A collection of pre-processing (outlier detection and normalization) models that can be fit via polars expressions, either directly on a dataframe or in a groupby context. All only work with univariate data at present.
Computes the mean and standard deviation of the data. Upon predict, subtracts the mean and divides by the standard deviation.
Removes all values that occur more than a specified threshold of standard deviations away from the mean.