Originally posted by: Yeahoos

When I run the macro "Example" in the attached workbook, I get the error:

Failed to setup optimization problem.
Error 24: Cannot convert value to number.

There is one variable. The coefficient on the variable in the objective function is 0.2 divided by the sum of other data (the sum is 46). I'm guessing this is why I am getting the error, but it seems like something I should be able to do, right? I am dividing by data to get an objective coefficient. Variables are not used as divisors.

Any ideas?
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: Yeahoos

I guess I wasn't able to post my workbook. Here is the macro:

Sub Example()
CPXclear
CPXaddVariable Variable:=ActiveSheet.Cells(5, 3), Lb:=4, Ub:=6
CPXsetObjective ObjCell:=ActiveSheet.Cells(6, 3), Sense:=2

CPXsolve
End Sub

The sheet has a values of 34, 0, and 12 in C1, D1, and E1, resp. Cell C4 has the formula "=0.2/(SUM(C2:E2)+1)". Cell C6 has the formula "=C4*C5".
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

According to your post the formula in cell C4 references C2, D2 and E2. You gave only data for C1, D1, and E1. Is this a typo or does C2 indeed reference empty cells?
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: Yeahoos

Sorry, yes, the data are in C2, D2, and E2; C1:E1 are blank.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Does it help to replace the formula

=0.2/(SUM(C2:E2)+1)

by the equivalent expression

=0.2/(C2 + D2 + E2 + 1)

?
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: Yeahoos

Yes, it does. It compiles and runs with no errors with the 'SUM' function removed. What gives?
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Looks like you have found a bug in the CPLEX Excel connector :-(
I have filed a bug report.
Right now the only workaround I see is to use '+' instead of SUM.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: Yeahoos

Ok, thanks for following up. I'll look for the fix. In the meantime, I'm just using VB to call CPLEX which works really nicely.
#CPLEXOptimizers
#DecisionOptimization