scipy.special.boxcox1p

scipy.special.boxcox1p(x, lmbda) = <ufunc 'boxcox1p'>

Compute the Box-Cox transformation of 1 + x.

The Box-Cox transformation computed by boxcox1p is:

y = ((1+x)**lmbda - 1) / lmbda  if lmbda != 0
    log(1+x)                    if lmbda == 0

Returns nan if x < -1. Returns -inf if x == -1 and lmbda < 0.

Parameters:

x : array_like

Data to be transformed.

lmbda : array_like

Power parameter of the Box-Cox transform.

Returns:

y : array

Transformed data.

Notes

New in version 0.14.0.

Examples

>> boxcox1p(1e-4, [0, 0.5, 1]) array([ 9.99950003e-05, 9.99975001e-05, 1.00000000e-04]) >>> boxcox1p([0.01, 0.1], 0.25) array([ 0.00996272, 0.09645476])