inv_transform.py

import numpy as np
def inv_yeojohnson(value, lmbda):
    if value>= 0 and lmbda == 0:
        return np.exp(value) - 1
    elif value >= 0 and lmbda != 0:
        return (value * lmbda + 1) ** (1 / lmbda) - 1
    elif value < 0 and lmbda != 2:
        return 1 - (-(2 - lmbda) * value + 1) ** (1 / (2 - lmbda))
    elif value < 0 and lmbda == 2:
        return 1 - np.exp(-value)