Macro Sover Loop Help

[Fiona149]

I am very new to Macro!

I have a simple solver program that wants to go through columns rather than rows. I had a play about to try and model this but it says there is a global error
How do I go about this?

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Please help!
Thank you

[Kaper]

Hi,

Isn't a problem caused by trying to add i within quotation marks?

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[Fiona149]

Thank you!
This has solved my problem!
Also, my solver command in this macro isn't finding the best solution, is there a reason for this?

[MrShorty]

Short but useless answer, I'm sure there is a reason it is not finding the best solution. It will probably be next to impossible to talk more specifically without seeing the actual model you are using.

One common reason that I see is users who don't really understand how Solver finds solutions. By default, Solver uses Newton-Raphson type algorithms. These kind of algorithms start where you tell them to start, and go downhill until they get to the bottom of a valley. However, these kind of algorithms have no way of knowing if the valley they found is the lowest possible valley. In order to find the lowest possible valley using NR type algorithms, you have to know where to start the search so you are somewhere on the slope that leads into the lowest possible valley.

Or you could try the Evolutionary algorithm (available in Solver after Excel 2010). I don't fully understand how EA algorithms work, but they sometimes do better in cases where there are multiple valleys because these algorithms can use multiple "seed" values.