From: me13013 on
Howdy,

I have a small linear programming problem that I would like to solve
for all integer solutions:

5a + 3b + 2c + 6d + 5e + f = 25
a + b + c <= 4
d + e + f <= 5
a,b,c,d,e,f >= 0

How can I pose this problem to Mathematica?

I have looked at (and fiddled around with) the LinearProgramming
function, but I don't see how to make ti give me the solution(s) I am
looking for.

Thanks for any help,
Bob H

From: Murray Eisenberg on
Reduce[{5 a + 3 b + 2 c + 6 d + 5 e + f == 25,
a + b + c <= 4,
d + e + f <= 5,
a >= 0, b >= 0, c >= 0, d >= 0, e >= 0, f >= 0},
{a, b, c, d, e, f}, Integers]

On 5/2/2010 5:35 AM, me13013 wrote:
> Howdy,
>
> I have a small linear programming problem that I would like to solve
> for all integer solutions:
>
> 5a + 3b + 2c + 6d + 5e + f = 25
> a + b + c<= 4
> d + e + f<= 5
> a,b,c,d,e,f>= 0
>
> How can I pose this problem to Mathematica?
>
> I have looked at (and fiddled around with) the LinearProgramming
> function, but I don't see how to make ti give me the solution(s) I am
> looking for.
>
> Thanks for any help,
> Bob H
>

--
Murray Eisenberg murray(a)math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305

From: Harvey P. Dale on
Bob:

Reduce[{5 a + 3 b + 2 c + 6 d + 5 e + f ==== 25 && a + b + c <== 4 &&
d + e + f <== 5 && a >== 0 && b >== 0 && c >== 0 && d >== 0 && e >== 0 &=
&
f >== 0}, {a, b, c, d, e, f}, Integers]

Best,

Harvey

-----Original Message-----
From: me13013 [mailto:me13013(a)gmail.com]
Sent: Sunday, May 02, 2010 5:36 AM
Subject: how to solve for all integer solutions, linear
programming

Howdy,

I have a small linear programming problem that I would like to solve
for all integer solutions:

5a + 3b + 2c + 6d + 5e + f == 25
a + b + c <== 4
d + e + f <== 5
a,b,c,d,e,f >== 0

How can I pose this problem to Mathematica?

I have looked at (and fiddled around with) the LinearProgramming
function, but I don't see how to make ti give me the solution(s) I am
looking for.

Thanks for any help,
Bob H

From: Ladislav Lukas on
On 2 kv=C4=9B, 11:35, me13013 <me13...(a)gmail.com> wrote:
> Howdy,
>
> I have a small linear programming problem that I would like to solve
> for all integer solutions:
>
> =C2 5a + 3b + 2c + 6d + 5e + f = 25
> =C2 a + b + c <= 4
> =C2 d + e + f <= 5
> =C2 a,b,c,d,e,f >= 0
>
> How can I pose this problem to Mathematica?
>
> I have looked at (and fiddled around with) the LinearProgramming
> function, but I don't see how to make ti give me the solution(s) I am
> looking for.
>
> Thanks for any help,
> Bob H

Hello Bob,
Try the following:
xLP = LinearProgramming[{-1, -1, -1, -1, -1, -1}, {{5, 3, 2, 6, 5,
1}, {1, 1, 1, 0, 0, 0}, {0, 0, 0, 1, 1, 1}}, {{25,
0}, {4, -1}, {5, -1}}]
zvalLP = xLP.{-1, -1, -1, -1, -1, -1}

and you should get the solution:
{4, 0, 0, 0, 0, 5}
-9
Ladislav