Clp newbie needs help

[svigerske]

Issue created by migration from Trac.

Original creator: GCRhoads

Original creation time: 2011-03-04 16:35:33

Assignee: somebody

Version:

Hi,

I'm new to Clp and am having trouble figuring out how to use it for my research application. What I want to do is create a very small LP (anywhere from 4 variables with 4 constraints to 12 variables with 12 constraints) and then solve many, many LPs of that size.

I couldn't find any examples of changing a single specific coefficient. How do you change the coefficient in row r, col c, to some new value?

What's the best way to set up an initial small LP of the sizes I'm interested in and then changing the coefficients as necessary?
Note that I won't be reading in the LPs from a file, I'll be setting
them up from within my C++ program (the examples I looked at had the
data read in from a file).

The following is a typical LP that I need to solve. There are 5 variables which I will call v, w, x, y, and z.

Maximize Z
such that
           1.185 w - 0.306 x - 3.156 y - z >= 0
-1.185 v           + 0.758 x - 2.286 y - z >= 0
 0.306 v - 0.758 w           + 0.182 y - z >= 0
 3.156 v + 2.286 w - 0.182 x           - z >= 0
       v       + w       + x       + y      = 1
v,w,x,y >= 0
z unrestricted

If I knew how to set up this LP and how to change specific coefficients of it, then I would know everything I need to for my particular application. I would really appreciate it if somebody would help me out. You can send email to me at
rhoads@cs.rutgers.edu

[svigerske]

Comment by @LouHafer created at 2011-03-04 16:38:32

Closed. Use the clp mailing list, clp@list.coin-or.org.

[svigerske]

Comment by @LouHafer created at 2011-03-04 16:38:32

Resolution: invalid