On Dec 7, 10:59*pm, Kerry wrote:
On Dec 7, 5:33*pm, "Mike Middleton"
wrote:



Kerry *-

Are there otherSolverlimitations I need to know about that could be
causing the issue? <

Bernard Liengme suggested *checkingwww.solver.com, where you will see that
PremiumSolvercan automatically transform nonsmooth functions like IF, MIN,
MAX, ABS, AND, OR, and NOT. As you have found, standardSolvergenerally
cannot.

For the standardSolveradd-in shipped with pre-2010 Excel, Tushar Mehta
suggested a workaround for dealing with the nonsmooth IF function using a
binary variable.

For a brief description of these issues, seehttp://www.solver.com/xlsplatformb.htm

What is a binary variable in excel, how do I incorporate it and wouldn't
it also cause the function gaps or sudden jumps thatSolverhas issues
with? <

A binary variable is restricted to the values zero or one. On theSolver
Parameters dialog box, you click the Add button (for the Constraints),
specify the cell reference where your model's binary variable is located,
and use the unlabeled "relationship" drop-down list to select "bin," which
automatically enters "binary" in the Constraint edit box.

Using a binary variable does not have the same issues as a nonsmooth
function, becauseSolveruses a different algorithm for model formulations
that contain a binary or integer variable.

- *Mikehttp://www.MikeMiddleton.com

Thanks for the info. I looked atSolver.com but the program that
features the IF function "linearizer" is $3000+! I'm a poor student,
so...But I also feel like I got so close (see last post)! I'd feel
like a overcame a challenge if I got it to work. I still don't quite
get the example provided by Tushar Mehta but at least I know what he
meant be adding a binary constraint. I'll keep working at it.

Thanks,
k

Trying Solver.com program now w/ free trial. First run was way off. I
actually think I have the optimal solution visually so I have a good
min value I know exists. I'm using the evolutionary algorithm as
suggested in the help file for non-smooth functions. I also have
placed bounds on all the variables. I think I will narrow the bounds
next time and let it run all night if possible), that is, if I can
ever get the first run to stop! I total it stop when it reached the
time limit and alse pressed pause. Now it just says it's "pausing..."
and keeps going