Distribution based on a non-monotonic (u- or hump-shaped transformation)
the constructor can be called with a distribution class, and functions that define the non-linear transformation. and generates the distribution of the transformed random variable
Note: the transformation, it’s inverse and derivatives need to be fully specified: func, funcinvplus, funcinvminus, derivplus, derivminus. Currently no numerical derivatives or inverse are calculated
This can be used to generate distribution instances similar to the distributions in scipy.stats.