174 Optimizing Optimization
Some auxiliary parameters
μ
σ
ln(Dif)
2
α
πσ
1
() 2
β
σ
1
() 2 2
Formula 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
τ
2
If the extreme value is a maximum and x is less than the extreme value, then:
f( )x exp( (ln( ) ) )
x
x
α
βμ
τ
τ^2
Formula 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
22
f τ μ
σ
DifDif MeanMean TauTau
σln
SD
Dif
⎛
⎝
⎜⎜
⎜⎜
⎞
⎠
⎟⎟
⎟⎟
⎛
⎝
⎜⎜
⎜⎜
⎜
⎞
⎠
⎟⎟
⎟⎟
⎟⎟
2
σln 1
SD
Dif
⎛
⎝
⎜⎜
⎜⎜
⎞
⎠
⎟⎟
⎟⎟
⎛
⎝
⎜⎜
⎜⎜
⎜
⎞
⎠
⎟⎟
⎟⎟
⎟⎟
2
1