174 Optimizing Optimization
Some auxiliary parameters
μσ
ln(Dif)
2α
πσ1
() 2β
σ1
() 2 2Formula for the lognormal curve f ( x )
If the extreme value is a minimum and x is greater than the extreme value,
then:
f( )x exp( (ln( ) ) )
x x
α
βτμ
τ2If the extreme value is a maximum and x is less than the extreme value, then:f( )x exp( (ln( ) ) )
x x
α
βμ
ττ^2Formula for the lognormal cumulative distribution function F ( x )
If the extreme value is a minimum and x is greater than the extreme value,
then:
Fx
er c x
()
(ln( ) )
1
22f τ μ
σDifDif MeanMean TauTauσlnSD
Dif⎛
⎝⎜⎜
⎜⎜⎞
⎠⎟⎟
⎟⎟⎛⎝⎜⎜
⎜⎜
⎜⎞⎠⎟⎟
⎟⎟
⎟⎟2
σln 1SD
Dif⎛
⎝⎜⎜
⎜⎜⎞
⎠⎟⎟
⎟⎟⎛⎝⎜⎜
⎜⎜
⎜⎞⎠⎟⎟
⎟⎟
⎟⎟2
1