the origin, and that the feasible region
>is entirely in the first orthant.

Forget the first orthant part -- that's automatic just from
x(j) >= 0 for all j.

>Given any LP with a known vertex of the feasible region, a
>change of coordinates can be used to achieve another LP
>in the form you specify above.

I'm not so sure about the above.

Maybe there's some advantage after all.

quasi

Date Subject Author
4/25/13 analyst41@hotmail.com
4/25/13 quasi
4/25/13 quasi
4/26/13 RGVickson@shaw.ca
4/27/13 analyst41@hotmail.com