Dataset:  olive_oil.dat

Source: E. Monteleone, G.Caporale, A. Carlucci, E. Pagliarini (1998).
"Optimization of Extra Virgin Olive Oil Quality," Journal of the Science of Food and
Agriculture, Vol. 77, pp.31-37.

Description: Results of a 2^4 factorial experiment with factors:
Ripening (% pigmentation, levels=30,70)
Storage (days, levels=1,5)
Mixing Temperature (C, levels=23,34)
Mixing Time (minutes, levels=30,80)

Responses:
Total phenols (mg/kg)
dphenols (Tranformed phenols)
Percent yield 
dyield
COI Score
dCOI
Dtot = Geometric mean of dscores

Model fit contained all main effects and 2-way interactions for Dtot

variables/columns
Ripening 7-8
Storage  16
MixTemp   23-24
MixTime   31-32
total phenols  38-40
dphenols   45-48
pctyield   53-56
dyield    61-64
COI score 70-72
dCOI      78-80
Dtot      85-88