Opened 9 years ago

Closed 9 years ago

#42 closed task (invalid)

Clp newbie needs help

Reported by: GCRhoads Owned by: somebody
Priority: major Milestone:
Component: component1 Version:
Keywords: Cc:

Description

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@…

Change History (1)

comment:1 Changed 9 years ago by lou

  • Resolution set to invalid
  • Status changed from new to closed

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