gemseo.mlearning.transformers.power.yeo_johnson module#
A Yeo-Johnson power transformation.
Transform \(x\) as:
\[\begin{split}y = & ((x + 1)^\lambda - 1) / \lambda, \text{ for } x \geq 0, \lambda \neq 0 \\
& \log(x + 1), \text{ for }x \geq 0, \lambda = 0 \\
& -\frac{(1-x)^{2 - \lambda} - 1}{2-\lambda}, \text{ for } x < 0, \lambda \neq 2\\
& -log(1-x), \text{ for } x < 0, \lambda = 2\end{split}\]
Dependence#
This transformation algorithm relies on the PowerTransformer class
of scikit-learn.