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Production Formulas
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Taesith
#1 - 2014-07-28 18:38:36 UTC
This is the formula I put together for production, is it correct?

=MAX( runs, CEILING( #of unresearched materials * me * runs * station bonus * team bonus 1 * team bonus 2, 1))

and the production fee is:

=Base cost * System Cost Index * (1+ Tax) * (1+ Team Salary) * Runs
Where the base cost is the sum of the total unresearched materials times the adjusted price of each material
and the system cost index is directly off the CREST API.
Qoi
Exert Force
#2 - 2014-07-28 23:29:53 UTC  |  Edited by: Qoi
Your formulas are mathematically correct, the production formula technically might lead to off by one errors.

There are some issues because floating point multiplication isn't associative ( for example 104*0.9*60 = 104*60*0.9 + 9.094947017729282*10^-13 ) , you might want to reorder the factors in your formula so that the number of runs comes last, although it is not clear in what order CCP is doing these multiplications either. But you certainly want to multiply base quantity and ME factor first and then runs.

I currently use
Quote:

max($runs, ceil($base_quantity * $material_mod * round(1.0 - $me/100.0, 2) * $runs))

(Leaving out the round or switching the order of runs and the material efficiency factor leads to off by one errors for me.)

Note: I have no experience with spreadsheets, but i assume they use floating points like everything else. If they do something "smart", it might be completely impossible to get the correct numbers in every case.

http://eve-industry.org
Qoi
Exert Force
#3 - 2014-07-29 12:47:42 UTC  |  Edited by: Qoi
Okay, as of patch today the formula should be (pending further investigation)

Quote:

max($runs, ceil(round($base_quantity * $material_mod * (1.0 - $me/100.0) * $runs, 2)))

http://eve-industry.org