Box-Cox transformation

To transform non normal distributed data to a more normal distributed dataset.

Formula to find optimum Lamda

Out of this data the STDEV is calculated. And Develve searches for the smallest STDEV between a labda -10 till 10.

Formula for transformation

Legend

s = STDEV
Geometric mean =

Example

External links

• http://en.wikipedia.org/wiki/Power_transform
• http://www.isixsigma.com/tools-templates/normality/making-data-normal-using-box-cox-power-transformation/
• http://onlinestatbook.com/2/transformations/box-cox.html