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#1
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Solver. When a model is liner and when it's not?
If I use a function like MAX in my xls model, does that makes my model non
linear? My solver (xls 2000) is not working with non linear models... Tx, PV |
#2
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Solver. When a model is liner and when it's not?
It's even worse than non-linear. A simple non-linear system might be Y=X*X.
What you are describing is a discontinuous function - one with breakpoints where the equation changes. In my experience Solver can deal with simple non-linear systems, but is totally unable to deal with discontinuous functions. My approach for discontinuous systems is to solve them "manually". If I have some system Y=f(X) then I will create a table of X values I want evaluated and write a macro to repeatedly plug those X values into the spreadsheet and pull back the resultant Y into that table. Then you can easily plot the table and see what you've got. I find the need to do this because heavily discontinuous systems (1000 If/then statements say) may result in very narrow spikes in the response function that may be significant, or may not. You've got to examine them by eye to decide. More than you wanted to know. Good luck... Bill --------------------- PV wrote: If I use a function like MAX in my xls model, does that makes my model non linear? My solver (xls 2000) is not working with non linear models... Tx, PV |
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