Solver and integers

Hello Excel experts,

I am using Excel Solver and the parameters to be changed is the Month (so an integer, and a non integer values would be interpretated as days, which is not allowed in my case). I use Tolerance at 0.1% and if I put the solver in 'Show Iteration Results' mode, I see the value (which I declared as integer) being changed as a real (the month becomes for instance 11.00003, while I would like to see 10, 11, 12).

Any help. Thanks for your help on this. I am trying to use Solver to see when (which month and year) a particular sundial is best showing the time.

Thanks all the best,


Victor

P.S. WIndows XP
excel 2003

Perhaps changing the formate of the target cell to number formate with no decimals will solve your display problem?

Originally Posted by Alf

Perhaps changing the formate of the target cell to number formate with no decimals will solve your display problem?

I tried it, but this does not help (I think formatting is only a presentation option, not a definition of the type of variable in a spreadsheet).

Still searching for a solution on this...

Originally Posted by VReijs

I tried it, but this does not help (I think formatting is only a presentation option, not a definition of the type of variable in a spreadsheet).

Still searching for a solution on this...

Given the finite precision of computers the solver has tolerances build into it. It assumes that 11.00003 is close enough to an integer value. You can try tightening down the one such tolerance it allows you access to. Select Tools|Solver and then the Options button. The Default setting for Precision is 0.000001. Try making it smaller (perhaps even 0). If this does not affect things you could send me your model -- there may be more I can suggest after looking at it.

Mark
mark(at)lindo.com

Originally Posted by markwiley

Given the finite precision of computers the solver has tolerances build into it. It assumes that 11.00003 is close enough to an integer value.

The problem is that the Solver does not add an integer value as it only adds 0.0003 and not 1 or 2 or something like that.

Originally Posted by markwiley

If this does not affect things you could send me your model -- there may be more I can suggest after looking at it.

Will work on this, the problem is that it needs another Add-In (made by myself), which needs to be added in that case...
Will see if I can reproduce the problem in a smaller environment (without this Add-In).
Thanks for offering to look at it.

All the best,


Victor